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Pasqualini U, Pasqualini ME. Treatise of Implant Dentistry: The Italian Tribute to Modern Implantology. Carimate (IT): Ariesdue; 2009 Oct.

Cover of Treatise of Implant Dentistry

Treatise of Implant Dentistry: The Italian Tribute to Modern Implantology.

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in collaboration with Paolo Zampetti


Despite the fairly recent rise of oral implantology from a scientific point of view, it must be remembered that the origins of this discipline go back to ancient times.

There are well-known descriptions of archaeological findings from the pre-Columbian era exhibiting stone inlays in teeth or even used to replace missing dental elements (1).

It is known that the Maya used bow drills (Fig. 1) to perform the “cosmetic” filing of natural teeth on live individuals, and tooth shaping varied according to regions and tribes. Malvin E. Ring reports that they were also skilled at inlaying very well-carved stones in meticulously prepared cavities on the labial surface of the front teeth and sometimes in premolars. These inlays, which served a purely aesthetic purpose, were made of a great variety of rounded minerals of different colors, such as turquoise, quartz, serpentine and cinnabar (Fig. 2) (2).

Fig. 1. The manual drill used for tooth filing by the Maya.

Fig. 1

The manual drill used for tooth filing by the Maya.

Fig. 2. Upper front teeth of a Maya individual from the 8th century AD.

Fig. 2

Upper front teeth of a Maya individual from the 8th century AD.

The cavities were undoubtedly prepared in living teeth. According to Ring, ancient oral surgeons would spin a round hard tube similar in shape to a drinking straw, originally made of jade and later of copper (Fig. 3), between their hands or using a bow drill, applying a slurry of powdered quartz in water as an abrasive to cut a perfectly round hole in the enamel and dentin. The carved stones were then set in these cavities, fitting them so perfectly that many have remained in place for thousands of years (2, 3).

Fig. 3. Enlargement of the drill tip, originally made of jade and later of copper.

Fig. 3

Enlargement of the drill tip, originally made of jade and later of copper.

Nevertheless, the first successful implant treatment survived to us is represented by the renowned mandible fragment with three implanted shell valves. The Peabody Museum of Archaeology and Ethnology at Harvard University had a mandible fragment from an individual who lived between the 7th and 8th centuries AD, with three cuneiform shell pieces in place of the three lower incisors (Fig. 4) (4). The fragment was discovered by Dr. Wilson Popenoe and his wife Dorothy during research on the Mayan civilization at Playa de los Muertos, on the right bank of the Rio Ulúa in Honduras, where other important excavations had also been conducted by the archaeologist Gordon.

Fig. 4. The Maya mandible found by Amedeo Bobbio.

Fig. 4

The Maya mandible found by Amedeo Bobbio.

In studying this unusual finding, the expedition members at first conjectured that the inserted elements may have been a postmortem cosmetic treatment, possibly as part of a complicated funerary ritual or religious practice (4, 5).

Two years later the fragment was given to the Peabody Museum. Catalogued as N. 20/54, it was believed to be the evidence of a Mayan burial ritual, as the three tooth-shaped wedges appeared to have been inserted posthumously. A few years later, however, the artifact disappeared.

It would certainly have been forgotten if the Italian Amedeo Bobbio, born in Genoa and residing in Brazil, where he practiced dentistry and was professor of Implantology at the University of Santos, hadn’t “rediscovered” it, providing scientific evidence that the three shells were inserted during life and that they represent the most ancient evidence of alloplastic implants performed on humans (6).

In his capacity as a dental historian, the distinguished stomatologist wanted to research several Mayan findings that were already well known. Specifically, he wanted to investigate the report of “a black stone” implanted in place of a lateral lower incisor into the mandible of a skeleton discovered almost 80 years earlier by the archaeologist R. R. Andrews among the ruins of the Mayan metropolis of Copán (Honduras), and preserved at the Peabody Museum (Fig. 5).

Fig. 5. Original drawing of the lower incisors, published in Andrews’s paper (1893): decayed teeth, with no inlays or cement residue (5 and 6); the famous implanted lateral incisor, made of black stone (8); decayed bicuspid and large alveolar fragment (8).

Fig. 5

Original drawing of the lower incisors, published in Andrews’s paper (1893): decayed teeth, with no inlays or cement residue (5 and 6); the famous implanted lateral incisor, made of black stone (8); decayed bicuspid and large alveolar fragment (more...)

In place of this finding, which had unfortunately vanished, Bobbio made another interesting discovery.

In my search in every sector of the museum, I suddenly made an unexpected and important discovery: a wide and compact mandibular fragment, almost the whole body, more mutilated to the right and without the ascending branches. The dental formula of the teeth that are present is as follows: lateral incisor and canine on the right side; canine, premolars, first and second molars on the left (Fig. 6). The extraordinary thing is that the three missing incisors were replaced with three implanted artificial teeth made of shell valves.

The resemblance to natural teeth is simply astonishing, even if morphologically they have a very flattened anteroposterior appearance.

As a whole, the shape, including the endosseous radicular portion, suggests the idea of a triangle lengthened to form a wedge. . . . In the fragment the natural teeth do not show any sign of decay, but in the natural teeth of the left hemiarch small fracture lines of the enamel are visible, mostly horizontal on the labial aspect, but also vertical ones on the canine.

The implants were characterized by a small transversal groove made carefully below the incisal margin, especially the left lateral incisor.

The artificial left incisor is implanted abnormally, rotated on itself at an angle of about 80 degrees, so that the labial aspect, which has a larger horizontal diameter, is on the side, perpendicular to the other teeth. This is at least its current appearance, which is clearly visible in my picture, because the photographs held by the museum, taken in 1935 and slightly blurred, show a much less pronounced anomaly. It is likely that the tooth fell at a certain point and was thus forced back into this irregular position. There is no literature on this mandible and little or nothing was known until today.

However, looking once again through the correspondence of the Peabody Museum, I found some information in a letter dated May 2, 1956 written by the then-director J.O. Brew to the British implantologist Boris Trainin, who had requested details about a “skull with implanted teeth.” In his reply, Brew indicated that the mandible with the three implanted incisors (reporting the opinion of members of the same expedition) dated back to the 8th century AD, specifying that the teeth were implanted postmortem, perhaps as part of a funeral ritual. . . . My point of view is substantially different. On June 25, 1970, at the Harvard Medical School I had the fortune to perform the radiographic examination of all the mandibular teeth for the first time (Figs. 79). We found incontrovertible elements that allowed us to prove the presence of compact bone osteogenesis even around the implanted teeth, which were highly stable and were probably inserted with a technique very similar to the current ones of [Leonard] Linkow and [Giordano] Muratori. Based on the radiographic image of the natural teeth, which have incomplete apexes, and the features of the relatively small mandibular body, it appears to be a twenty-year-old womanly fragment.

In conclusion, this would appear to be the first authentic endosseous alloplastic implants survived to us, performed on live subjects, and which had certainly been in service for several years (Fig. 10) (4, 6, 7).

Fig. 6. Enlargement of the Maya mandible studied by Bobbio.

Fig. 6

Enlargement of the Maya mandible studied by Bobbio.

Fig. 7. Original radiograph of the three “immediate load” shell implants.

Fig. 7

Original radiograph of the three “immediate load” shell implants.

Fig. 8. The X-ray of the canine and premolars contralateral to the area of the “implanted” teeth demonstrates that the mandible belonged to a young individual, given the large root canals and radicular apexes.

Fig. 8

The X-ray of the canine and premolars contralateral to the area of the “implanted” teeth demonstrates that the mandible belonged to a young individual, given the large root canals and radicular apexes.

Fig. 9. The X-ray of the left molars and premolars of the archaeological finding; the open apexes of the premolars prove that the mandible belonged to individual of about 20 years of age.

Fig. 9

The X-ray of the left molars and premolars of the archaeological finding; the open apexes of the premolars prove that the mandible belonged to individual of about 20 years of age.

Fig. 10. This radiographic image clearly shows the bone inclusion of two valve shell implants with the formation of two new alveolar housing cavities (arrows).

Fig. 10

This radiographic image clearly shows the bone inclusion of two valve shell implants with the formation of two new alveolar housing cavities (arrows). The radiographic appearance is different, as the central implant is rotated; it probably fell and was (more...)

Bobbio’s valuable research confirmed the exceptional fact that 700 years before Francesco Pizarro brought our “culture” to the New World, Central American populations already had a distinct civilization that was no less evolved than that of Europeans (8).

