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Aims and Objectives: To investigate the experience of implant complications and opinions on complications among dentists in private practices in Ontario. Methods: In 2010, a web-based anonymous survey was distributed to 2034 Ontario dentists with valid e-mail addresses. Results: 527 dentists replied to the survey, of which 469 utilized implants. Most complications were preventable. The most important cause of complications was “poor planning”. The most severe complication was “permanent paraesthesia”. Fewer than 5% of patients experienced a complication in 2009. There was little agreement among general dentists, oral surgeons, periodontists, and prosthodontists on the causes of complications, some agreement on preventive strategies to avoid complications, and significant agreement on severity of complications and their preventability. Conclusions: A significant proportion of dentists in Ontario had encountered an implant treatment complication in 2009. Since most complications are preventable, efforts at decreasing their prevalence and severity should be pursued.

Aims and Objectives: To investigate the experience of implant complications and opinions on complications among dentists in private practices in Ontario. Methods: In 2010, a web-based anonymous survey was distributed to 2034 Ontario dentists with valid e-mail addresses. Results: 527 dentists replied to the survey, of which 469 utilized implants. Most complications were preventable. The most important cause of complications was “poor planning”. The most severe complication was “permanent paraesthesia”. Fewer than 5% of patients experienced a complication in 2009. There was little agreement among general dentists, oral surgeons, periodontists, and prosthodontists on the causes of complications, some agreement on preventive strategies to avoid complications, and significant agreement on severity of complications and their preventability. Conclusions: A significant proportion of dentists in Ontario had encountered an implant treatment complication in 2009. Since most complications are preventable, efforts at decreasing their prevalence and severity should be pursued.

Resumo: O Diabetes mellitus (DM) é uma alteração metabólica que pode comprometer a estabilidade do implante dentário devido a influência no tecido ósseo. O objetivo do estudo foi avaliar o efeito do Diabetes Mellitus e da insulinoterapia na osseointegração estabelecida ao redor de implantes instalados em tíbia de ratos. Foram utilizados 80 ratos Wistar, os quais foram divididos em 4 grupos: controle de 2 meses (C2m), controle de 4 meses (C4m), diabético (D) e insulínico (I). Os implantes de superfície lisa (2,2mmx4mm) foram instalados na tíbia do rato. Após um período de 2 meses para osseointegração, o grupo C2m foi sacrificado. A indução do DM foi realizada com dose única de estreptozotocina (40mg/Kg) pela veia peniana. Os ratos do grupo I receberam insulina subcutânea (8,5 U/dia) e os demais receberam solução salina (0,9%) pela mesma via. Os níveis da glicemia plasmática foram avaliados periodicamente pelo método enzimático da glicose-oxidase. Dois meses após a indução do DM, os grupos C4m, D e I foram sacrificados. A relação do tecido ósseo com o implante foi avaliada pelas análises: radiográfica (subtração radiográfica digital); bioquímica; histométrica e torque de remoção do implante. Os dados das análises radiográfica, bioquímica e histométrica foram comparados nos grupos pelo teste ANOVA, p>0,05. Os dados da análise do torque de remoção foram comparados nos grupos pelo teste Kruskal Wallis e Friedman, p>0,05. Os resultados mostraram que o grupo D apresentou níveis de glicemia plasmática acima de 300mg/dL e significativamente mais alto do que os grupos C4m e I após a indução do DM e esta condição sistêmica foi mantida até o final do experimento. / Abstract: The Diabetes mellitus (DM) is a metabolic disease that can impair the dental implant establishment by bone tissue influence. The aim of this study was evaluate the effect of Diabetes Mellitus (DM) and insulin therapy on osseointegration around dental implants. Eighty implants were placed in 80 tibiae of adult rats. After a healing period of two months, the animals were divided into four groups of 20 animals each and subdivided into 10 rats for removal torque analysis and 10 rats for histometric analysis. Group C2m was sacrificed at this time. DM was induced using 40mg/kg Streptozotocin in a diabetic group (group D) and an insulinic group (group I). During two months, group I received subcutaneous doses of 8.5 UI insulin twice a day. Groups C4m (control