Ageism in dental students - a multicentric study in southern Brazil.

OBJECTIVES: Gerontological education and intergenerational contact are proven strategies for effectively combating ageism. In this context, this study investigates the association between gerontological education, intergenerational contact, and ageism among dental students. METHODS: Gerontological education from students' perspective, intergenerational contact, and ageism were assessed using a questionnaire containing sociodemographical aspects and an ageism scale (ASDS-Braz). The sample included students enrolled in the final year of dental programs at three public universities in southern Brazil. A multilevel Poisson regression was conducted to assess factors associated with ASDS-Braz scores. RESULTS: A modest correlation was identified between dental schools in terms of reducing ageism, and a weak correlation was found between self-reported race and ageism. Notably, statistically significant findings were observed across family relationship with older individuals: students who reported having a poor relationship with older adults in their families presented 45% higher ageism scores than did those with an excellent relationship. CONCLUSION: The results suggested that while some gerontological education was reported by the participants, it may not be sufficient to prepare dental students to provide effective oral healthcare to older adults and to reduce ageism among them. Additionally, reinforcing positive aspects of intergenerational relationships may be an additional strategy in combating ageism within this population.

Effect of radiotherapy, immediate dentin sealing and irrigation simulating single- or two-visits endodontic treatment on the bond strength to pulp chamber dentin: an in vitro study.

This study aimed to evaluate the influence of radiotherapy and different endodontic treatment protocols on the bond strength to pulp chamber dentin. Eighty mandibular molars were randomly divided into two groups (n = 40): non-irradiated and irradiated (60 Gy). The pulp chambers were sectioned, and each group was subdivided (n = 8), according to the endodontic treatment protocol: no treatment (Control); Single-visit; Two-visits; Immediate dentin sealing (IDS) + single-visit; and IDS + two-visits. Each endodontic treatment visit was simulated through irrigation with 2.5% NaOCl, 17% EDTA and distilled water. IDS was performed by actively applying two coats of a universal adhesive to the lateral walls of the pulp chamber. After, the pulp chambers were restored with resin composite and four sticks were obtained for microtensile test. In addition, the dentin of the pulp chamber roof was assessed for surface roughness, chemical composition, and topography after each treatment protocol. Two-way ANOVA, Tukey's post hoc, Mann-Whitney, Kruskal-Wallis and Dunn's post hoc were performed (α = 5%). The treatment protocol affected bond strength (p < 0.05), while the irradiation did not (p > 0.05). The control group presented the highest values (p < 0.05). The single-visit group demonstrated better performance compared to the other groups (p < 0.05), which did not differ from each other (p > 0.05) The use of IDS changed the surface roughness (p < 0.05), chemical composition (p < 0.05) and topography of the dentin. In conclusion, the treatment protocol influenced dentin adhesion, while irradiation did not.

Effect of erosive conditions on different sealant materials used in paediatric dentistry.

To evaluate the effect of acidic challenge on erosion depth and topographic characteristics of different materials used as occlusal sealants. Two hundred specimens of five sealant materials (Fuji IX, Ketac Molar, Fuji II, Equia and Clinpro) and forty bovine teeth enamel samples (control) were prepared and exposed to acidic challenge. The specimens were immersed in four different solutions (orange juice, coke drink, citric acid or distilled water) under mildly shaken conditions for 3 days. The erosion depth profiles were measured using a profilometer and Scanning Electron Microscope (SEM). Two-way ANOVA with Tukey post-hoc test was performed to evaluate the interactions. Sealant material and acidic challenge had significant effects on erosion depth. Among the materials, Fuji II presented the highest mean of erosion depth after immersion in orange juice, coke drink, and citric acid. All materials groups presented higher erosion depth values after immersion in the citric acid solution, except Clinpro. Bovine enamel presented higher erosion depth values compared to all materials when submitted to erosive challenge. Sealant materials submitted to the acidic challenge presented different degrees of erosion and topographic modification; however, they are less susceptible to erosion than bovine teeth enamel.

Influence of CAD-CAM milling strategies on the outcome of indirect restorations: A scoping review.