It would be interesting to know the surgical technique employed to insert the three implants found after so many years and maintained in situ by a bony compact formation “radiographically similar to the one that would surround a contemporary implant.” They were unquestionably plunged into freshened sockets, since Bobbio radiographically demonstrated the bone reaction that led to their inclusion during life. The time required to prepare the three implants could not have been so short that it would have prevented the sockets from healing, unless the inserts were already prepared and ready to fit. Anesthesia should not have been a problem, given the ascertained knowledge of North American populations on the hallucinogenic and anesthetizing properties of coca leafs and certain types of mushrooms, nor should it have been difficult to drill the sockets with manual bow drills, probably using the same “burs” employed to prepare the aesthetic inlays on the labial surface of the front teeth.

The answer to the question of how those first (and, until now, unique) alloplastic implants were temporarily fixed during the phase of reparative osteogenesis probably lies in the horizontal grooves, which seem to represent the retentive site of a temporary ligature.

Recent and exhaustive histological research on the behavior of shell fragments in direct contact with bone tissue in animal experiments has confirmed the principle of osseointegration between the two tissues1 (Figs. 1123) (9).

Fig. 11. The Tridacna used to make the shell fragments for the experiment.

Fig. 11

The Tridacna used to make the shell fragments for the experiment.

Fig. 12. The prepared Tridacna “implants”.

Fig. 12

The prepared Tridacna “implants”.

Fig. 13. Flap opening and exposure of the rat tibial bone with the site receiving the shell fragments.

Fig. 13

Flap opening and exposure of the rat tibial bone with the site receiving the shell fragments.

Figg. 14, 15. Endosseous cavities where the shell fragments will be placed.

Figg. 14, 15

Endosseous cavities where the shell fragments will be placed.

Fig. 16. Close-up of the Tridacna “implant.”.

Fig. 16

Close-up of the Tridacna “implant.”.

Fig. 17. Insertion of one of the two artifacts.

Fig. 17

Insertion of one of the two artifacts.

Fig. 18. Rat on the “autoptic” table before samples are taken.

Fig. 18

Rat on the “autoptic” table before samples are taken.

Fig. 19. Macroscopic postmortem image of the bone surrounding the shell fragment three months after surgery.

Fig. 19

Macroscopic postmortem image of the bone surrounding the shell fragment three months after surgery.

Fig. 20. Sample of the tibial fragment with inclusions.

Fig. 20

Sample of the tibial fragment with inclusions.

Fig. 21. Another close-up showing the completed osteogenetic process.

Fig. 21

Another close-up showing the completed osteogenetic process.

Fig. 22. Histological appearance of the bone surrounding the “shell implant”.

Fig. 22

Histological appearance of the bone surrounding the “shell implant”. The peri-implant tissue does not show any trace of fibrous tissue, nor can any evidence of macrophages be detected, but it appears to surround the implant without gaps (more...)

Fig. 23. Magnified detail of Fig. 22 (hematoxylin-eosin, 40×).

Fig. 23

Magnified detail of Fig. 22 (hematoxylin-eosin, 40×). The peri-implant border is brighter, due to the presence of new bone with a higher mucopolysaccharide content, resulting in greater stain uptake.

As to the ability of Maya in carving and adapting hard stones for the most disparate uses, there is impressive documentation of a ritual skull “embellished” with perfectly matched turquoise fragments (Fig. 24). A demonstration of the surgical skills of Central America’s pre-Columbian populations comes from a skull discovered in Peru, showing signs of perforation with rounded edges, partially closed by a bony layer of reossification, which certainly took place during life (Fig. 25) (2, 3, 8).

Fig. 24. Ritual skull embellished with a mosaic of perfectly fitted pieces of turquoise (London British Museum).

Fig. 24

Ritual skull embellished with a mosaic of perfectly fitted pieces of turquoise (London British Museum).

Fig. 25. Human skull (Peru, pre-Columbian period) with signs of surgical perforation.

Fig. 25

Human skull (Peru, pre-Columbian period) with signs of surgical perforation. The partial reossification of the hole proves that the patient survived the surgery.

The Classical Age

We have examples of implant attempts made during the Classical Age that, unfortunately, are unsupported by findings or practical confirmations. Hippocrates2 (5th century BC) wrote about the possibility of anchoring artificial teeth to the gums using gold or silk thread in order to replace extracted elements, advising the practitioner not to “throw away mobile elements or teeth expelled from injured mandibles, but to put them back in place, tying them to the remaining teeth with gold thread” (Fig. 26) (1, 10, 11).

Fig. 26. Gold “splint” ligature of an Etruscan “prosthesis”.

Fig. 26

Gold “splint” ligature of an Etruscan “prosthesis”.

The same recommendation was also made by Aulus Cornelius Celsus (1st century AD) who, in De Medicina, mentioned the possibility of replacing a missing dental element by implanting a tooth taken from a cadaver in subjects who, for various reasons had lost a tooth; however, he did not report if such treatment was successful. Nevertheless, it must also be noted that the chief purpose of these replacements was cosmetic, whereas masticatory physiology was not given much consideration.

The Middle Ages

During the 10th and 11th centuries, important contributions were made by the Arabian school, mainly by Abucalsis (936–1013), one of antiquity’s greatest surgeons. In his work, Kitab al Tasrif, which is entirely about surgery, he devoted long chapters to dental surgery.3 In particular, he described the procedures for replacing lost elements with other teeth—natural or artificial—made of bony fragments from large mammals, sustaining that gold ligatures inserted into the gingival tissue were useful for keeping them in place.

In the Middle Ages, an era typified by mortification of the flesh and vivification of the spirit, very few dealt with dentistry, but one of them was Guy de Chauliac (1300–67).4 In Chirurgia Magna, published in 1363, he extensively discussed dental issues; Chapter 25, in particular, describes an attempt at tooth replantation (1, 12).

Casotti (13) wrote that, less than a century later, the Florentine Michele Savonarola (1384–1461) also recommended the ligature of replanted teeth with linen or silk thread, demonstrating that the practice was well known, despite the few available books of the time.

Nicolò Falcucci subsequently illustrated the technique of dental implantation with the aid of metal ligatures.5

The Renaissance

During the Renaissance, with the definitive affirmation of the field of anatomy various branches of medicine gained momentum, and numerous anatomists and surgeons were also involved in dentistry.

One of them was Ambroise Paré, a military surgeon and one of the leading figures of his time, who proposed tooth replantation as he was quite knowledgeable about maxillofacial trauma caused by firearms. He noted that it was possible to replant teeth that had been “expelled from their sockets accidentally, tying them to the remaining teeth with gold, silver or linen threads, and keeping them tied until stabilization.”

Paré’s description of a dental replantation attempt, reported in Vincenzo Guerini’s History of Dentistry, is fascinating. “A trustworthy person confirmed to me that a princess who underwent dental extraction had the tooth immediately replaced with one from a young lady-in-waiting. The tooth became fixed and some time later she (the princess) chewed on it, just as she had done with the tooth that had been removed” (14).

The Frenchman Dupont, a contemporary of Paré, introduced a highly original therapy for pulpitic pain: extraction of the tooth followed by immediate replantation. Dupont’s therapy was adopted by nearly all the best French dentists of that century and the one that followed. The granuloma and apical abscess that would develop later had not yet been connected with pulp necrosis. In many cases, due to fistulization the definitive extraction of replanted teeth was postponed at length.

In Chirurgia, Gabriel Fallopius6 (1523–62), an anatomist in Padua, asserted that if a dental element is lost or falls, or is extracted for therapeutic reasons, the tooth must be healed and then put back in its original site, and fixed to the adjacent teeth with gold or metal wire ligature. If the tooth is not recoverable for whatever reason, another one should be made, reproducing the original shape as closely as possible, and inserted into the socket. The material recommended for this type of treatment is ivory. It is important to note that this seems to be theoretical rather than practical advice. Indeed, there is no clinical evidence in the literature of the period and dentistry continued to be practiced by empirics or mountebanks with results that were almost always disastrous (11).