of 4months) and D received only saline. After two months, the animals of groups D, I and C4m were sacrificed. The glycemic control of the animals was monitored during the experiment. The relation of bone with implant was evaluated by 18 radiographic (digital subtraction radiography), bioquimic, histometric and removal torque analysis. Data obtained with radiographic, bioquimic and histometric analysis were analyzed and compared by ANOVA test, p>0,05. Data obtained with removal torque analysis were analyzed and compared by Kruskal Wallis and Friedman tests, p>0,05. The glycemic controls were within normal range for groups A, C and I and higher for group D and maintained during experiment. Greater significant values of ALP serum and Ca urinary were determined in group D after DM induction. There was a significant difference in gray shade values in the subtraction image between groups D (123±9) and I (136±5) (p<0.05) on bone formation around the implant while there were no significant differences between control groups A (127±13) and C (133±10) and insulinic group. / Orientador: Gulnara Scaf / Coorientador: Elcio Marcantonio Junior / Banca: Julio César Joly / Banca: Maria Lúcia Rubo Rezende / Banca: Guilherme Monteiro Tosoni / Banca: Marisa Aparecida Cabrini Gabrielli / Doutor

This retrospective clinical study aimed: (1) to establish and validate a reproducible geometrical measurement strategy in quantifying peri-implant alveolar bone changes based on CBCT images taken before and one year after implantation; (2) to quantify and compare the bone changes of Type 1 and Type 4 implant placement in the patient cohort that requested implant placement at premolar and molar sites; (3) to analyse the bone changes in relation to the two implant protocols in aspects of buccal and lingual, maxilla and mandible, within the cohort and combined cohorts. 3D imaging analysis in this study had used a software package - OnDemand3D. The evaluation of the measurement strategy was based on a simulation model which was made of human dry skull with and without a standard implant (Straumann Standard Plus, Ø3.3 mm diameter, L12 mm) to simulate before and after the implant placement. The recruited cases were 69 (44 Type 1 cases and 25 Type 4 cases); all data sets were provided by Shanghai 9th people's hospital, China. Each case had two CBCT data sets at before and one year after implant placement. With 69 cases, bone grafting was applied to all Type 1 cases, and the flap surgery was applied to Type 1 cases when buccal bone recession greater than 3 mm. The measurements were made in bone height (HL) and bone thickness (L0O0, L1O1, L2O2, L3O) at lingual side, while the same at buccal side (HB, B0O0, B1O1, B2O2, B3O3). The four sections of bone thickness were at 0, 1 mm, 4 mm and 7 mm from the top of the implant. Additionally, six special cases were reported, as they provided extra information. They were two spilt-mouth control cases, three 2-year follow-up cases and one 3-year follow-up case. The evaluation of the measurement strategy showed the error of the measurement strategy was -0.06 mm and the measurement uncertainty was ±0.05 mm. The main measurement outcomes from the clinical cases were as follows: (1) at buccal side, the mean value of bone changes in height was a positive value of +0.18±1.64 mm for Type 1, which was significantly more than +0.01±0.86 mm for Type 4 (p < 0.05). However the standard deviation over the 44 and 25 patient cohorts were as large as 1.64 mm and 0.86 mm; (2) at buccal side, the bone changes in thickness showed significantly more loss at B0O0 (p < 0.01) and B1O1 (p < 0.05) sections in Type 1 (-0.38±1.49 mm and -0.25±1.15 mm) compared with Type 4 (-0.19±0.34 mm and -0.16±0.76 mm); (3) in Type 1 cases, the bone thickness at buccal side showed significantly more absorption at L1O1B1 (p < 0.05), L2O2B2 (p < 0.01), L3O3B3 (p < 0.01) section (-0.25±1.15 mm, -0.19±0.99 mm, -0.12±0.57 mm) compared to lingual side (-0.13±0.85 mm, -0.16±0.28 mm, -0.05±0.28 mm); and the bone height (+0.18±1.64 mm) increased significantly more at buccal side than lingual side (-0.25±0.79 mm) with bone augmentation procedure (p < 0.01). However, within Type 4 cases, no significant difference in bone changes between buccal and lingual sides could be found. In conclusion, the measurement strategy established in this study was reproducible and provided valid quantifiable data of bone changes in relation to implant placement based on 3D CBCT images. The data analysis from these two patient cohorts suggested that Type 1 implant placement protocol could re-build the bone height at buccal side better than Type 4.

