Comparison of Manual (2D) and Digital (3D) Methods in the Assessment of Simulated Facial Edema.

BACKGROUND: An edema assessment following dental surgeries is essential to improving the dental surgeon's technique and, consequentially, patient comfort. PURPOSE: Two-dimensional (2D) methods are limited in analyzing 3-dimensional (3D) surfaces. Currently, 3D methods are used to investigate postoperative swelling. However, there are no studies that directly compare 2D and 3D methods. The goal of this study is to directly compare 2D and 3D methods used in the assessment of postoperative edema. STUDY DESIGN AND SAMPLE: The investigators implemented a prospective, cross-sectional study with each subject serving as its own control. The sample was composed of dental student volunteers without facial deformities. PREDICTOR VARIABLE: The predictor variable is the method used to measure edema. After simulating edema, manual (2D) and digital (3D) techniques were used to measure edema. The manual method used direct facial perimeter measurements. The two digital methods were photogrammetry using a smartphone (iPhone 11, Apple Inc, Cupertino, California), and facial scanning with a smartphone application (Bellus3D FaceApp, Bellus3D Inc, Campbell, California) [3D measurements] MAIN OUTCOME VARIABLE: The coefficient of variation (CV) (CV = standard deviation /mean) was used to assess homogeneity of edema measurements. ANALYSIS: The Shapiro-Wilk and equal variance tests were applied to assess data homogeneity. Next, one-way analysis of variance was performed, followed by a correlation analysis. Finally, the data were submitted to Tukey's test. The statistical significance threshold was set at 5% (P < .05). RESULTS: The sample was composed of 20 subjects aged 18-38 years. The CV showed higher values using the manual (2D) method (47%; 4.88% ± 2.99), compared with the photogrammetry method (18%; 8.55 mm ± 1.52) and the smartphone application (21%; 8.97 mm ± 1.93). A statistically significant difference was observed between the manual method values and those of the other two groups (P < .001). There was no difference between the facial scanning and photogrammetry groups (3D methods) (P = .778) CONCLUSION AND RELEVANCE: Both digital measuring methods (3D) demonstrated greater homogeneity than the manual method in analyzing facial distortions caused by the same swelling simulation. Therefore, it can be affirmed that digital methods may be more reliable that manual methods for assessing facial edema.

A systematic review and meta-analysis of the clinical performance of implant-supported overdentures retained by CAD-CAM bars

Abstract Currently, there is no consensus on the indications and clinical performance of implant-supported overdentures (IODs) involving computer-aided design and manufacturing (CAD-CAM) bars. Objective: To evaluate the performance of IODs involving CAD-CAM bars. Methodology: A comprehensive search of studies published until May 2023 was conducted in many databases, including PubMed/MEDLINE, Web of Science, Cochrane Library, and SciELO, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The population, intervention, comparison, outcome (PICO) question was: "How do IODs retained by bars fabricated by CAD-CAM technology perform in daily clinical practice?" The meta-analysis included clinical studies based on effect size and a two-tailed null test with a 95% confidence interval (CI). Results: Ten studies were included in the meta-analysis. Among them, nine reported a 100% implant survival rate for all CAD-CAM milled bars. Complications were reported in two studies with CAD/CAM-milled titanium bars, and one study reported more fractures in soldered gold bars used in maxillary rehabilitation. However, no fractures were observed in IODs retained by PEEK and zirconia bars. According to six studies, biological complications, including peri-implantitis, were minimal in the BioHPP and PEEK bar groups, while no cases were reported in the titanium or zirconia bar groups. CAD-CAM-milled zirconia bars had higher plaque and bleeding indices compared with titanium bars, as evidenced by findings from five studies. All four studies that evaluated Oral Health Impact Profile (OHIP) scores showed a positive effect of IODs retained by CAD-CAM milled titanium bars on quality of life. Patient satisfaction and acceptance by prosthodontists were significantly high, according to the results of five studies. Conclusion: Overdentures retained with CAD-CAM milled titanium bars show great potential for use in daily clinical practice. Moreover, patient and practitioner satisfaction was very high when this method was used.

Titanium Allergy Caused by Dental Implants: A Systematic Literature Review and Case Report.