The 1700s

Around the middle of the 18th century the work of Pierre Fauchard, considered the founder of modern dentistry, began to make a name for itself.7 In his seminal work Le Chirurgien Dentiste, ou traité des dents he described five replantation cases and one transplant. Regarding the latter, he wrote: “The transplant was performed on a captain who, as his left canine was causing him great pain, asked me if it was possible to remove it and replace it with a tooth extracted from another person. Having received an affirmative answer, he promptly had someone call in one of his company’s soldier, who had been advised in advance but whose canine was too large.” Lacking anything better to use and being a military surgeon at the time, Fauchard extracted the tooth anyway and transplanted it after filing it down. The account continues: “Upon seeing him again eight years later, the captain assured me that the transplanted tooth had lasted six years, until the decay had completely destroyed the crown; he told me that the root had been extracted by another dentist, and not without acute pain.” The decay in the crown of the transplanted canine was probably induced by the filing, which had removed the enamel.

Fauchard added that “a small-town colleague whose name he could not recall” had suggested a special transplant technique, consisting of making some notches on the root of the extracted tooth so that, after the transplant, it would consolidate into the new socket. “By squeezing the root on all sides, [the socket] would insert its excrescences in the indentations” so that, “encrusted in this manner, it could last for a considerable amount of time.” These transplants made from a “donor” to a “recipient” became very widespread in Paris in Fauchard’s century, during which “rich patients bought poor people’s teeth.”

Another description by Fauchard is worth reporting.

On April 10, 1725 the daughter of Mr. Tribuot, purveyor to the King, came to me. She was tormented by violent pain caused by decay of the first upper small molar on the right side.8 The girl wished to have the tooth extracted to be released from her pain, but she was hesitant, fearing disfigurement. Thus, she asked me if tooth replantation was possible, as I had previously done with her younger sister. I replied that it would be easy if, during extraction, the tooth did not break, the alveolus did not chip and the gum did not become lacerated. In the end, she decided to do it. I extracted the tooth very carefully. It did not break, nor did the alveolus or the gum become lacerated; therefore, I was able to place the decayed tooth back into its alveolus and tie it to the adjacent teeth with ordinary thread. I kept it tied for a few days, until it definitively stabilized. . . . To extend its life, I sealed the decayed cavity.

Stimulated by the scientific innovation launched by Fauchard, in Europe other authors began to examine the same issues. Louis Fleury Lecluse (1754), inventor of the root elevator for third-molar extraction that was named after him and is still very useful, stated that he had performed about 300 replantations and that many of them were pulpitic teeth. After extraction and healing, he filled the teeth with lead and put them back in the sockets, asserting that after only eight days they regained their normal function (15).

Nicholas Dubois de Chemant (1797), dentist to Louis XIV, stated that he favored this therapy for pulpitic pain. Heinrich Callisen (16), who was very favorable to replants, wrote that he had successfully performed the simultaneous replantation of all the upper frontal teeth of a lieutenant who had lost them during the siege of Copenhagen. He specified that replantations could be performed only with monoradicular teeth. At the same time, however, the Englishman Thomas Berdmore, dentist to the Royal Family of George III, was quite skeptical about the real usefulness of replantations (17).

John Hunter, author of The Natural History of the Human Teeth, published at the end of 1771, believed that it was possible to extract teeth and boil them in order to “destroy their vitality” so that, once dead, they could have no harmful effects and could then be replanted to become one with the maxillary bone. He also performed the famous experiment of transplanting a human tooth with an open apex into a cock’s comb, later demonstrating with an anatomical exhibit—exceptional for the era—that the vascular tissues of the receiving animal had grown inside the pulp cavity of the tooth, which had stabilized there and subsequently erupted (18). Toward the end of the 18th century, dentistry numbered the invention of artificial teeth among its main achievements, and this would prove to be of great importance for the future development of implantology (19).

Several authors dealt with this area and, indeed, as already noted, the preparation and replacement of a human tooth with an artificial one was attempted a number of times over the centuries. Various materials were used to manufacture the replacements: the bones and teeth of cows, horses, rams, deer and other animals; mother-of-pearl; ivory; and hippopotamus, whale and walrus teeth. All surgeons/dentists believed that such materials had aesthetic characteristics coupled with an organic mineral composition that could prevent salivary stagnation, and functional qualities to allow normal chewing and phonetic clarity. It gradually became clear, however, that such therapeutic measures were fallacious: cow bone did not satisfy aesthetic requirements and proved to be porous, tending to yellow; cow and horse teeth had a very different color from that of humans; ivory lacked enamel and tended to decompose. Hippopotamus teeth were preferred and used, as were the rarer whale and walrus teeth, not only because they had enamel, but also because—once filed—they could easily be adapted to human tooth morphology.

Human tooth replantation merits separate discussion. Apart from moral or religious issues, whereby the use of teeth taken from the dead was considered profanation and an insult to the memory of the departed, this practice was not universally accepted due to the serious septic complications for the individual in whom the teeth were implanted, even after appropriate treatment and disinfection.9

Nevertheless, it is clear that, regardless of the type of animal tooth employed, all showed more or less the same drawbacks, such as permeability, the tendency to soften and decompose, sudden color changes, and a terrible stench.

In 1764 Alexis Duchateau made porcelain dentures, but they proved to be very fragile; in 1766 Dubois De Chemant then perfected the material by modifying its composition. Nonetheless, these represented attempts at placing multiple elements at the same time (18, 19).

The 1800s

It was in 1806 that Giuseppangelo Fonzi (1768–1840) (20) invented the mineral tooth, a discovery that would be of great importance for the future evolution of implant dentistry. His greatest achievement was the idea of manufacturing single artificial teeth that could be implanted directly into the socket using platinum hooks, fulfilled important aesthetic and functional requirements, and were also chemically unalterable.10

In the wake of Fonzi’s work, during the 19th century other attempts were made, including the creation of what can be referred to as the first attempt at an endosseous metal implant.

This was designed and placed in a fresh human extraction socket by the Italian Maggiolo in 1809. Considered French because he practiced in Paris and published his book in Nancy, Maggiolo was actually from Chiavari, in the region of Liguria. He graduated in medicine in Genoa and moved to France during the period of the Cisalpine Republic. Since his metal implant anticipates many modern concepts, it is interesting to review the passage in which he discussed the concept in his book, Le Manuel de l’Art du Dentiste (Figs. 27, 28) (21).

Fig. 27. The original cover of Maggiolo’s treatise (1809).

Fig. 27

The original cover of Maggiolo’s treatise (1809).

Fig. 28. Maggiolo’s diagram for manufacturing dental prostheses and the endosseous implant.

Fig. 28

Maggiolo’s diagram for manufacturing dental prostheses and the endosseous implant.

It often happens that the gold posts securing the artificial teeth to the natural roots remain locked in the bone even after they are worn out, acting as partial anchors. Therefore, before splinting the artificial crowns to more stable teeth or extracting them, the attempt could be made to replace the posts with roots made of the same metal, so that they can become stable within the sockets while retaining the artificial crowns firmly, as if they were placed on natural roots.

The procedure is feasible whenever an old root is still fully inside its alveolus, emerging from it by no more than half of its length and only if the socket has all of its natural retention capacity. . . . If conditions are such that success is plausible, then one must manufacture an artificial metal root proportionate to the opening left by the root to be replaced.

The dentist should thus have available a series of artificial roots, in the various sizes of the roots of incisors, canines and bicuspids, which are the only teeth whose sockets permit the procedure to be performed.

What follows is a description of their manufacturing technique (Figs. 29, 30).

Fig. 29. Original diagram for manufacturing the endosseous implant.

Fig. 29

Original diagram for manufacturing the endosseous implant.

Fig. 30. Gold casting made according to the original diagram for the modern reproduction of this artifact.

Fig. 30

Gold casting made according to the original diagram for the modern reproduction of this artifact.

The first piece (no. 11), which we will call the root body, is a long thin gold tube whose diameter and height correspond to the various alveolus dimensions of the roots to be replaced. One of the tube ends must be enlarged by hammering a thin tapered mandrel into it. A lateral opening, similar to the one designed for my snap teeth, described previously, is then cut on this side of the tube (or body).11

A gold plate must be prepared, an oval with the same shape as the horizontal section of the natural tooth to be replaced, and a hole the diameter of the larger end of the tube must be made in the center. The two pieces (nos. 11 and 12) are then soldered together so that the plate hole exactly matches the larger end of the tube and one of its ends is positioned over the notch on the tube. Its two ends must be curved slightly to fit the margins of the alveolus opening as precisely as possible. Then a second small gold tube must be prepared, with a diameter similar to the one of the opposite and thinner end of the tube. It must be cut into four sections, being sure to keep its upper extremity intact, as this will bring the four sections together into a sort of ring.

