Do tooth-supported zirconia restorations present more technical failures related to fracture or loss of retention? Systematic review and meta-analysis.

OBJECTIVES: This systematic review was performed to determine the main cause of technical failure of tooth-supported zirconia crowns and fixed partial dentures (FPDs), categorizing them as fracture/chipping or loss of retention/decementation. MATERIALS AND METHODS: Electronic and manual searches were performed for randomized clinical trials, prospective clinical trials, and prospective cohort studies that reported the technical failure rates of zirconia restorations. The Cochrane Collaboration risk-of-bias tool and Newcastle-Ottawa scale were used to assess the quality of the studies. RESULTS: Fifty-two studies were included and most of them had unclear risk of bias. Considering all reported fractures/chipping, for veneered crowns with 1 to 3 years of follow-up, the relative risk (RR) of fracture in relation to loss or retention was 3.95 (95% CI 1.18-13.23; p = 0.03). For 4 to 6 years of follow-up, the RR was 5.44 (95% CI 1.41-20.92; p = 0.01). For veneered FPDs with 1 to 3 years of follow-up, the RR was 5.98 (95% CI 2.31-15.01; p = 0.0002). For 4 to 6 years of follow-up, the RR was 3.70 (95% CI 1.63-8.41; p = 0.002). For 7 years or more of follow-up, the RR was 3.45 (95% CI 1.84-6.46; p = 0.0001). When only framework fractures were considered, there were no significant differences for the RR in all follow-up periods (p > 0.05). CONCLUSIONS: Higher RR for fracture/chipping in relation to decementation for veneered zirconia crowns and FPDs at all follow-up times. For framework fractures, no difference was observed between the risk of failure of the restoration due to fracture or decementation. CLINICAL RELEVANCE: Zirconia crowns and FPDs showed relatively high success and survival rates. However, considering the technical failures, there is approximately four times higher chance of fracture/chipping than loss of retention for both single and multi-unit tooth-supported veneered zirconia restorations.

Effect of elastic gradients on the fracture resistance of tri-layer restorative systems.

OBJECTIVES: To assess the impact of elastic gradients formed among restorative material, cement, and substrate on the fracture resistance of tri-layer restorative systems. METHODS: Four CAD/CAM materials were utilized, two glass-ceramics (IPS e.max CAD, Vita Suprinity) and two resin-ceramic hybrids (Vita Enamic, Lava Ultimate). Their fracture resistance was examined by biaxial flexure (n = 8) and Hertzian indentation (n = 10) tests. Statistical analysis was conducted using ANOVA and Tukey tests (p = 5 %). Finite element analysis (FEA) was employed to simulate the Hertzian indentation test and elucidate the stress-fields formed on the intaglio surface below the loading area. RESULTS: The biaxial flexural strength (MPa) of glass-ceramics exceeded the hybrid materials (e.max 417a, Suprinity 230b, Enamic 138c, and Lava Ultimate 183bc). Conversely, the load-bearing capacity (N) of the materials bonded to dentin analog demonstrated the opposite trend, with the hybrid materials achieving superior results (e.max 830 C, Suprinity 660D, Enamic 1822B, and Lava Ultimate 2593 A). The stress-fields observed by FEA were coherent with the experimental results for Hertzian flexural stresses (MPa): e.max 501 A, Suprinity 342 C, Enamic 406B, whereas no tensile stress was observed at the intaglio surface of Lava Ultimate. SIGNIFICANCE: Detailed analysis of the fracture resistance of the tri-layer restorative systems showed that the elastic gradients play a more significant role than the flexural strength of the restorative materials. The coherence of the elastic moduli between the restorative material and supporting structures results in reduced tensile stress concentration at the intaglio surface beneath the loading area and enhances the ability to withstand load.

High-viscosity glass-ionomer cement or composite resin for restorations in posterior permanent teeth? A systematic review and meta-analyses.