(1) Background: Hypersensitivity reactions to metals may arise in predisposed patients chronically exposed to metallic materials, including dental implants made of titanium alloys. The purpose of this article was to systematically review titanium allergy manifestations in patients treated with dental implants and report a clinical case; (2) Methods: A systematic electronic search was performed for articles published in the English language until July 2021. The following eligibility criteria were adopted: (1) Population: individuals undergoing titanium and/or titanium alloy implant-supported rehabilitations; (2) Exposure: peri-implant soft tissue reactions attributable to implant insertion; (3) Outcome: evidence of titanium allergy, diagnostic methods, and forms of resolution; (3) Results: The included studies, in summary, presented evidence that titanium should not be considered an inert material, being able to trigger allergic reactions, and may be responsible for implant failure. A 55-year-old male patient received 3 implants in the posterior region of the left mandible and presented an epulis-like lesion developed from the peri-implant mucosa. The immunohistochemical analysis of the biopsy specimen confirmed the initial diagnosis of allergic reaction to titanium; (4) Conclusions: Although the evidence is weak, and titanium allergy has a low incidence, hypersensitivity reactions should not be underestimated. A rapid and conclusive diagnosis is mandatory to prevent further complications.

Efficiency of different protocols for oral hygiene combined with the use of chlorhexidine in the prevention of ventilator-associated pneumonia / Eficiência de diferentes protocolos de higiene bucal associados ao uso de clorexidina na prevenção da pneumonia associada à ventilação mecânica

ABSTRACT Objective: In ICU patients on mechanical ventilation (MV), ventilator-associated pneumonia (VAP) is a common infection. However, such infection can be prevented through oral care protocols. The objective of this study was to compare the efficiency of the use of chlorhexidine and oral hygiene protocols (brushing and clinical procedures) with that of the use of chlorhexidine alone (intervention group and control group, respectively) in decreasing the prevalence of VAP in patients ≥ 18 years of age admitted to the ICU and requiring MV. Methods: In this systematic review and meta-analysis, studies were identified through searches of various national and international databases, as well as of the gray literature, and were selected in accordance with eligibility criteria. Results: We evaluated six studies, involving a collective total of 1,276 patients. We classified the risk of bias as low in three studies, high in two, and uncertain in one; among the six risk domains evaluated, a low risk of bias was predominant in five. The results for random risks were similar in terms of direction and statistical magnitude-chi-square = 6.34; risk difference: −0.06 (95% CI: −0.11 to −0.02); I2 = 21%; p = 0.007. There was a decrease in the prevalence of VAP in the intervention group (n = 1,276) included in the meta-analysis. Conclusions: Protocols that include the mechanical removal of oral biofilm in combination with the use of chlorhexidine can reduce the incidence of VAP among ICU patients requiring MV.

RESUMO Objetivo: A pneumonia associada à ventilação mecânica (PAVM) é uma infecção frequente em UTI. No entanto, essa infecção pode ser evitada através de protocolos de cuidados orais. O objetivo deste estudo foi comparar a eficiência de protocolos de higiene bucal (escovação e procedimentos clínicos) aliados ao uso de clorexidina (grupo intervenção) com a de protocolos que fazem uso somente de clorexidina (grupo controle) na diminuição da prevalência da PAVM em pacientes adultos (≥ 18 anos) internados em UTI sob VM. Métodos: Nesta revisão sistemática e meta-análise, várias bases de dados nacionais e internacionais foram utilizadas para a identificação e seleção de estudos e literatura cinza seguindo critérios de elegibilidade. Resultados: Foram incluídos seis estudos, envolvendo 1.276 pacientes. Após a classificação dos estudos, três apresentaram baixo risco de viés, dois apresentaram risco de viés alto, e o risco foi incerto em um; entre os seis domínios avaliados houve predomínio de baixo risco de viés em cinco deles. Os resultados para riscos aleatórios foram semelhantes em direção e magnitude estatística - qui-quadrado = 6,34; diferença de risco: −0,06 (IC95%: −0,11 a −0,02); I2 = 21%; p = 0,007. Houve diminuição na prevalência de PAVM no grupo intervenção (n = 1.276) incluídos na meta-análise. Conclusões: Protocolos que incluem a remoção mecânica do biofilme associada ao uso de clorexidina podem reduzir a incidência de PAVM em pacientes internados em UTI sob VM.

Coronavirus (SARS-CoV-2) and the risk of obesity for critically illness and ICU admitted: Meta-analysis of the epidemiological evidence.