The four wings are then reduced and separated from each other with a file. At this point, they will be curved to form a sphere resembling the one shown in drawing no. 13. The small sphere must now be inserted onto the thinner end of the tube, so that two thin wings correspond to the larger ends of the elliptic plate and the other two to the smaller ends (21).

The author specifies that the four wings of his small sphere must be placed so that two of them are oriented according to the long axis of the elliptic plate and the remaining two toward the short one, in order to adapt them roughly to the apical third of the root being replaced.

The ring connecting the four wings must then be soldered to the thinner tube section. The ends of three thin wings will also be soldered halfway on the tube; further ahead I will explain why the fourth plate is not soldered like the others. The three pieces, which—once soldered—will give the implant its shape, must be made of 18K gold, not only because this alloy is solid enough, but also because does not cause any problems and remains inside the alveolus (Figs. 31, 32).

Fig. 31. Schematic drawing of Maggiolo’s implant placed in the post-extraction socket.

Fig. 31

Schematic drawing of Maggiolo’s implant placed in the post-extraction socket.

Fig. 32. The principle of “osseointegration” according to Maggiolo.

Fig. 32

The principle of “osseointegration” according to Maggiolo.

Maggiolo deduced this because, in his opinion, “the gold posts of artificial teeth could harmlessly remain the sockets even after complete resorption of the natural roots.” His explanation continues in detail.

Now that our artificial root is ready, we will prepare the site for its insertion. The old root must be extracted. Since damage to the socket walls must absolutely be avoided, it will be firstly divided into three pieces, using forceps with sharp beaks, suitable for its longitudinal separation. One beak must be introduced into the root canal, forcing the other one from the outside, perpendicular to its axis. Firmly snapping the forceps will split the root up to the apex. The pieces will then be removed with watchmaker’s pliers and extracted with gentle and gradual movements, without injuring the gum or fracturing the socket. The procedure will require a few minutes of patience, but this is of little importance when the dentist’s objective is to succeed. In fact, it is advisable to avoid haste when extracting teeth or roots.12 After the root has been removed (and the patient has rinsed his mouth with solution of equal parts water and vinegar), the artificial root must be inserted into the empty socket very carefully. Its base, formed by the oval plate, must be pushed below the gum, which will quickly shift above it. Attention should be paid to ensure that the notch on the larger portion of the tube is rotated toward the inside of the mouth.13 The artificial root will then be forced into the socket until it reaches the bottom. Positioning the thumb toward the index finger, placed in the oral cavity, gradually but firmly compress the socket walls against the metal root. The compressions must be repeated for two-three weeks. The patient should be advised not to displace the artificial root; he must rinse with astringent alcohol solutions while the artificial root gradually becomes fixed in the alveolus.

Numerous examinations have demonstrated that, after extraction, the alveolus walls do not preserve the central cavity for a long time, but progressively close it as they move toward each other.

My artificial root is stable for several reasons. If the alveolus walls have not been fractured during extraction, it is easy to see why, during healing, they will facilitate its fixation inside the newly formed bone.

Furthermore, since the artificial root is thin below the oval plate and consists only of the smooth portion of the tube and the small sphere, the alveolar bone walls can converge and close around the root, increasing its stability, so that the only way to remove it later will be by fracturing the socket.

I already mentioned that one of the four sphere wings should not be soldered to the tube like the others. Sometimes, in fact, the sphere can be slightly larger than the alveolar cavity, preventing the artificial root from reaching the bottom of the alveolus and making it less stable. However, our compression of the alveolus forces the free wing against the bone wall like a spring, thus providing further fixation, a crucial condition for the success of the procedure. The artificial root proves to have achieved sufficient stability when, gently pressing on its outer surface, it does not move even when the pressure is applied to the gum. This proves that the alveolus is stabilizing it permanently. It is not a good idea to immediately insert the snap tooth, which should not be fitted to the artificial root until it has achieved maximum stability; otherwise, all of our good work will have been vain.

Therefore, I recommend that the snap tooth not be inserted until another month has elapsed from the time complete fixation of the artificial root has been ascertained, so that it (the tooth) cannot alter the stability of the root.

This procedure does not cause any problems because the healing tissues can easily enter through the metal vents.

The procedure can be considered one of the finest examples of dental art, because it has such important advantages that, for some time now, I have never failed to consider the option of employing it. I have almost always achieved very satisfying results, both for the persons I have treated and for myself.

This is the report of the first endosseous metal implant, translated from the book written by Maggiolo, “inventor”—as he defines himself—and doctor of surgery of the University of Genoa, and also Member of the Medical Society of Lyon (Figs. 3335).

Fig. 33. Reproduction of the implant.

Fig. 33

Reproduction of the implant.

Fig. 34. Another close-up.

Fig. 34

Another close-up.

Fig. 35. Original drawings of the artificial tooth for insertion into the implant (1809).

Fig. 35

Original drawings of the artificial tooth for insertion into the implant (1809).

The Maggiolo implant was also cited 36 years later in William Roger’s Encyclopédie du Dentiste (1845). Roger warns that the “Maggiolo experiments” must be monitored constantly and cleaned frequently with disinfectant mouthwash “because they cause teeth mobility, a bad smell and pain.” He also mentioned the case of a patient who, despite such precautions, “couldn’t wait to have the artificial root removed, as it was real torture!”

Roger’s criticism notwithstanding, Maggiolo’s “artificial root” represents the first metal implant used to replace lost human teeth. His implant precedes ours by nearly two centuries and, despite the limited surgical possibilities of the time, the lack of anesthetics and antibiotics, and the complete lack of occlusal knowledge, it essentially encompasses many of the concepts that developed during our era and are wrongfully considered the exclusive and original brainchild of some of our contemporary colleagues.

In fact, Maggiolo’s artificial root prefigures:

  1. the principle of osseointegration by new bone apposition through and above the empty spaces of vented structures made of metal;
  2. the principle of reparative osteogenesis protection by the “two-step submerged implant” technique;
  3. the search for primary stability as the sine qua non condition for osteogenesis.

It had limited success due to a combination of the following concomitant factors:

  1. the non-biocompatibility of the 18K gold alloy, containing cytotoxic materials such as copper, and the even more cytotoxic alloy employed for soldering;
  2. the lack of effective anesthetics, antiseptics and anti-inflammatory agents;
  3. the fact that it was impossible to conduct radiographic checkups of the sockets, any wall fractures and/or the possible presence of apical granulomas (the roots to be extracted, discussed by Maggiolo, had never been treated with appropriate root canals!);
  4. the limited availability of properly shaped metal structures fitted for the sockets.

In the United States, dentists—who since the 19th century had been at the forefront of dental science—conducted numerous implant attempts and experiments.

Around the 1840s Chapin A. Harris and Horace H. Hayden, founders of the Baltimore College of Dental Surgery (1840), attempted endosseous implants employing iron teeth of their own design (18).

Harris, in particular, was the first to place a lead-coated platinum post in an artificial socket “to resemble the root of a natural tooth.” Harris had also roughened the lead in order to provide the retention for the “new” tissue that was supposed to form inside the artificial cavity. After removing the ligature used for temporary splinting to the adjacent teeth, he placed a porcelain crown on that implant, an operation that—in his opinion—was successful.

Today we know that lead is not biocompatible. Reactive and inflamed hypertrophic tissue must have formed around that implant, giving the illusion of temporary stability.

Three similar implants (placed in surgically prepared sockets) were also performed by Perry and Edward (1888 and 1889), and reportedly were equally successful.

Slightly different implants, also lead-coated, were performed by Edmunds in New York. He reported that on October 21, 1886, he had “implanted” a platinum “capsule” coated with lead and roughened with a drill. Four years later, on March 12, 1889, he performed a similar operation at the dental clinic of the First District Dental Society of the State of New York during the Society’s annual congress. It is interesting to note that during the same year he worked on his colleague Juan Josef Ross, from Guatemala, placing one of these implants in an artificial socket made near an upper incisor that have fallen out years earlier. He reported that four days later Dr. V.H. Jackson, who had attended the surgery, had ascertained that the artificial tooth “was still in place and showed remarkable stability, with no apparent irritation of the surrounding tissues.”