OBJECTIVES: Answer the PICO question: Do class I and II posterior restorations in permanent teeth placed with high-viscosity glass-ionomer cement (HV-GIC) fail more than composite resin (CR) restorations? DATA: The study was registered in the PROSPERO database (CRD42020138290). Randomized and controlled clinical trials, comparing the performance of HV-GIC and CR in load bearing cavities of posterior permanent teeth were included. Cochrane risk of bias tool and GRADE were used to assess the quality and certainty of the evidence. Meta-analyses were performed for clinical outcomes on USPHS and FDI criteria for 12-, 24- and 36-months follow-ups. SOURCES: PubMed, Scopus and Web of Science were last searched on April 2, 2022, without language or date restrictions. Reference lists of primary studies and their related article link in PubMed were manually searched. STUDY SELECTION: Ten studies were included, while data from 8 were used for the meta-analyses. A total of 849 HV-GIC and 800 CR restorations were followed. The primary outcome was the fracture/retention of the restoration, with a comparable performance for both materials on all follow-ups. The 36 months follow-up for class I restorations (longest) showed risk difference of -0,00 (95%CI -0,03 to 0,03; p = 0,98) and no heterogeneity (p = 0,98, I2=0%). The certainty of the evidence is moderate, as all included studies were at an uncertain risk of bias. CONCLUSIONS: HV-GIC and CR presented comparable clinical performance in posterior permanent teeth up to 36 months. HV-GIV wear in class I restorations followed by 24 months was the only poorer result compared to CR. CLINICAL SIGNIFICANCE: Conservative load bearing cavities in permanent posterior teeth can be restored with HV-GIC with comparable clinical performance to CR expected at least up to 3 years. HV-GIC is a valuable direct restorative option for posterior teeth in high caries risk patients, in which CR is frequently associated with failure.

Postsurgical infection after myelomeningocele repair: a multivariate analysis of 60 consecutive cases.

OBJECTIVE: We investigate the demographic, clinical and surgical variables associated with wound and ventriculoperitoneal (VP) shunt infections in a well-defined group of patients submitted to neurosurgical myelomeningocele repair. METHODS: We analyzed the data of sixty consecutive patients with a myelomeningocele diagnosis submitted to neurosurgical repair between January 2002 and December 2005. Multiple logistic regression analysis identified clinical, demographic and neurosurgical variables that were independently associated with the occurrence of wound and VP shunt infections. RESULTS: Seven patients (11.7%) developed wound infections after myelomeningocele repair and two (3.3%) presented with sepsis unrelated to the neurosurgical procedures. Forty-six patients (76.7%) received a VP shunt and nine of them (19.6%) had VP shunt infection. There was a non-significant trend (p=0.09) for a higher association between thoracic than lumbar or sacral topography and the occurrence of any type of infection. Among patients who underwent VP shunt placement, there was a non-significant trend for a higher association between VP shunt infection and thoracic topography compared to lumbar or sacral regions (adjusted OR 4.3; CI 95% 0.7-24.7; p=0.10). Evans' index scores higher than 70 were ten times more associated with VP shunt infection (adjusted OR 10.5; CI 95% 1.6-67.4; p=0.01) than lower scores. CONCLUSION: The thoracic topography of myelomeningocele has a trend for a higher association with infection in general and VP shunt infection. Evans' index scores higher than 70 were independently associated with VP shunt infection.

Avaliação da resistência de união em dentina humana submetida a diferentes formas de armazenagem / Evaluation of bond strength of human dentin subjected to different forms of storage

.Introdução e objetivo: Dentes humanos são frequentemente utilizados em atividades laboratoriais e nas pesquisas científicas. O objetivo deste estudo foi avaliar a resistência de união em dentina humana submetida a diferentes formas de armazenagem. Material e métodos: Foram selecionados 15 terceiros molares hígidos, divididos em três grupos experimentais (n = 5): 1) esterilizados em autoclave por 15 minutos (121°C) e congelados em água destilada por 60 dias; 2) imersos em solução de glutaraldeído 2% por 24 horas e congelados em água destilada por 60 dias; 3) somente congelados em água destilada por 60 dias (controle). As amostras foram preparadas com disco diamantado sob refrigeração para obtenção de superfícies planas de dentina média, que sofreram a ação de lixas de carbeto de silício n.º 600 para criar lama dentária previamente à hibridização. O sistema adesivo convencional Adper Single Bond 2 e o compósito Filtek Z250 (3M Espe) foram utilizados de acordo com as instruções dos fabricantes. Matrizes transparentes Tygon foram posicionadas sobre cada amostra de dentina hibridizada e preenchidas em seu volume interno com o compósito. Após fotoativação, removeram-se as matrizes e expuseram-se os corpos de prova, que foram armazenados em água destilada a 37°C por 24 horas antes do ensaio de resistência de união ao microcisalhamento. Resultados: A resistência de união foi calculada em MPa±DP, e os dados foram analisados estatisticamente pela Anova e pelo teste de Tukey no nível de 5% de significância. As informações obtidas mostraram que o grupo controle apresentou resistência de união estatisticamente superior aos demais grupos experimentais. Conclusão: A esterilização em autoclave e a imersão em solução de glutaraldeído reduziram de modo significativo a resistência de união em dentina humana, quando se comparou aos dentes armazenados em água destilada congelada.