STATEMENT OF PROBLEM: The influence of computer-aided manufacturing (CAM) parameters and settings on the outcomes of milled indirect restorations is poorly understood. PURPOSE: The purpose of this scoping review was to summarize the current CAM systems, parameters, and setting changes, and their effects on different outcomes of milled indirect restorations and aspects related to their manufacture. MATERIAL AND METHODS: The protocol of this review is available online (https://osf.io/x28ps/). Studies that used at least 2 different parameters (CAM units, number of axes, digital spacers, or protocols with different rotatory instruments, grit-sizes, milling speed, or others) for milling indirect restorations were included. A structured search up to July 2023 was performed by 2 independent reviewers for articles written in English in LILACS, MEDLINE via PubMed, EMBASE, Web of Science, and Scopus. RESULTS: Of 1546 studies identified, 22 were included in the review. Discrepancies were found between the planned and actual measured cement space, with a decreasing linear relationship impacting restoration adaptation at different points. The CEREC MC XL milling machine was the most used system in the included studies, with variations in bur types, milling modes, and number of burs uses affecting internal fit and surface trueness. The results demonstrated the better adaptation of restorations made with 5-axis over 3-axis milling machines. Lithium disilicate and zirconia were the most commonly used materials, and crowns and inlays were popular designs. Marginal and internal adaptation were the primary outcomes assessed using the various techniques. CONCLUSIONS: The study presented a comprehensive exploration of CAM systems and parameters, and their influence on indirect restorations. The planned cement space was not properly reproduced by the milling. Bur characteristics can affect restoration fit and trueness. The 5-axis units seem to result in better-adapted restorations compared with 3- and 4-axis units.

Effect of erosive conditions on different sealant materials used in paediatric dentistry

Abstract To evaluate the effect of acidic challenge on erosion depth and topographic characteristics of different materials used as occlusal sealants. Two hundred specimens of five sealant materials (Fuji IX, Ketac Molar, Fuji II, Equia and Clinpro) and forty bovine teeth enamel samples (control) were prepared and exposed to acidic challenge. The specimens were immersed in four different solutions (orange juice, coke drink, citric acid or distilled water) under mildly shaken conditions for 3 days. The erosion depth profiles were measured using a profilometer and Scanning Electron Microscope (SEM). Two-way ANOVA with Tukey post-hoc test was performed to evaluate the interactions. Sealant material and acidic challenge had significant effects on erosion depth. Among the materials, Fuji II presented the highest mean of erosion depth after immersion in orange juice, coke drink, and citric acid. All materials groups presented higher erosion depth values after immersion in the citric acid solution, except Clinpro. Bovine enamel presented higher erosion depth values compared to all materials when submitted to erosive challenge. Sealant materials submitted to the acidic challenge presented different degrees of erosion and topographic modification; however, they are less susceptible to erosion than bovine teeth enamel.

Evaluation paste removal method and bond strength between resin cement and lithium disilicate ceramic: An in vitro study.

STATEMENT OF PROBLEM: After the use of evaluation paste, residue can remain on the bonding surface. However, how adhesion to lithium disilicate ceramic is affected is unclear. PURPOSE: The purpose of this in vitro study was to determine the effectiveness of lithium disilicate cleaning after contamination with an evaluation paste and before the application of a resin cement. MATERIAL AND METHODS: Rectangular lithium disilicate (IPS e.max CAD) specimens were obtained with a simulated milled surface, crystallized, etched with 5% hydrofluoric (HF) acid, and contaminated with an evaluation paste. The cleaning methods tested were air-water spray (SPRAY), 37% phosphoric acid (HPO), ultrasonic bath (ULT), cleaning paste (IVOC), and a conventional surface treatment (HF + silane-HF+SIL). The control (CTRL) group was not contaminated. After silane had been applied, resin cement cylinders were fabricated and light polymerized. Half of the cylinders (n=56) were tested for microshear bond strength at baseline (24 hours), and the other half after 210 days of water storage and 25 000 thermal cycles. Surface roughness, failure analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were performed. Statistical analysis was performed with the Kruskal-Wallis and Mann-Whitney tests for surface roughness and the 2-way ANOVA and Bonferroni post hoc tests for bond strength (α=.05). RESULTS: At baseline, only SPRAY did not restore the bond strength compared with CTRL. After aging, the bond strengths of SPRAY and IVOC were lower than of CTRL (P<.05); no significant difference was found between CTRL, HPO, ULT, and HF+SIL (P>.05). EDS demonstrated the presence of carbon in the SPRAY and ULT groups, probably remnants of the evaluation paste. SEM analysis identified such remnants in the SPRAY group only. CONCLUSIONS: For optimal bond strength between lithium disilicate and resin cement after evaluation paste use, cleaning the ceramic surface with 37% phosphoric acid, ultrasonic bath, or with hydrofluoric acid worked best.