OBJECTIVES: To investigate the relationship between coronavirus disease 2019 (COVID-19) and obesity in critically ill patients admitted to the intensive care unit (ICU). METHODS: We systematically searched PubMed, SCOPUS, Embase, LILACS, and Web of Science for studies published up to April 27, 2020. The outcome of interest was composite poor outcome, comprising mortality and severe COVID-19. We used a standardized data extraction form to collect information from published reports of eligible studies. Heterogeneity and publication bias were assessed using I2 statistic and funnel plots, respectively. RESULTS: Nine studies including 6577 patients were selected for evaluation. The COVID-19 patients were 59.80% male and had comorbidities such as hypertension (51.51%), diabetes (30.3%), cardiovascular disease (16.66%), lung disease (15.99%), renal disease (7.49%), cancer (5.07%), and immunosuppression (1.8%). For patients with severe complications, the overall pooled event rates were 56.2% (random; 95% CI: 35.3-75.1; p = 0.015; I2 = 71.461) for obesity, 23.6% (random; 95% CI: 17.9-30.5; p = 0.000; I2 = 87.705) for type 2 diabetes, 45.9% (random; 95% CI: 38.0-53.9; p = 0.000; I2 = 90.152) for hypertension, 20.0% (random; 95% CI: 7.9-42.0; p = 0.000; I2 = 94.577) for smoking, 21.6% (random; 95% CI: 14.1-31.4%; p = 0.000, I2 = 92.983) for lung diseases, and 20.6% (random; 95% CI: 15.2-27.5; p = 0.000, I2 = 85.735) for cardiovascular diseases. DISCUSSION: This systematic review indicated the relationship between obesity, ICU admission, severe COVID-19, and disease progression in patients with COVID-19. Obese patients with hypertension, type 2 diabetes, smoking habit, lung disease, and/or cardiovascular disease should be cared for with increased attention.

Laser surgery in management of medication-related osteonecrosis of the jaws: a meta-analysis.

PURPOSE: The aim of this study was to perform a systematic review and meta-analysis to evaluate the efficacy of laser therapy on medication-related osteonecrosis of the jaw (MRONJ) treatment. METHODS: This study followed PRISMA standards, and an electronic search was performed on the PubMed/MEDLINE, Scopus, and Cochrane databases. Eighty-nine articles were found. After reading the manuscripts, 15 articles remained for the review. Three of them were selected for meta-analysis. RESULTS: Female gender was predominant (72.5%), and mean age was 66.5 years. Follow-up varied between 3 and 80 months, and the most used bisphosphonate was zoledronic acid (71.6%). Stage II of MRONJ was the most prevalent (68.9%), and the mandible was the most affected site (64.5%). Qualitative data showed that treatment with laser surgery (Er:YAG) was most effective regarding complete healing of the lesion (90%) compared with other treatments. Meta-analysis data showed that low-level laser therapy (LLLT) was more effective than medical treatment (P = 0.006), and surgical treatment was more effective than LLLT (P = 0.008). CONCLUSION: Laser surgery was significantly superior to LLLT (p < 0.00001). Therefore, laser surgical therapy seems to be a great management strategy for MRONJ treatment from stage II. LLLT was shown to improve conservative management in earlier MRONJ stages.

Inflammatory response and macrophage polarization using different physicochemical biomaterials for oral and maxillofacial reconstruction.

Knowledge about the action of immune system in the recognition of biomaterials has been extremely helpful when it comes about understanding host response and biomaterials' fate in human body. This study aimed to investigate inflammatory response and macrophage polarization during bone healing process of rat's calvaria critical defects using different bone materials in order to evaluate their influence on bone repair and on the quality of the newly formed bone tissue. Eighty male albinus Wistar rats underwent surgical procedure for the confectioning of a 5-mm diameter bone defect in their right parietal bone, and divided in four groups (n = 20 each), according the biomaterial: AG - Control, particulate intramembranous autogenous bone graft, HA/TCP - particulate biphasic calcium phosphate with HA/TCP (60/40), DBB - particulate deproteinized bovine bone, VC - particulate bioactive vitroceramic. After 3, 7, 21, and 45 days, the specimens were removed and prepared for microcomputed tomography (microCT), light and polarized microscopy, immunohistochemical analysis, and histomorphometry. No significant differences were detected considering percentage of leukocytes among the groups and periods, as well as in relation to immunolabeling for inflammatory (M1) and reparative (M2) macrophages. However, immunolabeling for bone marker indicated a delayed osteoblast differentiation in VC group, resulting in a decrease in mineralized bone matrix parameters in this group, revealed by microCT. In addition, AG and HA/TCP presented a satisfactory bone collagenous content. Despite the distinct origins and physicochemical properties of the tested biomaterials, they presented similar immune-inflammatory responses in the present experimental model, influencing bone-related proteins and bone quality, which must be considered according to their use.