Introduction and objective: Human teeth are frequently used in laboratory and research activities. The aim of this study was to evaluate the bond strength of human dentin subjected to different forms of storage. Material and methods: Fifteen intact third molars were selected and divided into three experimental groups (n = 5): 1) teeth sterilized by autoclave for 15 minutes (121°C) and frozen in distilled water for 60 days; 2) teeth immersed in 2% glutaraldehyde solution for 24 hours and frozen in distilled water for 60 days; 3) only frozen in distilled water for 60 days (control). Samples were prepared with a diamond disk under cooling until obtaining flat surfaces of middle dentin, which were exposed by wet abrasion with 600-grit SiC paper in order to create smear layer prior to hybridization. The conventional adhesive system Adper Single Bond 2 and the composite Filtek Z250 (3M Espe) were used according to manufacturer?s instructions. Tygon tubing molds were placed on each sample and its internal volume was filled with the composite. After photoactivation, the molds were removed and the specimens were exposed and stored in distilled water at 37°C for 24 hours before microshear bond strength test. Results: The bond strength was calculated in MPa±SD, and data were statistically analyzed by Anova and Tukey test at 5% significance level. Data showed that the control group presented bond strength statistically higher than the other experimental groups. Conclusion: The autoclaving and immersion in glutaraldehyde solution reduced significantly the bond strength in human dentin when compared to frozen teeth in distilled water.

Avaliação do nível de conhecimento dos acadêmicos do curso de Odontologia da UNIVILLE sobre a utilização de dentes extraídos na graduação e banco de dentes / Evaluation of the dentistry course of UNIVILLE students' knowledge about the use of the extracted teeth in the graduation and the teeth bank

Os objetivos deste estudo foram, por meio de um questionário, avaliar o nível de conhecimento dos alunos do curso de Odontologia da UNIVILLE sobre o banco de dentes, suas atividades e funcionamento, biossegurança na manipulação de dentes e, especialmente, descobrir o motivo pelo qual os acadêmicos não realizam a doação espontânea de dentes para o banco. Um questionário foi elaborado e aplicado aos alunos do primeiro ao quinto ano do curso com questões pertinentes ao banco de dentes, como a utilização de dentes nas disciplinas do curso, biossegurança e doação de elementos dentais. Após aplicação do questionário, constatou-se que todos os alunos entrevistados (100%) precisaram de elementos dentais extraídos para utilização no ensino pré-clínico; 84,2% relataram dificuldade na obtenção dos dentes solicitados nas disciplinas; com relação à biossegurança, 66,6% dos alunos afirmaram ter manipulado sem equipamento de proteção individual os dentes extraídos, mesmo sabendo que a polpa e tecidos periodontais podem apresentar patógenos sanguíneos transmissíveis ao ser humano. Concluiu-se que o principal motivo pelo qual os acadêmicos não participam efetivamente da doação de estoques particulares é o desconhecimento sobre atividades do banco de dentes, suas normas de procedimento, protocolos de doação e, principalmente, retirada de elementos dentais

The aim of this study was, through a questionnaire, evaluate the level of knowledge of the students from graduation in Dentistry course -UNIVILLE, about the teeth bank: its activities and functioning,biosecutity in teeth manipulation and, especially, to find out the reason why the students do not donate spontaneously extracted teeth to the bank. A questionnaire was elaborated and applied to the students from the first to the fifth year of graduation with pertinent questions about the teeth bank, such as the use of teeth in the disciplines of the course, biosecurity and donation of dental elements. After the questionnaire was applied, it was possible to evidence that: all the interiewed students (100%) had needed extracted dental elements touse in laboratory assignments; 84,2% have reported difficulty in the obtainment of the requested teeth; about biosecurity, 66.6% of the students have stated that they had already manipulated extracted teeth without individual protection equipment; even knowing that the pulp and periodontal tissues can present sanguineous pathogenic microorganisms transmissible to the human being (86,8%). It was evidenced that the main reason why students did not participate effectively in the donation of private supplies, is the unfamiliarity with the activities of the teeth bank, its norms of procedure, protocols of donation and, mainly, the with drawal of dental elements