Survival rate and treatment success of glass fiber posts cemented with two adhesive cementation strategies after up to 106 months: a randomized clinical trial.

OBJECTIVES: The objective of this study is to evaluate the longevity of two fiber post cementation strategies in a prospective, multicenter, non-inferiority, double-blind randomized controlled trial. METHODS: A total of 152 teeth, with adequate endodontic treatment and loss of coronal structure and bilateral simultaneous posterior occlusal contacts, were randomly allocated to receive glass fiber posts cemented with a conventional cementation strategy (CRC group: adhesive system + resin cement) (Adper Single Bond + RelyX ARC; 3 M-ESPE) or a self-adhesive cementation strategy (SRC group: self-adhesive resin cement; RelyX U100/U200; 3 M-ESPE). The patients were recalled annually for clinical and radiographical evaluation with a 93% recall rate (142 teeth, with 74 at CR groups and 68 at SRC group). The primary outcome was survival rate, considering the fiber post debonding (loss of retention). The secondary outcome included the success rate of the prosthetic treatment with crown debonding, post fracture, and tooth loss (not related to post failure). Both outcomes were evaluated annually. The Kaplan-Meier method and Cox regression with 95% confidence interval were used for the statistical analysis. RESULTS: For the primary outcome (failures directly related to fiber posts cementation strategy), there were 4 fiber post debondings (2 per group), 8 root fractures (3 for SRC group and 5 for CRC group), and one mixed failure (debonding combined with root fracture for CRC), with both strategies presenting similar survival rates (p = 0.331), with 88.9% for the CRC group and 90.9% for the SRC group. For the secondary outcome (failures not related to fiber post cementation strategies), there were 8 crown debondings, 3 post fractures, and 3 tooth losses, with no statistically difference between groups (p = 0.701), with 77% for SRC and 82% for CRC. CONCLUSION: Fiber post cementation strategies with conventional or self-adhesive resin cement presents similar tooth survival and success rates. TRIAL REGISTRATION: NCT01461239 CLINICAL RELEVANCE: Both adhesive cementation strategies led to high survival and success rates and are indicated for fiber post cementation, even after a long follow-up period (up to 106 months).

Resin cement coating reverts the machining damage on the flexural fatigue strength of lithium disilicate glass-ceramic.

This study evaluated the effect of resin cement coating with high and low viscosities on the flexural fatigue strength of machined lithium disilicate glass-ceramic. Discs (IPS e.max CAD; Ivoclar Vivadent) were prepared and divided according to the surface condition (machining [M]-CEREC inLab; and polishing [P]-laboratory procedures), resin cement coating (with or without), and cement viscosity (high [H] and low [L]). The ceramic bonding surface was etched/primed by a one-step primer application followed by resin cement application (Variolink N base + high or low viscosity catalyst; Ivoclar Vivadent). Biaxial flexural fatigue strength was evaluated on a piston-on-three-ball set by the step-test method (n = 15) (initial stress: 60 MPa; incremental steps: 20 MPa; 10,000 cycles/step, at 20 Hz). Weibull statistics were used for fatigue data. Contact angle, topographic, and fractographic analysis were also performed. Machining produced statistically lower contact angle than polishing and a significant detrimental effect on the fatigue behavior (σ0 M = 247.2 [246.9-268.3]; σ0 P = 337.4 [297.8-382.4]). Machined groups followed by resin cement coating (σ0 MH = 297.9 [276.0-321.5]; σ0 Ml = 301.2 [277.1-327.4]) behaved similarly to the polished and coated groups (σ0 PH = 342.0 [308.9-378.5]; σ0 PL = 357.3 [324.7-393.1]), irrespective of the cement viscosity. Therefore, cement coating has able to revert the detrimental effects of the machining on the fatigue strength of lithium disilicate glass-ceramic. High and low viscosity cements behaved similarly in the improvement of CAD-CAM lithium disilicate fatigue strength.