Lead is, in fact, a much more cytotoxic element than the 18K gold employed by Maggiolo. The choice of lead as coating material for the internal platinum frameworks was probably due to the fact that it is easy to use. In fact, it can be melted (327.46°C) and poured into cavities similar to those made by drilling the edentulous ridges. Moreover, before it hardens completely, the internal platinum framework can be easily immersed in it. It is also very easy to roughen, modify and adapt in the event of emergencies (22).

Harris, Perry, Edward and Edmunds may have employed lead because it cannot be attacked by some of the most corrosive acids, failing to consider its high toxicity. Indeed, it is a tricky and powerful poison that has been known to cause intoxication since antiquity. Hippocrates identified it as what had poisoned a galena miner; Pliny the Elder described its toxic effects on slaves forced to do the same work. Even when lead was being tested as an implant material, the effects of saturnism in workers who had daily contact with the element (such as typesetters) were well known.

In the same year in which Edmunds inserted his first lead-coated platinum capsule (1896), Lewis implanted a porcelain tooth with an internal gold support, thus assuring of a successful outcome as well! Two years later, the German Znamensky described some of his experiments with endosseous implants made of “carved porcelain,” rubber and gutta-percha.

In March 1895, William Bonwill reported to the First District of the Dental Society of the State of New York that he had successfully implanted pierced tubes as well as solid gold and iridium posts in artificial sockets, used “to replace individual teeth and restore full dental arches.” Bonwill’s implants represent a step forward in the evolution of such attempts, because he used pure materials such as 24K gold and iridium, which are virtually incorruptible, and employed them not only to replace individual teeth, but also to add artificial abutments to multiple tooth prostheses. Bonwill’s technique was also adopted by Gramm, who likewise used solid pierced cylindrical implants made of 24K gold and/or iridium.

In the implantology field, Payne is the last author of the 19th century and the first of the 20th. He used silver “capsules”14 and gave a practical demonstration at the 1908 American Dental Association Congress.

Accepting the validity of Payne’s silver capsules is difficult, but since he gave other public demonstrations of the method three years later, we can assume that, at least for a while, the implants and porcelain structures showed sufficient stability.

Although these cases cannot be considered full-fledged success stories, it must be stressed that during this century, figures from Maggiolo to Payne progressively attempted—at least on a conceptual level—to use increasingly “inert” materials, and this was paralleled by the development of the concept of inserting alloplastic roots with a retentive morphology.

Other attempts were made by several authors. In 1870 Rogers tried to place metal implants in the jaw; in 1888 Lewis made and used a platinum root-shaped implant with a porcelain crown, following impression taking of the alveolar cavity with a plaster-based material.

In 1890 Léopold Ollier proposed platinum and nickel-plated steel screws as an osteosynthesis means, but it remained an isolated experiment whose application was more useful for orthopedics and traumatology than it was for dentistry.

In 1891 Wright designed a porcelain tooth with a porous root in order to facilitate its fixation within the socket. On the basis of this experiment, the following year Friel replicated the model, providing the root with a certain number of holes connected to each other by a central channel that opened at the crown to facilitate drainage in the event of an apical abscess (18, 23).

The 1900s

The early 20th century was marked not only by Payne’s renewed attempts to employ his silver vented cylinders, but also Sholl’s first porcelain roots, “roughened” in order to increase retention. While not as biocompatible as studies would attempt to demonstrate even 70 years later,15 porcelain was nevertheless a better material than the ones proposed previously.

The first artificial porcelain root, inserted in August 1903, was checked in November of the following year and showed good stability. Nevertheless, it is important to note that the artificial crown placed on the implant had been blocked with two splintings to the crowns of the adjacent teeth.16

This brings us to E. J. Greenfield’s “two-step” cages (1913), which anticipate the evolution of modern implantology, despite their flaws (Figs. 3640) (24, 25).

Fig. 36. Original drawing of the Greenfield drill for the endosseous basket (1913).

Fig. 36

Original drawing of the Greenfield drill for the endosseous basket (1913).

Fig. 37. X-ray of a Greenfield basket, which is perfectly osseointegrated.

Fig. 37

X-ray of a Greenfield basket, which is perfectly osseointegrated.

Fig. 38. Magnified view of the basket.

Fig. 38

Magnified view of the basket.

Fig. 39. Greenfield’s prosthetic technique.

Fig. 39

Greenfield’s prosthetic technique.

Fig. 40. The surgical cut made with a Greenfield drill implicated leaving the central bone core (original drawing).

Fig. 40

The surgical cut made with a Greenfield drill implicated leaving the central bone core (original drawing).

Casto in 1914 and Kauffer in 1915 placed spiral-shaped implants, both stating that they were satisfied with the outcomes.

After World War I, the Frenchman H. Léger-Dorez (1920) designed a “tubular extension” implant (Fig. 41) that was conceptually similar to the modern expandable screw in its forced anchoring into the bone. With this kind of mechanical compression, he believed he had designed an important innovation, as he thought that his implants could be stabilized immediately, even before “biological” encapsulation through reparative osteogenesis.

Fig. 41. The Léger-Dorez implant (1920).

Fig. 41

The Léger-Dorez implant (1920).

The materials for his four-piece “tubular extension” implant were made of 24K gold for the body and platinum for the internal expandable screw. As we will see later, the failure of those implants (and similar ones that we will examine) lay precisely in mechanical expansion, which was rigid and forced beyond the endurance of living bone tissue.

That year, Weigele placed a frustum-shaped piece of ivory into artificial sockets, protected by mucosa sutured over it; the ivory should have promoted a slow resorption reaction by ankylosis, one that would allow the temporary load of a post crown to be inserted subsequently. Years later, Weigele reported that he had used his ivory cones as endosseous overstructure supports for the temporary anchorage of lower complete dentures. Concerning this method, which is limited time-wise by the inevitable rejection of ivory by human bone, we must emphasize the important principle of the “two-step submerged” implant, anticipated by Maggiolo a century earlier, followed by Greenfield (1913) and Alvin Strock (1933) in the first half of the 20th century.

In the attempt to create solid and resistant inclusions coated with materials he believed were inert, Abel (1934) used Vipla vitrified steel and “reticulated” platinum cylinders coated in porcelain.

With the same hope of finding—at last—the ideal biocompatible material, Wuhrman (1937) used vented platinum structures, assuming that it was inert, given that it was a pure element with a high molecular weight. The idea was brilliant, but unsuccessful.

In 1938 the U.S. patent office granted P.B. Adams exclusivity for a “two-step” implant for the “spherical” anchorage of removable prostheses (“Anchoring means for false teeth”). The implant had no luck but, re-examined today, it closely resembles the osseointegrated implants presented by the Swede Per-Ingvar Brånemark 40 years later (Figs. 42, 43).

Fig. 42. P. B. Adam’s original drawings for the patent of his implant system (1938).

Fig. 42

P. B. Adam’s original drawings for the patent of his implant system (1938).

Fig. 43. This prosthetic anchorage technique has changed very little in 70 years.

Fig. 43

This prosthetic anchorage technique has changed very little in 70 years.

Why did the implant fail? The main reason resides in extremely low biocompatibility of the materials that were employed, coupled with the lack of practical clinical demonstrations.

In 1938 Gustav Dahl, also Swedish, attempted a subperiostal mandibular implant, inserting four metal posts on which he later anchored a prosthesis.

It is important to note that, after this attempt, the Swedish Dental Society asked him to refrain immediately from performing the treatment—the penalty being expulsion from the society—just when the procedure seemed destined for success (26).

In 1939, in Boston the Strock brothers began human testing with screws made of Vitallium, a chromium-molybdenum-cobalt alloy that they had already tested on dogs.

Their scientific reports about their experiments were characterized by modesty, prudence and elegance, and despite the fact that they represent yet another milestone in the evolution of implantology, they remained virtually unknown and were mistaken for the many failures of other methods (Figs. 4451) (2729).

Fig. 44. Alvin Strock and Marco E. Pasqualini in 1985.

Fig. 44

Alvin Strock and Marco E. Pasqualini in 1985.

Fig. 45. A copy of the original publication on Strock’s two-step submerged implant, with a dedication to Ugo Pasqualini.

Fig. 45

A copy of the original publication on Strock’s two-step submerged implant, with a dedication to Ugo Pasqualini.

Fig. 46. Strock’s two implant morphologies; they are submerged implants (1948!).

Fig. 46

Strock’s two implant morphologies; they are submerged implants (1948!).

Fig. 47. Original pictures and radiographs of a Strock submerged implant that is perfectly integrated (1948).