Distinct healing pattern of maxillary sinus augmentation using the vitroceramic Biosilicate®: Study in rabbits.

OBJECTIVES: To follow healing process of augmented maxillary sinus in rabbits analyzing the histological pattern of bone tissue formation, along with the osteogenic activity and vascularization using a bioactive vitroceramic in comparison to deproteinized bovine bone associated or not with autogenous bone graft. DESIGN: Forty five male adult New Zealand rabbits, 5 months of age, mean weight of 4 Kg, underwent bilateral sinus augmentation surgeries to be divided in five groups: G - (Control) particulate autogenous bone graft (AG), BO - deproteinized bovine bone, BO+G - deproteinized bovine bone + AG, BSi -vitroceramic, and BSi + G - vitroceramic +AG. After 15, 45 and 90 days, all animals were euthanized for specimen's removal to be analyzed under light microscopy, histomorphometry, and immunohistochemistry for Runx2 and VEGF labeling. RESULTS: G, BO and BO+G groups healed uneventfully, allowing the formation of mature remodeling bone at day 90, regarding the association of AG with the biomaterial. On the other hand, BSi and BSi + G groups showed an important cellular reaction and granulation/fibrous tissue formation from the first to the last period of observation. Runx-2 and VEGF immunolabeling were coherent with this result. However, histomorphometry did not reveal significant differences considering new bone formation. CONCLUSIONS: Reconstructed maxillary sinuses using Biosilicate® permitted satisfactory new bone formation in comparison to the deproteinized bovine bone and AG. However, the presence of granulation/fibrous tissue and inflammatory cells associated to the degrading biomaterial indicate that further studies should be careful performed considering the immunological aspect of this new biomaterial.

Clinical outcomes of pterygoid implants: Systematic review and meta-analysis.

The aim of this systematic literature review was to analyze clinical outcomes of pterygoid implant for the treatment of patients with atrophic posterior maxillae and to provide clinical recommendations for this dental implant technique. An extensive search of electronic databases (PubMed/Medline, Science Direct, Lilacs, Embase, and Cochrane Library) was conducted, for articles published between January 1995 and January 2018, to identify literature presenting clinical outcomes of pterygoid implants in the treatment of patients with atrophic posterior maxillae. The systematic review was performed in accordance with PRISMA/PICO statement guidelines, and the risk of bias was assessed (Australian National Health and Medical Research Council scale). The relative risk of implant failure was analyzed within a 95% confidence interval (95% CI). After screening 331 abstracts from the electronic databases, 36 full-text articles were accessed for eligibility, and a total of 6 studies were included in this systematic review (after applying the inclusion and exclusion criteria). All studies were retrospective in nature and were classified with a poor level of evidence. A total of 634 patients received 1.893 pterygoid implants, with a mean implant survival rate of 94.87%. The mean prevalence of implant failure was 0.056 with a 95% CI of 0.04-0.077. This study demonstrates that pterygoid implants can be successfully used in patients with atrophic posterior maxilla. However, the results should be interpreted with caution, given the presence of uncontrolled confounding factors in the included studies.

Surgical versus non-surgical treatment of actinic cheilitis: A systematic review and meta-analysis.