The master’s thesis deals with issues belonging to the field of dental biomechanics, specifically the mechanical interaction of dental implants with the bone tissue of the mandible. The thesis focuses on the stress-strain analysis of the mandible with the implant inserted in different positions, with a different angle relative to the occlusal plane. The solution is performed by computational modeling using the finite element method. The geometry model of mandible was created based on CT images. The aim of the master’s thesis was also to compare the influence of the choice of the material model of cancellous bone tissue on the resulting stress-strain states of the mandible with the dental implant. Three material models of cancellous bone tissue were created - two homogeneous material model and a heterogeneous material model, which was based on CT image data. The work also investigates the effect of rotation (+5° or -5°) of implants in basic positions on the resulting stress-strain states. The stress-strain analysis showed that position and rotation has a greater effect on the stress and strain of bone tissue and implant than the chosen material model of cancellous bone tissue.

<p><span style="font-size: 8pt / " text-align:="" font-family:="" color:="">The edentulous jaw is a common feature in elderly patients that had lost their teeth during life due to local reasons such as poor oral hygiene and dental caries as well as periodontal disease. Hence these patients are the victims of biological phenomenona that lead to difficulties in different aspects of patient comfort with dentures. Clinicians are always concerned to minimize these difficulties and increase patient comfort through manufacturing a proper prosthesis to substitute for the loss of the natural teeth as well as the surrounding structures for optimum satisfaction and improved quality of life of the patient. The aim of this study was to evaluate patient satisfaction regarding function and aesthetics with conventional mandibular dentures and implant retained mandibular overdentures in denture wearers.</span></p>

Osseointegration is defined as the direct physical and practical relation between the living tissue and implant surface. Although, success rate of dental implants is high, implant failure occurs. Overloading implants from occlusal forces are known as one of the main reasons. In order to have successful implant, a dynamic balance must be provided between mechanical and biological elements (Isidor, Flemming 1996). Şimşek et al. reported bone quality, oral sanitation, host medical condition and biomechanical parameters as the main reasons for implants failure. Also, implant fixture micromotion and inappropriate stress in the bone implant interface is known as the potential reasons for early bone loss and implant failure (Şimşek, Barış 2006). Even so, implant position in jawbone, bone density; biomaterial properties of implant surface, treatment technique, loading history and patient clinical status are the influential factors in implant success (Brunski, J.B. 1999). Although there are many studies on stress distribution of implants in bone-implant interface, majority are limited to current implants in the market. However, current designs have been developed by marketing purposes rather than scientific considerations. Therefore, there is need to introduce and analyse new designs in order to optimize implant structure. Recent investigations have shown reliability of FEA method in simulating human jawbone situation. This research aims to develop a new dental implant with better life expectancies and introduce an optimized implant based on FEA stress analyses and experimental tests. Therefore, based on literature recommendations a series of new design factors are defined and analysed. In this study, a primary design is created in AutoCAD and yields to 3 different implants developed in SolidWorks. Branemark MK IV was selected as the bench model to play role of control group. Then, CT-scan images of human jawbone are imported to MIMICS to create a host bone model. Implant and jawbone models are assembled in 3-Matic and exported to Abaqus for final analyses. A series of loadings are defined to examine implant performance in different conditions. Branemark and C-3 implants are manufactured from Titanium for experimental analyses. Mechanical tests on sawbone foam blocks and cadavers are targeted to portray realistic performance. This research demonstrates C-3 model as the optimized dental implant, which presents a new design profile and better performance in low bone densities. The FEA and experimental results validate the benefit of the new design compare to the conventional ones. Furthermore, results can provide a basis for future designers to develop further optimizations.

