Os fatores que possam promover e incrementar a osseointegração, ou prejudicar o processo biológico, aumentando o índice de falhas, têm sido cada vez mais investigados com o objetivo de ampliar indicações e as taxas de sobrevivência dos implantes dentais assim como controlar fatores adversos. O objetivo desta tese foi identificar, analisar e sintetizar as evidências científicas quanto a influência das estatinas, do envelhecimento e da experiência do cirurgião no processo osseointegração e na sobrevivência de implantes dentais. Este volume apresenta um compilado de três revisões sistemáticas orientadas pelas recomendações PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). O processo de revisão foi realizado por meio de uma busca sistemática em cinco bases de dados eletrônicas (PubMed, Scopus, Web of Science, Embase e Cochrane Library), além de busca manual nas referências bibliográficas dos estudos incluídos. A meta-análise, quando cabível, foi realizada com o auxílio do software Review Manager (RevMan, Versão 5.3). O grau de heterogeneidade entre os estudos foi verificado por meio do teste Q de Cochran e I2. O viés das publicações foi avaliado com o auxílio das escalas Newcasttle-Ottawa e Cochrane Collaboration\'s Tool. A síntese dos dados permitiu a publicação de três artigos científicos dispostos nesta tese. / Factors that may promote and enhance osseointegration, or impair the biological process, have been increasingly investigated in order to expand the indications and survival rates of dental implants and control the adverse factors. The aim of this thesis is to identify and summarize the scientific evidence of statins, ageing and surgeon related factors that can influence osseointegration and survival of dental implants. This volume presents a compilation of three systematic reviews structured by PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The review process was carried out through a systematic search in five electronic databases (PubMed, Scopus, Web of Science, Embase and Cochrane Library) and bibliographical references of the included studies. Meta-analyses, when appropriate, were performed using the software Review Manager (RevMan version 5.3). The degree of heterogeneity in the studies was verified by Q Cochran test and I2. The bias of the publications was assessed with the assistance of Newcastle-Ottawa Scale and Cochrane Collaboration Tool\'s. The synthesis of the data was included in three papers prepared for this thesis.

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.

In the twenty-first century, new cutting-edge osseointegration technology is improving quality of life. Osseointegration is a new technique to suspend an implant prosthetic device for individuals with a limb-loss. The science of osseointegration is not clearly understood although there appears to be a special relationship between pure titanium that promotes activation of our bone building cells and bone remodeling. Direct bone-anchored osseointegration to integrate a foreign device into the body without the body rejecting the prosthesis is the new technology lacking knowledge and research clinical cases for human translation. The objective of the case study was to review the science of bone-anchored osseointegration as a limb-salvaging technique and potential translation to humans using a canine model in a well-defined control study. Aims were to enhance knowledge technology, improve mobility, decrease pain to improve quality of life and influence health care practices. By the year 2050, the projected number of American amputees is expected to reach 3.6 million. Many people depend on artificial limbs to perform their activities of daily living. Often these limbs start developing complications associated with stump-socket designs such as separation from the human tissue, poor fit with repeated fittings, recurrent skin infections, ulcers and pressure sores due to non-uniform pressure distribution over the socket contact area and pain which decreases their mobility. Since 2001, close to 28,500 American troops have been wounded in combat in Iraq and Afghanistan. Greater than 24,600 of them have survived their injury, the highest survival rate of any war in the history of the United States. Sadly, 700 of these services members have lost at least one limb from amputations. Lower limb amputations are still performed above the knee as not enough bone can be preserved below the knee for prosthesis. Osseointegration with limb-salvaging techniques could enhance mobility and quality of life for those individuals who sacrifice their limbs defending our freedoms.

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.

Thesis (M.S.)--University of Tennessee Health Science Center, 2007. / Title from title page screen (viewed October 10, 2007). Research advisor: Joo L. Ong, Ph.D. Document formatted into pages (vi, 22 p. : ill.) Vita. Abstract. Includes bibliographical references (p. 23-32).

Thesis (Ph.D.)--Tufts University, 2004. / Adviser: David L. Kaplan. Submitted to the Dept. of Biotechnology Engineering. Includes bibliographical references (leaves 162-222). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M.S. )--University of Tennessee Health Science Center, 2007. / Title from title page screen (June 30, 2008). Research advisor: Joo L. Ong, Ph.D. Document formatted into pages (vi, 47 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 41-46).

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 205-223).

Thesis (Ph. D.)--University of Alabama at Birmingham, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Alabama at Birmingham, 1999. / Includes bibliographical references.