Long-term implant success at the Academy for Oral Implantology: 8-year follow-up and risk factor analysis

PURPOSE: Rehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy; however, little is known about potential risk factors that may impair long-term implant success. METHODS: From 2004 to 2012, a total of 13,147 implants were placed in 4,316 patients at the Academy for Oral Implantology in Vienna. The survival rates after 8 years of follow-up were computed using the Kaplan-Meier method, and the impact of patient- and implant-related risk factors was assessed. RESULTS: Overall implant survival was 97% and was not associated with implant length (P=0.930), implant diameter (P=0.704), jaw location (P=0.545), implant position (P=0.450), local bone quality (P=0.398), previous bone augmentation surgery (P=0.617), or patient-related factors including osteoporosis (P=0.661), age (P=0.575), or diabetes mellitus (P=0.928). However, smoking increased the risk of implant failure by 3 folds (P<0.001) and a positive history of periodontal disease doubled the failure risk (P=0.001). CONCLUSIONS: Summing up the long-term results of well over 10,000 implants at the Academy for Oral Implantology in Vienna it can be concluded that there is only a limited number of patients that do not qualify for implant therapy and may thus not benefit from improved quality of life associated with fixed implant-retained prostheses.

Implantes de zircônia reforçada com ítria (Y-TZP): avaliação histomorfométrica / Y-TZP dental implants: histomorfometry analysis

O objetivo do trabalho foi avaliar in vivo a osseointegração de implantes produzidos em zircônia reforçada com ítria (Y-TZP) e compará-los com o implante de titânio usinado e com o de superfície jateada com brushita. Para tanto, nas tíbias de 20 coelhos machos (n=10) e fêmeas (n=10) foram implantadas em uma das tíbias o implante Y-TZP (GE-1, n=10 implantes) e na outra tíbia o titânio usinado (GC, n=5 implantes) ou jateado com brushita (GE-2, n=5 implantes). Os animais receberam marcadores ósseos fluorescentes, tetraciclina (14 e 21 dias), alizarina (28 e 35 dias) e calceína (42 e 49 dias) após a cirurgia de implantação. Ao final de 56 dias, a região dos implantes foi coletada e processada histologicamente para obtenção de cortes teciduais não desmineralizados. Nas imagens obtidas no microscópio confocal foi avaliado o percentual de área para cada marcador. Nos cortes corados pelo azul de toluidina foi avaliado morfologicamente a qualidade do tecido ósseo formado e a existência de interposição de tecido conjuntivo entre osso e implante, e morfometricamente determinado o percentual de contato osso-implante (BIC) e o percentual de tecido ósseo próximo à superfície do implante (BA). Os resultados mostraram que, não houve diferenças estatisticamente significantes entre machos e fêmeas quanto aos parâmetros avaliados. Com relação aos grupos, GE-1 e GC apresentaram cortical óssea remanescente íntegra e formação de um tecido ósseo maduro/lamelar na superfície dos implantes. No GE-2 ocorreu intensa reabsorção da cortical óssea pre-existente próxima ao implante e extensa formação óssea mais imatura em relação aos observados no GE-1 e GC. Essa intensa reabsorção e extensa formação óssea fez com que o percentual de área dos marcadores fluorescentes fosse em média 0,73 vezes maior no GE-2 em relação aos grupos GE-1 e GC. Com relação ao BIC não houve diferença entre os grupos, sendo em média de 47,8%, porém, o BA no grupo GC (66,2%) foi 0,33 vezes...

The aim of this work was evaluate in vivo the osseointegration of implants produced with yttria stabilized zirconia (Y-TZP) and compare it with machined titanium implant and sandblasted surface with brushita titanium. Therefore, on the tibia of 20 rabbits males (n=10) and female (n=10) were implanted in one of the tibias the implant Y-TZP (GE-1, n=10 implants) and on the other tibia the machined titanium (GC, n=5 implants) or sandblasted surface with brushita titanium (GE-2, n=5 implants). The animals received fluorescent bone markers, tetracycline (14th and 21th days), alizarin (28th and 35th days) and calcein (42th and 49th days). At the end of 56 days, the implants regions were collected and histomorphometrically processed to obtain tissue sections not demineralized. On images obtained from confocal microscopy was evaluated the percentage of area for each bone markers. On slides stained with toluidine blue was measured morphologically the quality of formed bone tissue and the existence of interposition of connective tissue between bone and implant, and was morphometrically determined the percentage of bone-implant contact (BIC) and the percentage of bone tissue next to the implant surface (BA). The results showed that there were no statistically significant differences between male and female regarding to evaluated parameters. Concerning to the groups, GE-1 and GC exhibited wholesome remaining cortical bone and formation of mature/lamellar bone tissue on implants surface. In GE-2 ocurred intense reabsorption of preexisting cortical bone next to the implant and extensive bone formation more immature than GE-1 and GC. This intense reabsorption and extensive bone formation made the GE-2 area percentage for fluorescent markers 0.73 times higher on average when compared to GE-1 and GC. About the BIC, there were no differences between the groups, with an average of 47.8%, however, the BA on GC group (66.2%) was 0.33 higher compared to GE-1...