O presente estudo teve como objetivo avaliar a resposta biológica ao redor de implantes de titânio grau IV (titânio comercialmente puro) e grau V (Ti6Al4V), com diferentes tipos de tratamentos de superfície através da análise do contato ossoimplante (bone implant contact - BIC) e da área de neoformação óssea com e sem fluorocromo (bone area BA e BAfluo) das 3 primeiras roscas em contato ósseo de cada implante. Para isso, utilizou-se um total de 90 implantes Cone Morse de titânio grau IV (Drive 45 implantes) e titânio grau V (Facility 45 implantes), com dimensões de 3.5x8mm e 2.9x7mm, respectivamente. Estes dois tipos de implantes foram avaliados em três tratamentos de superfícies diferentes: a) superfície com jateamento com partículas abrasivas seguido de tratamento ácido - NeoPoros (NP) - em embalagem seca (Grupo Controle); b) superfície jateada seguido de tratamento ácido e energia de superfície, armazenado em líquido (ESm); c) superfície jateada seguido de tratamento ácido com energia de superfície e embalado a seco (ESs); totalizando 6 grupos, distribuídos em 15 coelhos New Zealand, em cada um foram instalados 6 implantes, sendo 3 em cada tíbia. Após 15 dias de osseointegração, os coelhos passaram por eutanásia e as tíbias seccionadas, fixadas e incluídas para a avaliação histológica e histomorfométrica. Mensurações no analisador de imagens ImageJ foram realizadas e a análise dos dados estatísticos, de todos os grupos foram avaliados através da análise de variância a dois critérios e do teste de Tukey para comparações múltiplas grupo a grupo, adotando o nível de significância de 5% (p<0,05). Os resultados mostraram que não houve diferença estatisticamente significante entre os dois tipos de titânio, porém houve diferença estatisticamente significante entre os tipos de superfície em relação ao BIC, BA e BAfluo; também, não houve interação entre titânio e superfície. Na análise do contato osso-implante (BIC) a superfície ESm teve melhor desempenho em relação ao NP, que por sua vez foi semelhante ao ESs. Quanto à área óssea (BA), a superfície NP teve menor desempenho em relação à ESs, este obteve semelhante desempenho a ESm. Quanto a área ósseo neoformada com presença de fluorocromo (BAfluo), NP teve menor desempenho em relação ao ESs, o qual obteve semelhante comportamento a ESm. Com isso, concluiu-se que implantes de titânio de gau IV e grau V obtiveram respostas biológicas equivalentes, enquanto que a energia de superfície com a molhabilidade podem ser consideradas como vantagem, uma vez que otimizam o processo de osseointegração. / This study aimed to evaluate the biological response around grade IV (commercially pure titanium) and grade V (Ti6Al4V) titanium implants with different types of surface treatments by analyzing bone-implant contact (BIC) and the bone formation area with and without fluorochrome (BA and BAfluo) of the 3 first threads on bone contact of each implant. To this end, this study used 90 Morse Taper grade IV (Drive - 45 implants) and grade V (Facility - 45 implants) titanium implants, measuring 3.5x8mm and 2.9x7mm, respectively. Both types of implants were evaluated in three different surface treatments: a) blasted/acid-etched implant surface - NeoPoros (NP) - dry pack (control group); b) blasted/acid-etched implant surface and surface energy, stored in liquid (ESm); c) blasted/acid-etched implant surface with surface energy and dry packed (ESs); totalizing 6 groups, distributed in 15 New Zealand rabbits. Six implants were placed in each rabbit, 3 in each tibia. After 15 days of osseointegration, the rabbits were euthanized and the tibias sectioned, fixed and embedded for histologic and histomorphometric evaluation. Measurements were carried out using the image analysis program ImageJ and the assessment of statistical data concerning all groups was done through the two-way analysis of variance and the Tukey test for multiple comparisons group to group, adopting the significance level of 5% ( p <0.05). The results showed no statistically significant difference between the types of titanium used. However, there were statistically significant differences between the types of surface in relation to the BIC, BA and BAfluo. In addition, there was no interaction between titanium and the surface. Concerning the analysis of bone-implant contact (BIC), the ESm surface had better performance compared to the NP, which, in turn, was similar to the ESs. As for bone area (BA), the NP surface had lower performance in relation to the ESs surface, as the latter had a similar performance to the ESm surface. Concerning the newly formed bone area with presence of fluorochrome (BAfluo), the NP had lower performance if compared to the ESs, which behaved similarly to that of the ESm surface. Thus, this study concluded that grade IV and grade V titanium implants showed equivalent biological responses, while the surface energy, together with its wettability, can be considered an advantage, enhancing the osseointegration process.