Longevity of metal-ceramic single crowns cemented onto resin composite prosthetic cores with self-adhesive resin cement: an update of a prospective analysis with up to 106 months of follow-up.

OBJECTIVES: To evaluate the longevity of metal-ceramic single crowns cemented onto resin composite prosthetic cores using a self-adhesive resin cement in a prospective clinical descriptive study. METHODS: A total of 152 teeth were endodontically treated and received resin composite prosthetic cores and metal-ceramic crowns cemented with a self-adhesive resin cement. The patients included in the sample were recalled for clinical and radiography evaluation in an up-to-106-month period after the final cementation procedures, with an average of 62 months of follow-up. 91.5% of the sample (142 teeth) were evaluated regarding the treatment survival rate, analyzed considering the loss of crown retention (crown debonding) and tooth loss as the primary outcome. In addition, post debonding, and root fracture occurrences were also recorded as secondary outcomes to evaluate the success rate of the prosthetic treatment. The aesthetic parameters were also evaluated according to the FDI criteria. The Kaplan-Meier method and Cox regression with 95% confidence interval were applied for the statistical analysis. RESULTS: Regarding the primary outcome, the metal-ceramic crowns cemented with self-adhesive resin cement presented a high survival rate (91.5%), with 8 crown debondings and 3 tooth losses (1 due to caries and 2 due to periodontal disease) occurring after the evaluation period. For secondary outcomes, 9 root fractures and 4 post debondings occurred, generating a success rate of 72%. All crowns had a score 1 on the FDI criteria, indicating that they were clinically excellent or very good regarding the aesthetic parameters. CONCLUSION: The metal-ceramic crowns luted with a self-adhesive resin cement presented a survival rate of 91.5% after an average of 62 months of follow-up. Furthermore, the restorations remained aesthetically satisfactory over time, without changes that would indicate prosthetic retreatment. A success rate of 72% was obtained considering the secondary outcome, mainly related to intraradicular retainer failures (root fractures or post debonding). CLINICAL SIGNIFICANCE: The self-adhesive resin cement is clinically indicated for cementation of metal-ceramic crowns onto resin composite prosthetic cores.

Translucency and masking ability of a translucent zirconia with different thicknesses over dark backgrounds / Translucidez e capacidade de mascaramento de uma zircônia translúcida com diferentes espessuras sobre substratos escuros

ABSTRACT Objectives: To evaluate the translucency, contrast ratio and masking ability of a translucent zirconia with different thicknesses. Methods: Disc shaped specimens (n= 3) with 10 mm (Ø) x 1.5 mm, 1 mm and 0.7 mm (thickness) were manufactured simulating all-ceramic simplified restorations. Substrate discs (n= 2; Ø: 10 mm; thickness: 2 mm) were simulated with composite resin shades: A2 (positive control) and C4; and metal alloys: silver (Ni-Cr) and golden (Cu-Al). Optical properties of the 9 translucent zirconia specimens placed on the 3 different substrates were analyzed by a spectrophotometer. The color variation (ΔE00) between each ceramic structure over the positive control substrate (A2) and over the dark backgrounds (C4, silvery, golden) were obtained as to their ceramic masking ability and subjected to non-parametric Kruskal Wallis test (5%). The translucency parameter (TP00) and contrast ratio (CR) of the different thicknesses of the ceramic discs were also collected and analyzed by one-way ANOVA and the Tukey test (5%). Results: The translucent zirconia showed greater opacity in the thickness of 1.5 mm, although it was not statistically different between 0.7 and 1.0 mm. All dark backgrounds significantly affected the final color of the simplified restoration in all evaluated thicknesses. However, the increase in ceramic thickness showed a decrease in ΔE00 values for all substrates. Conclusion: The translucent zirconia was not able to mask the dark substrates, independent of the evaluated thickness.