Fig. 47

Original pictures and radiographs of a Strock submerged implant that is perfectly integrated (1948).

Fig. 48. Detail: agenesis of the lateral left upper incisor (original).

Fig. 48

Detail: agenesis of the lateral left upper incisor (original).

Figs. 49, 50. X-ray magnifications (original).

Figs. 49, 50

X-ray magnifications (original).

Fig. 51. Strock’s threaded screw.

Fig. 51

Strock’s threaded screw. Left: the screw immediately after placement in a post-extraction socket. Right: complete healing of the bone is visible at three months.

In 1941 Glenn D. Irwin again proposed a post-extractive “rapid-expansion” implant that, like the previous one devised by Léger-Dorez, did not have much success.

The following year Gunhtert used gold-palladium-silver alloy implants, citing that they offered high resistance to fracture, great elasticity (which he considered useful in adsorbing occlusal loads) and the absence of reactivity with the host tissue.

In the 1940s Jean Lehmans successfully placed some very original implants, which he named “expandable arch” implants, demonstrating their positive outcomes radiographically; these implants could also be placed in thin edentulous ridges (Figs. 5254) (30). His implants, made of tantalum—whose biocompatibility had already been demonstrated in orthopedics—for the first time, were composed of a threaded pin with a thin elastic circular band inserted into it and kept in place by two nuts (also threaded), respectively in its “apical” and “occlusal” portions. When turned, the two nuts could extend the band toward the bone groove ends in which the implant had previously been placed. Therefore, it was locked even before secondary stability occurred due to closure of the groove through reparative osteogenesis. The elastic pressure of Lehmans’s expandable arch was enough to stabilize the implant without causing ischemia beyond the bone’s reactive capabilities.

Fig. 52. Lehmans’s original drawing.

Fig. 52

Lehmans’s original drawing.

Fig. 53. 53 Examples of Lehmans’s endosseous implants.

Fig. 53

53 Examples of Lehmans’s endosseous implants.

Fig. 54. X-ray of an arch implant (1959).

Fig. 54

X-ray of an arch implant (1959).

In the history of implantology, this represents the first attempt to use a bone groove in place of a cylindrical bore. The groove was created by a series of thin vertical tunnels that were then connected by mean of a fissure bur. High-speed drills did not exist at the time and, consequently, these steps were mandatory. Nevertheless, Lehmans’s implant was not very successful, although the author proposed it again a number of times after the middle of the century: in 1959, 1960 and 1961 (30).

In 1946 Meylan also patented a more complicated “wire spring” implant that exploited the elastic pressure of two steel looped wires placed in a large artificial alveolar cavity, where they were spread by the progressive screwing of two bolts.

Other experiments were also made by immersing artificial roots in thermosetting or self-curing acrylic resin. The following tests were performed:

  1. inclusions of roots made of thermosetting resin, manufactured from the impression of fresh extraction sockets, by Charad-Nur, (1948) and Rossi (1949);
  2. inclusions of self-curing resin, placed while still in a soft state in surgically undercut sockets, by Kelly and Rottemberg (1948). After the self-curing resin had been pressed into the cavities and undercuts, but before it hardened, a post was inserted in the cavity for the future artificial crown, or the crown was fitted with a retentive post, which rapidly became one with the self-curing resin placed there a few seconds earlier. The unavoidable overheating produced by resin polymerization was compensated—at least in theory—by a water-cooling jet.

These authors were not the only ones who, attracted by the novelty of the plastics that had already been used experimentally in ophthalmology and orthopedics, attempted to perform such procedures. Nonetheless, since similar attempts continued in the second half of the century, they will be discussed ahead.

In 1946 Norman Goldberg and Aaron Gerschkoff proposed Vitallium juxta-osseous implants, intended mainly for use in the lower jaw; they were set on the mandibular ridge and kept in place by screws (Figs. 5571) (31, 32).

Fig. 55. Severe periodontitis in a 29-year-old woman.

Fig. 55

Severe periodontitis in a 29-year-old woman. After complete edentulation and healing, Luigi Marziani of Rome placed two total subperiosteal implants (1955).

Fig. 56. The inferior implant made of tantalum.

Fig. 56

The inferior implant made of tantalum.

Fig. 57. Preparation of one of the two mesh plates.

Fig. 57

Preparation of one of the two mesh plates.

Fig. 58. Latero-lateral X-ray of the two mesh plates inserted.

Fig. 58

Latero-lateral X-ray of the two mesh plates inserted.

Fig. 59. Frontal X-ray.

Fig. 59

Frontal X-ray.

Fig. 60. Patient’s profile before and after.

Fig. 60

Patient’s profile before and after.

Fig. 61. Appearance of the mucosae before insertion of the Dolder bars on the threaded abutments of the implants.

Fig. 61

Appearance of the mucosae before insertion of the Dolder bars on the threaded abutments of the implants.

Fig. 62. Close-up of the healed soft tissues.

Fig. 62

Close-up of the healed soft tissues.

Fig. 63. Placement of the prosthetic splinting bars.

Fig. 63

Placement of the prosthetic splinting bars.

Fig. 64. The two definitive overdentures (1955).

Fig. 64

The two definitive overdentures (1955).

Fig. 65. The same patient 52 years later!

Fig. 65

The same patient 52 years later!

Fig. 66. Upper denture in place of the subperiosteal implant, which was removed in 1997 due to oroantral communication after 42 years of service.

Fig. 66

Upper denture in place of the subperiosteal implant, which was removed in 1997 due to oroantral communication after 42 years of service.

Fig. 67. Healing and healthy appearance of the palatal mucosa.

Fig. 67

Healing and healthy appearance of the palatal mucosa.

Fig. 68. Lower overdenture still working with the subperiosteal implant (2007).

Fig. 68

Lower overdenture still working with the subperiosteal implant (2007).

Fig. 69. Dehiscence of the tantalum implant placed in 1955, without any complications for the patient.

Fig. 69

Dehiscence of the tantalum implant placed in 1955, without any complications for the patient.

Fig. 70. Bar and dehiscence (2007).

Fig. 70

Bar and dehiscence (2007).

Fig. 71. The prosthesis with latch attachments still in service after 52 years!

Fig. 71

The prosthesis with latch attachments still in service after 52 years!

The year 1947 is historical, as it marks the birth of modern implantology. On February 27 of that year, at a conference held at the AMDI (Italian Dental Association) in Milan, the Italian Manlio Formiggini proposed the hollow spiral screw in stainless-steel wire or tantalum, a white-silver material whose technical use could be veritable torture. Its designer named the method “direct endoalveolar infibulation” and it marked the definitive transition to the era of endosseous implants (Figs. 72, 73) (33).

Fig. 72. One of Formiggini’s first screws (1947).

Fig. 72

One of Formiggini’s first screws (1947).

Fig. 73. Close-up of the Formiggini spiral.

Fig. 73

Close-up of the Formiggini spiral.

The screw I designed for intramaxillary infibulation is manufactured with a wire made of unalterable material, with a thickness of 1–1.2 mm, bent to form a spiral around a central axis that stabilizes the system. The central axis is fixed at the apex of the spiral because it forms its extension, whereas at the base it is soldered to the free end of the spiral, thus allowing the forced screwing of the implant into the anatomical or surgical socket. Therefore, my designation of ‘hollow screw’ seems justified, as the screw pitch is, so to speak, free and suspended, but stabilized by the central shaft (33).

It would be interesting and, indeed, crucial for the historical knowledge of implantology to quote the whole report that Formiggini gave in Stresa in 1952, when he presented several clinical cases and brought with him two patients who chewed—problem-free—with fixed prostheses cemented on his “infibulations.”

Before starting my speech, I would like to thank the Board of Directors of the Dental Association for giving me the honor of presenting the results of my studies in a field where other scientists already made several attempts, always with negative results.17

The replacement of permanent teeth that have been lost following trauma or expulsive diseases, or have been surgically removed has long been the dream of patients and stomatologists. And now, if I weren’t afraid of being overly modest, I would say that, with the method I am going to present, I am confident that I have fulfilled this aspiration.

For the idea of designing my system, I can thank the negligence of a client whose upper canine I extracted due to periodontitis and a periapical abscess. After extraction, I inserted an iodoform pledget into the socket, advising him to keep it in place and come back the following day to have it removed. He instead returned two months later, swearing that the drainage was still in place! This seemed odd to me and I checked it carefully: the oral mucosa was absolutely normal and the access to the alveolar cavity appeared to have closed almost entirely by then. After inserting a probe with some difficulty, I felt the pledget, which I promptly removed. The extraction was difficult, painful and bloody, because connective tissue had grown between the iodoform gauze meshes, fixing it to the socket wall. I was surprised by the fact that the gauze had not been expelled as a foreign body and had not caused inflammatory reactions.