The establishment of a two-dimensional infinite element analysis model for endodontic endosseous implants / 实用口腔医学杂志

砄bjective: To establish two dimensional infinite model for endodontic endosseous implants in order to set up infinite element method and study the stress distribution of the apical foramen area of endodontic endosseous implant. Methods: Based on the analysis of two dimensional endodontic endosseous implants model with finite element method, left and right areas beside the apical foramen were selected as infinite domains including implant dentin and ligament sections. D N interactive method was used to connect the finite and infinite domains. Results: After ten times interaction between finite and infinite domains with D N interactive method, the outcome approached to a stable numerical value close to the displacement of both domains. Conclusion: The infinite model of two dimensional endodontic endosseous implants established by D N interactive method is efficient and accurate.

A histological study on experimental implantation of ?-tricalcium phosphate in rabbit mandible / 实用口腔医学杂志

砄bjective:To study the biocompatability and absorption of ? tricalcium phosphate doped A10 (? TCP A) and ? tricalcium phosphate doped SrO (? TCPs) in the implantation into mandible.Methods:Pieces of ? TCP A,? TCPs or ? TCP (? tricalcium phosphate) in the size of 10 mm?3 mm? 2.5 mm were implanted into the defects of mandible in 48 rabbits.The specimens were obtained 2,4,12 and 24 weeks after operation respectively,measured for size and observed morphologically, the content of Ca,P and S in the specimens was measured with EDAX.Results:The absorption (%) of ? TCP A,? TCPs and ? TCP in 24 weeks was 22,28 and 40 respectively.Bone formation was found in the interface between the mandible and materials in 4 weeks and the amount of new bone in the materials increased in 12～24 weeks.No inflammation was found.The amount of Ca,P and S in the materials was close to that in the mandible of rabbit in 24 weeks.Conclusion:? TCP A and ? TCPs are biocompatable for implantation into bone deffect.

Improvement of osseointegration of titanium dental implant by modified sandblasting surface treatment / 实用口腔医学杂志

Objective:To study the effects of the modified sandblasting surface treatment on the bone implant interfacial shear strength of titanium dental implant.Methods:Titanium implants with smooth surface or modified sandblasted surface were inserted into femoral medialis condyli of dogs at random.The samples of implant with surrounding bone tissue were prepared in blockes and the shear strength of the interface was measured with Instron electronic pull out tester 2,4 and 12 weeks after operation. The modified sandblasted surface of the implant was observed with SEM and X ray spectroscopy 12 weeks after operation.Results:2 and 12 weeks after implantation the shear strength(MPa) between bone tissue and implants with modified sandblasted surface was 4.28?0.88 and 7.54?0.34 respectively,that between bone tissue and implants with smooth surface 0.09?0.08 and 1.43?0.46 respectively.SEM and X ray spectroscopy observation revealed that the most parts of the sandblasted surface of the implants were covered by bone tissue and bone matrix deposited into the pores created by the acid etching.Conclusion:The rough surface of titanium dental implant created by the modified sandblasting surface treatment can enhance the shear strength between bone tissue and implant.

Augment of alveolar ridge by distraction osteogenesis in dogs / 实用口腔医学杂志

0.05) respectively.Conclusion:Distraction osteogenesis can be used for alveolar ridge augment and for the application of dental implant.

Stress analysis of one-piece spiral implant / 实用口腔医学杂志

砄bjecat:To study the correlatiom between stress and structure of one piece spiral implant.Methods: The morphology of alveolar bone was selected by CT around the first molar of mandible and around the incisor of maxilla of a healthy man in the position of normal occlusion. Cortical bone with the thickness of 1～2 mm was used to make the alveolar bone model. The one piece spiral implants with root, in the shape of cylinder, length of 10,12, 13 and 14 mm, corona height of 4 and 9 mm,diameter of 3.6,3.7, 3.8,3.9 and 4.0 mm were prepared respectively. The implants were put into the alveolar bone models and a load of 200 N was applied vertically, or 45 ℃ obliquely or 45℃ non center obliquely. The stress on the implants was measured and studied with 3D FEM. Results:The stress on the implants was inversely correlated to the length and diameter in the place of front teeth and molars except non centeraly obliquely loading to molar. The greatest stress was found around the neck of the implants. The distribution and intensity of the stress were related to the way of loading and the elastic modulus of bone. Conclusion:The length and diameter of one piece implant are the factors correlated to the stress on the implant and surrounding bone.

Comparative study of mini-implant for orthodontic anchorage and traditional anchorge in cuspid retration in adult patients with bimaxillary protrusion / 实用口腔医学杂志

0.05) . Conclusion: Mini-implant can replace traditional anchorge composed of extraoral arch and Nance arch in the moving of cuspid distally.