Avaliação de diferentes tratamentos mecânicos de superfícies na resistência à tração de reparos em resina composta direta / Evaluation of different mechanical surface treatments in tensile strength of direct composite resin repairs

O objetivo deste estudo foi comparar o efeito de diferentes tratamentos mecânicos de superfície na resistência à tração de reparos em resina composta direta. Foram confeccionados 12 corpos de prova de resina composta na forma de halter para o grupo controle e 24 corpos de prova na forma de hemi-halter para os demais grupos experimentais. Os corpos de prova foram armazenados por 30 dias em saliva artificial, antes da realização do procedimento de reparo. Os grupos experimentais foram reparados após tratamento mecânico da superfície, por intermédio da realização de retenções mecânicas, como também após o jateamento da superfície com partículas de óxido de alumínio. Depois do tratamento mecânico da superfície, a área de reparo foi condicionada com ácido fosfórico 37%, e o agente adesivo foi utilizado sem fotopolimerização prévia à adição do material reparador. Após o teste de resistência à tração, observou-se que o grupo reparado, por meio da realização de retenções mecânicas, apresentou resistência à tração significativamente inferior à força coesiva do material, enquanto entre os grupos reparados não foram observadas diferenças estatísticamente significativas. Com base nos resultados, foi possível concluir que o jateamento da superfície proporcionou reparos em resina composta direta com valores de resistência similares à força coesiva do material

The aim of this study was to compare the effect of different mechanical surface treatments in the tensile strength of direct composite resin repairs.12 specimens were obtained in halter form, for the control group, and 24in hemi-halter form for the other experimental groups. The specimens were stored for 30 days in artificial saliva before being repaired. The experimental groups were repaired after the mechanical surface treatment,through the mechanical retentions in the repairing surface, and also after the surface roughening with an air abrasion system. After mechanical treatment, the surface was etched with phosphoric acid and the adhesive system was used without a previous photo polymerizing to the repair material addition. After the tensile strength test it was observed that the group treated by macro-mechanical retentions presented significantly inferior strength values compared to the control group. More over, there were not observed significant differences among repaired groups,regardless mechanical surface treatment. Based on the results it was possible to conclude that air abrasion provided strength values incomposite resin repairs similar to cohesive strength.

Reparo em resina composta indireta: avaliação do tratamento mecânico da superfície / Indirect composite resin repair: surface mechanical treatment analysis

O objetivo deste estudo é comparar o efeito do tratamento macro e micromecânico da superfície na resistência à tração de reparos em resina composta indireta. Corpos de prova de resina ocmposta pós-polimerizada foram confeccionados inteiros para o grupo controle e pela metade para os grupos experimentais. Os corpos de prova foram armazenados por 30 dias em saliva artificial antes da realização do tratamento de superfície. O tratamento macromecânico foi feito com pontas diamantadas esféricas, e o micromecânico, por intermédio do jateamento da superfície com partículas de óxido de alumínio por 10 segundos. Após condicionamento da superfície com ácido fosfórico 37%, o agente adesivo foi utilizado sem fotopolimerização antes da adição do material reparador. Após o teste de resistência à tração, observou-se que a resistência dos reparos foi sempre inferior à força coesiva do material, mas estatisticamente inferior somente no grupo que recebeu retenções macromecânicas. Comparando os tratamentos de superfície, o grupo que sofreu jateamento com partículas de óxido de alumínio apresentou valores de resistência à tração estatisticamente superiores ao grupo que recebeu retenções macromecânicas. Com base nos resultados é possível concluir que o jateamento da superfície proporciona reparos em resina composta indireta com melhores valores de resistência.

O paciente geriátrico e a complexidade de seu atendimento / The geriatric patient and his complex attendance

Em meio ao crescimento desordenado da populaçäo idosa, no Brasil, cresce uma nova modalidade na área de saúde, a gerontologia. Além de descobrirem que tais pacientes necessitam de cuidados especiais, vários dentistas estäo optando por investigar formas mais precípuas de atender esta clientela, que poderá se tornar o público-alvo mais recorrente nas clínicas e consultórios dentários