O tecido adiposo pode regular o metabolismo ósseo e estar envolvido na fisiopatologia da osteoporose, sendo este fator determinante no sucesso de tratamentos reabilitadores com implantes dentários osseointegrados. O presente estudo de coorte prospectivo teve como objetivo verificar o padrão ósseo alveolar por meio de índices radiomorfométricos da radiografia panorâmica e medidas lineares realizadas em radiografias periapicais, em pacientes eutróficas e obesas mórbidas antes e após a cirurgia bariátrica. A amostra foi constituída por 31 mulheres com idade de 20 a 35 anos, sendo divididas em 2 grupos: Grupo Experimental (GE-Obesas de Grau III, IMC >40 Kg/m2) e Grupo Controle (GC- Eutróficas, IMC 18,5 a 24,99 Kg/m2). Foram avaliadas 20 eutróficas e 11 obesas mórbidas no pré e pós-cirurgia bariátrica (6 meses). Índices radiomorfométricos e de placa dentária foram avaliados nos tempos T0 (baseline) e T1 (6 meses). Na análise radiográfica foram avaliados o padrão trabecular através da escada visual de Lindh e a perda óssea por meio do cálculo da distância da junção cemento-esmalte à crista óssea, em radiografias periapicais. Já as radiografias panorâmicas para mensurar Índice da Cortical Mandibular (ICM), Índice Mentoniano (IM) e Índice Panorâmico Mandibular (IPM), além do índice de Placa de Turesky. Houve perda óssea significativa em T1 nas pacientes submetidas à cirurgia bariátrica, quando comparada com as eutróficas (p<0,05). O padrão trabecular tornou-se mais esparso após a cirurgia apresentando uma diferença visual. No índice de placa foi observada uma ligeira melhora após a cirurgia e os eutroficos mantiveram valores similares ao longo do tempo. Pode-se concluir que pacientes obesas apresentam maior perda óssea, a qual piora após a cirurgia bariátrica, quando comparada com o de pacientes eutróficas. O mesmo acontecendo com o trabeculado ósseo que se torna mais esparso após a cirurgia bariátrica. / Adipose tissue can regulate bone metabolism and be involved in the pathophysiology of osteoporosis, being this determinant factor in the success of rehabilitative treatments with osseointegrated dental implants. The present prospective cohort study aimed to verify the alveolar bone pattern through radiomorphometric indices of panoramic radiography and linear measurements performed in periapical radiographs in eutrophic and morbidly obese patients before and after bariatric surgery. The sample consisted of 31 women aged 20-35 years old, divided into 2 groups: Experimental Group (GE-Obesas de Grade III, BMI> 40 Kg / m2) and Control Group (GC-Eutrophic, BMI 18.5 To 24.99 kg / m2). 20 eutrophic and 11 obese morbidities were evaluated in the pre and postoperative bariatric surgery (6 months). Radiomorphometric and plaque indices were evaluated at T0 (baseline) and T1 (6 months) times. In the radiographic analysis the trabecular pattern through the Lindh visual ladder and the bone loss were evaluated by calculating the distance from the cemento-enamel junction to the bone crest in periapical radiographs. Panoramic radiographs were used to measure the Mandibular Cortical Index (ICM), Mentonian Index (IM) and Panoramic Mandibular Index (MPI), in addition to the Turesky Plate index. There was a significant loss of bone in T1 in patients submitted to bariatric surgery, when compared to eutrophic patients (p <0.05). The trabecular pattern became more sparse after surgery with a visual difference. The plate index showed a slight improvement after surgery and the eutrophic maintained similar values over time. It can be concluded that obese patients present greater bone loss, which worsens after bariatric surgery, when compared to that of eutrophic patients. The same happens with the trabecular bone that becomes more sparse after bariatric surgery.