At this point, I thought that the gauze could be replaced with a similar but unalterable material. Therefore, I prepared a small roll of steel wire netting, which I experimentally introduced into the fresh socket of another patient. The result was negative, because the small roll was soon expelled. Consequently, I understood that it was not simply a matter of introducing a foreign body into the socket, but of keeping it in place at all cost.

With that in mind, in place of the small roll I designed a stainless-steel wire screw (which could be also made of other unalterable metals, preferably tantalum—if it weren’t so expensive [in Italy]).

My screw can be manufactured in two ways: with a sturdy wire with a diameter of about 1.8 mm, rolled into a slightly conical spiral and ending at the base with a short straight portion parallel to the axis of the cone, or with a thinner wire with a diameter of 1.2 mm, shaped like the previous one but with the addition of a central axis made of the same wire that, starting at the apex of the spiral, extends to the opposite end, where it should then be connected using a spot welder or, better yet, ordinary soldering. For fixation and elasticity reasons, I choose the latter type of spiral and I started experimenting on an old man from a nursing home in Modena, from whom I requested the utmost confidentiality.

Unfortunately, this happened toward the end of 1943, when I was suddenly forced to leave Modena because I had been issued a double arrest warrant.18 I fled to nearby Bologna under the assumed name of Manfredotti, and for 17 months I organized and directed the health services of the local partisans. In the meantime, my office was invaded by the armed forces of the Italian Social Republic, who also confiscated the notes I had gathered on the subject, along with my professional material.

When I returned after the liberation, that first patient of mine had died along with his secret. At that point, and with far greater peace of mind, I resumed my studies.

Today I present myself to you, dear Colleagues, with this introductory note and my report on three successful cases. Before illustrating them to you, I would briefly like to discuss the surgical technique for this type of implant.

It can be placed in fresh and artificial sockets alike, as a support both for single crowns and prosthetic devices.

Before inserting the screw into the artificial or natural socket that will host it, it must be flame-sterilized without heating it to red hot and must then soaked in iodoform powder, which the heat will melt to form a superficial layer of antiseptic varnish. The screw must then be inserted in the socket by screwing it forcefully, as you would with an ordinary screw, until all you can see on the surface are the straight ends, which are welded together and designed to act as the bearing post for the future prosthesis.

Obviously, when extracting the tooth to be replaced with my system, it is advisable to measure the thickness and length of its root with a compass and a probe, in order to obtain a reference in choosing the implant, which must be slightly larger, because it is essential that it create its own accommodation within the corresponding socket walls.

It should be borne in mind that the screw or, rather, the spiral must be inserted deeply, until it is completely contained within the socket cavity. On the outside, the two ends forming the central shaft are all that will protrude, but only in part. The procedure is different when an artificial socket needs to be prepared.

Following anesthesia, a small incision is made in the soft tissues up to the periosteum. A cavity resembling a socket must then be made in the bone, initially using a round bur and subsequently widening the bore with a commercially available drill, the type the French call a couteau de Rollins.19 All that remains to be done at this point is insert the selected screw promptly, following the same procedures employed for the previous case.

I have never observed the slightest inflammatory reaction with my procedures, although a few days after placement the screw can become slightly mobile. It can be fixed again, screwing it in until it is stable.

You should not expect absolute stability immediately, because it will be achieved later, when granulation tissue has formed between the elements of the spiral. Bone tissue will subsequently obliterate the alveolar cavity.

The best timing for applying the prosthesis is left to the operator’s discretion.

Regarding impression taking, there are no special recommendations. It is performed as done for a common post crown, but to facilitate this operation, the protruding end (the bearing post) can be covered with a small stainless-steel tube, which will be retained in the impression material and subsequently become part of the prosthesis, preferably made of synthetic resin.

Esteemed Colleagues, I would like to ask you to examine the radiographs of three cases I treated using the method I just described. I would have liked to have my patients here with me, but current conditions made this impossible.20 I must also confess that I would also have liked to present statistical data with a larger number of cases but, as I am sure you can easily understand, I could not have expanded my study without running the risk of the information getting out.

Two intraoral films refer to two young patients: the first one is of a certain Z.G., 20 years old, from Castelfranco Emilia and a soccer player, whose central left incisor I extracted on October 31, 1946; I then placed one of my screws on November 22. On January 3 I completed the procedure with a tooth made of synthetic resin. The delay in applying the tooth was due to the fact that the patient had urgent business to attend to and was unable to come. There was no immediate or late inflammatory reaction. The radiograph, taken one month after the screw was inserted, shows a small area of bone resorption due to a previous suppurative process, but also the tendency toward the formation of bone tissue between the screw pitches.

The second radiograph is of a certain V.G., a 22-year-old from Finale Emilia, who on November 13 underwent extraction of the upper left canine, followed a few days later by screw insertion, which was then completed on the 30th of the month with a crown made of synthetic resin. The radiograph, taken just 20 days following infibulation, shows the tendency to encapsulation by the newly formed tissue, although an area of bone rarefaction persists at the alveolar apex, due to a previous periapical abscess. No inflammatory reactions.

Nevertheless, the most demonstrative case is the third one, a certain M.G., a 40-year-old from Cavezzo and a regular client, who was wearing an upper left four-element gold bridge supported by the first premolar and the second molar. Due to septic periodontitis of the second molar and the wisdom tooth, I had to remove the bridge and extract the two distal molars. I considered replacing the distal abutment tooth that I had just extracted with one of my implants, and of the three available alveolar cavities I chose that of the second molar, since its axis was parallel to the front abutment. I then inserted the screw.

Again in this case, as in the previous two, there was no immediate or late inflammatory reaction. The only thing I was forced to do was turn the screw once eight days following insertion, in order to further stabilize it further.

The first radiograph, taken 25 days after surgery, showed that the bone tissue was still rarefied around the screw. Consequently, I felt it best to wait 20 more days before applying a four-element bridge, the anterior of which was a gold crown, whereas the other three, distal, were gold-resin crowns.

The second radiograph, taken 40 days later with the prosthesis in place, shows the crown, the metal prosthesis structure and the screw, around which (and this is the most interesting aspect) we can already observe healthy bone tissue that is invading even the spaces between the screw pitches. This demonstrates that not only did the osteoporotic reaction typically found in the presence of a foreign body fail to occur, but that a reparative process and reossification of the alveolus had already started. From a functional point of view, I can assure you that my patient, like the others, is enthusiastic about the prosthesis and can chew without any pain.

I hope that my simple report and the modest case study will suffice to prove the validity of my method. I am confident that the successful outcome of my first three cases will soon be confirmed by my future experiences as well as yours (Figs. 7480) (34).

Fig. 74. Two Formiggini spirals in service since 1952 and checked in 1981 after other implants were inserted.

Fig. 74

Two Formiggini spirals in service since 1952 and checked in 1981 after other implants were inserted.

Fig. 75. Close-up of the previous image.

Fig. 75

Close-up of the previous image.

Fig. 76. Detail of the X-ray: excellent adhesion of the bone tissue around the spiral (1960).

Fig. 76

Detail of the X-ray: excellent adhesion of the bone tissue around the spiral (1960).

Figs. 77, 78. Formiggini spirals, loaded and unloaded (1958).

Figs. 77, 78

Formiggini spirals, loaded and unloaded (1958).

Fig. 79. Image immediately after placement into the socket.

Fig. 79

Image immediately after placement into the socket.

Fig. 80. An excellent radiographic image of one of Formiggini’s screws, still working perfectly in 1985.

Fig. 80

An excellent radiographic image of one of Formiggini’s screws, still working perfectly in 1985.

Despite the veracity of the concepts it expressed, the report left itself open to criticism from many who were more accustomed to scientific presentations. And this is inevitably what happened!

The dental world was experiencing a justified period of cautious skepticism toward endosseous implants and hope instead lay in the possible success of the very recent technique of subperiosteal implants. As a result, failures (due to technical mistakes made by Formiggini’s first disciples) were given greater consideration than successes when it came to official judgments (35, 36).