OBJECTIVE: The aim of this systematic review was to compare outcomes between surgical and non-surgical treatment of actinic cheilitis (AC). MATERIALS AND METHODS: A systematic review and meta-analysis based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses guideline were performed. A search of PubMed/MEDLINE, Web of Science, and Cochrane Library databases was conducted. Articles were selected based on the inclusion criteria: randomized clinical trials, prospective/retrospective studies, and case series with at least 10 patients, with a minimum follow-up period of 6 months. A weighted remission rate (RER) and recurrence rate (RR) with a 95% confidence interval was performed. Data analysis was performed using a comprehensive meta-analysis software. RESULTS: A total of 283 ACs in 10 studies were included. About 2.5% surgically treated cases underwent malignant transformation. The weighted remission rate was higher for surgical (92.8%) compared to non-surgical treatment (65.9%). The recurrence rate was lower for surgical (8.4%) compared to non-surgical treatment (19.2%). CONCLUSION: In this systematic review, the surgical treatment was more favorable than non-surgical for AC. Meanwhile, further studies are needed that should maximize methodological standardization and have greater rigor of the data collection process.

O impacto positivo na promoção de saúde bucal em jovens adolescentes / The Positive Impact on Oral Health Promotion in Young Adolescents

Introdução: o conhecimento da importância dos cuidados em saúde bucal é deficiente em âmbito escolar, ressalta-se que jovens capacitados, partilham o aprendizado assumindo papel importante na sociedade. Objetivos: capacitação de estudantes para difusão do conhecimento sobre cuidados em saúde bucal. Os temas de higienização dentária/prótese dentária e/ou implantossuportadadas e manejo após o traumatismo dentário foram abordados em escola pública. Métodos: Inicialmente, houve avaliação do conhecimento prévio dos alunos (n=25) por meio de questionários de saúde bucal, os questionários (GOHAI, higienização oral e de prótese dentária e manejo de traumatismo dentário) foram aplicados na sala de aula com supervisão. Em um próximo momento houve o treinamento dos discentes por palestras e material didático. Finalmente, após 2 meses do ciclo de formação os questionários foram aplicados novamente. Os dados foram tabulados e e análise estatística considerou o valor significativo para p<0,05, a fim de verificar o conhecimento adquirido durante o treinamento de todos os estudantes. Resultados: Identificou se pós-oficina que os jovens estavam mais satisfeitos com a aparência da boca (p<0,05). Nos questionários de higienização de próteses dentárias houve a conscientização do tempo para substituição das mesmas. Para o reimplante dentário, houve significativa percepção dos alunos como possibilidade de terapia real (p=0,016), após a realização das oficinas. Conclusão: com base nos dados, a proposta de promoção em saúde bucal para os adolescentes foi eficiente, e mais eventos (oficinas) com esta finalidade devem ser realizados em escolas de ensino médio.

Introduction: the knowledge of the importance of oral health care is deficient in the school environment, it is emphasized that empowered young people share learning, assuming an important role in society. Objectives: This study aimed to enable the training of students to disseminate knowledge about oral health care. The subjects of dental hygiene / dental prosthesis and / or implant supported and management after dental trauma were addressed in a public school. Methods: Initially, the students' prior knowledge (n = 25) was assessed through oral health questionnaires, the questionnaires (GOHAI, oral and dental hygiene and dental trauma management) were applied in the classroom with supervision. In a next moment there was the training of the students by lectures and didactic material. Finally, after 2 months of the training cycle, the questionnaires were applied again. Data were tabulated and statistical analysis considered the value significant for p students. Results: It was identified after the workshop that young people were more satisfied with the appearance of the mouth (p<0,05).In the dental prosthesis cleaning questionnaires, there was a time awareness for their replacement. For dental replantation, there was significant perception of students as a possibility of real therapy (p = 0.016), after the workshops. Conclusion: Based on the data, the proposal for oral health promotion for adolescents was efficient, and more events (workshops) for this purpose should be held in high schools.

Vertical and horizontal misfit analysis of 3-unit fdp fabricated with different techniques and cad/cam systems

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

Resumo O objetivo deste estudo foi avaliar a adaptação marginal vertical e horizontal de infraestruturas de prótese fixas de três elementos confeccionadas por diferentes técnicas e diferentes sistemas CAD/CAM. Um total de 40 infraestruturas foram confeccionadas e divididas em quatro grupos: fundição por cera perdida (G1); fundição por cera perdida com ponto de solda (G2); escaneamento óptico extraoral para escaneamento do modelo (3S/DWOS); escaneamento óptico intraoral (Cerec Bluecam/Sirona) (G4). Uma matriz metálica foi utilizada para simular uma prótese fixa de três elementos (com pôntico central). As infraestruturas do G1 e G2 foram fundidas em liga metálica de níquel-cromo (NiCr), enquanto que as infraestruturas de G3 e G4 foram fresadas em zircônia. Todos os grupos foram analisados quanto à adaptação marginal vertical e horizontal (sobrecontorno e subcontorno) em microscópio óptico tridimensional (Quick Scope, Mitutoyo). Os resultados apresentaram maiores valores de desadaptação marginal vertical no G1 comparados aos outros grupos (p<0,001). Em relação a desadaptação marginal horizontal, maiores valores de sobrecontorno foram observado no G3 em comparação com os demais grupos (p<0,001). Não foi observado valores de subcontorno para o G3, enquanto que os demais grupos não apresentaram diferença significante para o subcontorno (p> 0,05). Dentro das limitações do presente estudo, pode-se concluir que a técnica convencional após ponto de solda é uma alternativa viável para confecção de infraestruturas de próteses fixas de três elementos comparado ao uso de sistemas CAD/CAM, uma vez que as técnicas apresentaram valores de adaptação marginal vertical similares. Os sistemas CAD/CAM extraoral apresentou o maior desajuste horizontal (sobrecontorno) em comparação com outros grupos.

Retention System and Splinting on Morse Taper Implants in the Posterior Maxilla by 3D Finite Element Analysis

Abstract The purpose of this study was to evaluate different retention systems (cement- or screw-retained) and crown designs (non-splinted or splinted) of fixed implant-supported restorations, in terms of stress distributions in implants/components and bone tissue, by 3-dimensional (3D) finite element analysis. Four 3D models were simulated with the InVesalius, Rhinoceros 3D, and SolidWorks programs. Models were made of type III bone from the posterior maxillary area. Models included three 4.0-mm-diameter Morse taper (MT) implants with different lengths, which supported metal-ceramic crowns. Models were processed by the Femap and NeiNastran programs, using an axial force of 400 N and oblique force of 200 N. Results were visualized as the von Mises stress and maximum principal stress (σmax). Under axial loading, there was no difference in the distribution of stress in implants/components between retention systems and splinted crowns; however, in oblique loading, cemented prostheses showed better stress distribution than screwed prostheses, whereas splinted crowns tended to reduce stress in the implant of the first molar. In the bone tissue cemented prostheses showed better stress distribution in bone tissue than screwed prostheses under axial and oblique loading. The splinted design only had an effect in the screwed prosthesis, with no influence in the cemented prosthesis. Cemented prostheses on MT implants showed more favorable stress distributions in implants/components and bone tissue. Splinting was favorable for stress distribution only for screwed prostheses under oblique loading.

Resumo O objetivo deste estudo foi avaliar diferentes sistemas de retenção (cimentada x parafusada) e configuração da coroas (unitárias x esplintadas) de próteses fixas implantossuportadas em relação a distribuição de tensões nos implantes/componentes e tecido ósseo pela análise de elementos finitos 3D. Quatro modelos 3D foram simulados com auxílio dos programas Invesalius, e Rhinoceros 3D, e SolidWorks. Os modelos foram confeccionados simulando bloco ósseo de região posterior da maxila (tipo ósseo III), com 3 implantes cone Morse com 4,0 mm de diâmetro e diferentes comprimentos, suportando prótese metalocerâmica de 3 elementos. Os modelos foram processados pelos programas FEMAP e NEiNastran sob força axial de 400 N e oblíqua de 200N. Os resultados foram plotados através de mapas de tensão de von Mises (vM) (implantes e componentes) e tensão máxima principal (TMP) (tecido ósseo). Sobre o carregamento axial, não foi observada diferenças entre os diferentes sistemas de retenção e tipo de prótese na distribuição das tensões nos implantes/componentes, porém, sobre o carregamento oblíquo as próteses cimentadas apresentaram melhor distribuição de tensões em comparação com as próteses parafusadas, enquanto que as próteses esplintadas apresentou uma tendência de redução das tensões no implante do primeiro molar. No tecido ósseo as próteses cimentadas apresentaram melhor distribuição das tensões em comparação com as próteses parafusadas, independente do carregamento. A esplintagem foi favorável somente para as próteses parafusadas, não havendo influência sobre as próteses cimentadas. As próteses cimentadas sobre implantes cone Morse apresentam melhor comportamento biomecânico nos implantes/componentes e tecido ósseo. A esplintagem foi efetiva somente nas próteses parafusadas sob carregamento oblíquo.