This method was later accepted with only a few exceptions, and more so abroad than in Italy. We will also see how the modifications made by his pupils allowed a large number of patients to enjoy the benefits of the implants that originated from his ingenious innovation.

Some of these modifications—above all those made by Carlos Perron Andres—were limited to replacing the two vertical portions of the screw with a single metal portion that was thicker and more rigid (Figs. 81, 82).

Figs. 81, 82. The Perron Andres implant.

Figs. 81, 82

The Perron Andres implant.

At the beginning of the century Perron Andres provided many radiographic demonstrations of the validity of Formiggini’s “hollow spiral,” which the Spaniard improved slightly, though strictly in terms of the solidity of the external prosthetic abutment (37).

The only difference between Formiggini’s original spiral (the two small external portions had to be joined using a spot welder or soldering) and in Perron Andres’s version the two portions were replaced by a single fused block. Nevertheless, over the years this method gradually and definitively became established, gaining widespread consensus, and studies were conducted on the histological reactions of the tissue involved in the implant treatment (Pini, Zepponi, Sordo, Gola, Roccia, Marziani et al.). (38). During the 1950s Blum made a few—but unsuccessful—attempts at using self-curing synthetic resin in the socket, in which the implant was placed before the resin hardened completely. However, the experiments were soon abandoned due to the toxicity of the compound (18).

At this point, we would also like to mention the contribution made by the Dental Clinic of the University of Pavia, as we are currently conducting a historiographical overview to shed light on the many scientific studies conducted over the course of 90 years of activity. The Associazione Europea Odontostomatologica per gli Impianti (European Dental Implant Association) was founded at the University of Pavia in 1955, and experimental and histological studies were conducted here (Palazzi, Borghesio, Branchini, Piazzini, Continolo). Vitallium implants were employed, i.e. the type that had already been used previously; as noted, this alloy is made of cobalt (65%), chromium (30%) and molybdenum (5%) (3941). It was also during the 1950s that Flohr experimented with implants made of steel-reinforced resin screws (42), whereas in 1961 Stefano Tramonte was the first to propose the self-threading screw in chromium-cobalt-molybdenum and chromium-nickel-molybdenum; he was also the first in the world to employ titanium as implant dentistry material (43). The following year Muratori presented “hollow” screws, which represented a further improvement of Formiggini’s screws in terms of shape, structure and surgical technique (44).

In the late 1950s and early 1960s, in France Raphael Cherchève further modified the design of the Formiggini screw (Fig. 83), creating the double-helix implant (45); a similar device, with minor modifications, was also employed by his countryman Max Jeanneret (Fig. 84).

Fig. 83. Different designs of endosseous screws used in the 1960s and 1970s.

Fig. 83

Different designs of endosseous screws used in the 1960s and 1970s. The middle one is the Tramonte screw, currently proposed as an “elective” immediate load implant.

Fig. 84. The Jeanneret implant.

Fig. 84

The Jeanneret implant.

The greatest developments in endosseous implantology took place in the 1970s with the creation of the “blade” (the name used by Linkow) (46) and the “needle” (the name used by Scialom) tantalum implants (4748). In Italy, several authors proposed a number of modifications, such as the “custom universal blades” created by Muratori in 1970 (49) and the “postless polymorphic blade implants” devised by Ugo Pasqualini; (46) in 1975 Pier Luigi Mondani came up with the idea of using intraoral soldering for the needles; in 1974 Dino Garbaccio proposed the bicortical self-threading screw. These authors will be discussed in the chapters that follow.21

In the late 1970s and early 1980s, Brånemark presented the so-called “osseointegrated” implants. According to Brånemark, osseointegration “is the direct structural and functional connection between living bone and the surface of a load-bearing implant.” The method consists of positioning screw-shaped titanium implants with small threads (screws for metal), offering good resistance to torque and able to assure good mechanical elasticity. They have microgrooves that permit integration with the bone tissue, which shapes itself around the implant. Titanium is considered the most biocompatible material, as it can be used in a wet-organic environment; it is made of titanium dioxide (51).

Many of these concepts had already been anticipated by Pasqualini (1962), as we will detail in these chapters (50, 52).


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Pasqualini ME. Un impianto alloplastico in una mandibola di 1300 anni. Ricerca istologica. Dent Cadmos. 2000;11:57–62.


Of the entire Corpus Ippocraticum, the most interesting book in which Hippocrates dealt with dentistry is De Carnibus.


Abdul Quasim al-Zahrawi, latinized as Abulcasis, was one of the first to propose appropriate instrumentation for dental surgery, which he described extensively in his richly illustrated work; many of the drawings were done by the author.


Guy de Chauliac was one of the most important surgeons of the 14th century; a professor at the Saint Esprit Hospital in Montpellier, he was the personal doctor of three Avignon popes.


Falcucci Nicolò. Sermones Medicales. Venice: p. 1507.


Gabriel Fallopius, a pupil of Andreas Vesalius (1514–64), was the first to demonstrate that tooth development starts in the fetal period, and he discovered the dentoalveolar ligament.


Le Chirurgien Dentiste ou traitè des dents, published in 1728, was a milestone for the rise of dentistry and represents the first scientifically structured treatise on this discipline. It analyzes several branches of dentistry: the treatment of caries, surgery, prosthodontics, oral hygiene and orthodontics. It also deals with implants and dental replantations.


The “small molars” were the first and second molars.


The few authors who proposed these methods (Lefoulon, Maury, Dubois De Chermant) asserted that the replanted human tooth had better characteristics than others: higher resistance against the corrosive action of saliva, a better appearance, higher success rates and lower costs.


Fonzi called these artificial elements “terrometallic teeth.” In addition to the mineral pastes in use at the time, they were also composed of substances that gave them particularly high mechanical strength, consistency and hardness. The main substances employed by Fonzi were kaolin, Limoges silicate, zinc oxide, titanium oxide, manganese oxide, gold oxide. Fonzi noted that he was able to create 26 shades of color by using various compounds.


Maggiolo is referring to the first part of his book, describing his new technique of “snap” artificial crowns, which are accurately portrayed in the second series of sketches in Fig. 28.


Maggiolo’s recommendations prove that the surgeons of the early 19th century were already using anesthesia that could guarantee slow enough work time and thus the accuracy of the procedures. Sulfuric ether vapor was already in use and Davy had published his work on the anesthetizing property of nitrous oxide or “laughing gas” nine years earlier.


The “notch” allowed the snapping insertion of the artificial tooth. Since it was rotated toward the mouth, the snapping mechanism was not visible.


Payne’s “capsules” were similar to the vented tubes of Bonwill and Gramm, the only difference being the material: silver in place of 24K gold and/or iridium.


See the results of Pasqualini’s studies on animals, described in Chapter 2.


As temporary stress breakers for long bridges, they used the implants of Sholl and Brill (1926–32–36), as well as those of A. Hurska Jr. (1936), albeit with minor variations.


At the time of his report (right after World War II) Formiggini could not have been aware of the results of the Strock brothers’ studies.


The double arrest warrant for Formiggini was a result of the racial laws against Jews that had just been enacted by Mussolini, who embraced the criminal theory of his German ally. Formiggini’s father, humiliated by the measure, killed himself by jumping from the bell tower of the Cathedral of Modena.


Similar to Ottolenghi’s drills.


For his second report, given five years later at the Italian Dental Congress in Stresa (1952), Formiggini brought in patients wearing implants.


It must be remembered the Swiss Samy Sandhaus who, towards the end of the 1960s studied the one-step and two-step screws in alumina and zirconia called “Cristalline Bone Screw”.

Figs. 69 Courtesy of Prof. Amedeo Bobbio – São Paulo, Brazil.

Fig. 37 Courtesy of Prof. Leonard Linkow – New York, United States.

Figs. 4850 Courtesy of Prof. Alvin Strock – Boston, United States.

Figs. 5571 Courtesy of Dr. Giancarlo Cortese – Turin, Italy.

Figs. 14, 7, 911, 16, 22, 23 taken from Pasqualini ME. Un impianto alloplastico in una mandibola di 1300 anni. Ricerca istologica. Dent Cadmos. 2000;11:57–62.

© copyright 2009 Azienda Pubblica di Servizi alla Persona “Suor Agnese”.

All rights reserved. No part of this book covered by the copyrights hereon may be reproduced, stored, communicated or copied in any form or by any means - graphic, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems - without written consent from Marco E. Pasqualini (tel. +39.02.799651).

Bookshelf ID: NBK409631


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