Three-Dimensional Finite Element Analysis of Varying Diameter and Connection Type in Implants with High Crown-Implant Ratio

Abstract The aim of this study was to evaluate the effect of varying the diameter, connection type and loading on stress distribution in the cortical bone for implants with a high crown-implant ratio. Six 3D models were simulated with the InVesalius, Rhinoceros 3D 4.0 and SolidWorks 2011 software programs. Models were composed of bone from the posterior mandibular region; they included an implant of 8.5 mm length, diameter Ø 3.75 mm or Ø 5.00 mm and connection types such as external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Models were processed using the Femap 11.2 and NeiNastran 11.0 programs and by using an axial force of 200 N and oblique force of 100 N. Results were recorded in terms of the maximum principal stress. Oblique loading showed high stress in the cortical bone compared to that shown by axial loading. The results showed that implants with a wide diameter showed more favorable stress distribution in the cortical bone region than regular diameter, regardless of the connection type. Morse taper implants showed better stress distribution compared to other connection types, especially in the oblique loading. Thus, oblique loading showed higher stress concentration in cortical bone tissue when compared with axial loading. Wide diameter implant was favorable for improved stress distribution in the cortical bone region, while Morse taper implants showed lower stress concentration than other connections.

Resumo O objetivo deste estudo foi avaliar o efeito da variação do diâmetro e dos tipos de conexão na distribuição do estresse no osso cortical para implantes com a proporção coroa-implante. Seis modelos 3D foram simulados com os programas InVesalius, Rhinoceros 3D 4.0 e SolidWorks 2011. Os modelos foram compostos de osso da região mandibular posterior. Foram incluídos implantes de 8,5 mm de comprimento, diâmetro Ø 3,75 mm ou Ø 5,00 mm, e tipos de conexão como hexágono externo (EH), hexágono interno (IH) e cone Morse (MT). Os modelos foram processados usando os programas Femap 11.2 e NeiNastran 11.0 e usando uma força axial de 200 N e força oblíqua de 100 N. Os resultados foram registrados em termos da tensão principal máxima. O carregamento oblíquo mostrou alta tensão no osso cortical em comparação com a carga axial. Os resultados mostraram que os implantes com maior diâmetro apresentaram distribuição de tensões mais favorável, independentemente do tipo de conexão, enquanto que os implantes cone Morse apresentaram melhores distribuição de tensões comparado aos outros tipos de conexão, especialmente no carregamento oblíquo. Assim, os implantes de maior diâmetro foram mais favoráveis para distribuição das tensões na região de tecido ósseo cortical, enquanto que os implantes cone Morse apresentam menores concentrações de tensões do que as outras conexões.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria.

OBJECTIVE: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. MATERIAL AND METHODS: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in µCT were obtained to calculate bone mineral density (BMD). RESULTS: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The µCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). CONCLUSION: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Medication-related osteonecrosis of the jaw, osteoradionecrosis, and osteomyelitis: A comparative histopathological study

Abstract It is largely known that some oral diseases can be diagnosed based upon their clinical manifestation combined with the patient's medical history and generally not depending on examination. This is the case of some bone diseases such as osteoradionecrosis of the jaw (ORNJ), osteomyelitis of the jaw (OMJ), and medication-related osteonecrosis of the jaw (MRONJ). The present study aimed to analyze the histopathological features of these specific bone diseases in order to evaluate similarities and differences. Forty-four bone specimens resected from each bone disease (22 cases of ORNJ, 6 cases of OMJ, and 16 cases of MRONJ) were analyzed by two experienced oral pathologists without prior knowledge of the diagnosis, considering bone tissue condition, inflammation, vascularization, and the presence of microorganisms. In addition, the examiners formulated a diagnostic hypothesis for each specimen. Many histopathological similarities were found among the diseases, especially considering the presence of necrotic bone, inflammation, and microorganisms. Statistically significant differences were detected in empty bone lacunae, which was decreased in ORN (p = 0.042), and considering neutrophil count, which was low in the MRONJ group (p ≤ 0.001). The Kappa coefficient was calculated and agreement was detected based on the histopathological parameters, but not for diagnostic suggestion (p=0.23). In conclusion, histopathological aspects of ORNJ, OMJ, and MRONJ do not permit a conclusive diagnosis, emphasizing the necessity of a detailed clinical report.