RESUMO Objetivos: Avaliar a translucidez, razão de contraste e capacidade de mascaramento de uma zircônia translúcida com diferentes espessuras. Métodos: Espécimes em forma de disco (n= 3) com 10 mm (Ø) x 1,5 mm, 1 mm e 0,7 mm (espessura) foram confeccionados simulando restaurações simplificadas em cerâmica pura. Discos de substrato (n= 2; Ø: 10 mm; espessura: 2 mm) foram simulados com as cores de resina composta: A2 (controle positivo) e C4; e ligas metálicas: prata (Ni-Cr) e ouro (Cu-Al). As propriedades ópticas dos 9 espécimes de zircônia translúcida posicionados nos 3 substratos diferentes foram analisadas por um espectrofotômetro. A variação de cor (ΔE00) entre cada espécime cerâmico sobre o substrato controle positivo (A2) e sobre os fundos escuros (C4, prateado, dourado) foi calculada quanto à capacidade de mascaramento da cerâmica e submetida ao teste não paramétrico de Kruskal Wallis (5%). O parâmetro de translucidez (TP00) e a razão de contraste (CR) das diferentes espessuras dos discos cerâmicos também foram coletados e analisados por ANOVA de uma via e teste de Tukey (5%). Resultados: A zircônia translúcida apresentou maior opacidade na espessura de 1,5 mm, embora não tenha sido estatisticamente diferente entre 0,7 e 1,0 mm. Todos os fundos escuros afetaram significativamente a cor final da restauração simplificada em todas as espessuras avaliadas. No entanto, o aumento da espessura da cerâmica mostrou uma diminuição nos valores de ΔE00 para todos os substratos. Conclusão: A zircônia translúcida não foi capaz de mascarar os substratos escuros, independente da espessura avaliada.

Fatigue behavior and stress distribution of molars restored with MOD inlays with and without deep margin elevation.

OBJECTIVES: This study evaluated the effect of deep margin elevation (DME) and restorative materials (leucite-reinforced glass-ceramics [C] vs. indirect resin composite [R]) on the fatigue behavior and stress distribution of maxillary molars with 2-mm deep proximal margins restored with MOD inlay. METHODS: Fifty-two extracted human third molars were randomly assigned into four groups (n = 13): C; DME + C; R; and DME + R. Inlays were fabricated in CAD-CAM and bonded to all teeth. The fatigue behavior was assessed with the stepwise stress test (10,000 cycles/step; step = 50 N; 20 Hz; initial load = 200 N). Fatigue failure loads and the number of cycles were analyzed with 2-way ANOVA and Tukey's test (p < 0.05) and Kaplan-Meier survival plots. The stress distribution was assessed with finite element analysis. The models were considered isotropic, linear, and homogeneous, and presented bonded contacts. A tripod axial load (400 N) was applied to the occlusal surface. The stress distribution was analyzed with the maximum principal stress criterion. RESULTS: For fatigue, there was no difference for DME factor (p > 0.05). For the material factor, the load and number of cycles for failure were statistically higher in the R groups (p < 0.05). The finite element analysis showed that resin composite inlays concentrated more stress in the tooth structure, while ceramic inlays concentrated more stress in the restoration. Non-reparable failures were more frequent in the resin composite inlays groups. CONCLUSIONS: DME was not negative for fatigue and biomechanical behaviors. Resin composite inlays were more resistant to the fatigue test, although the failure mode was more aggressive. CLINICAL SIGNIFICANCE: DME does not impair mechanical behavior. Resin composite inlays failed at higher loads but with a more aggressive failure mode.

Spectrophotometric analysis of dental bleaching after bonding and debonding of orthodontic brackets.

INTRODUCTION: The aim of this study was to evaluate the bleaching effect after aging simulation in teeth submitted to bonding and debonding of orthodontic brackets. MATERIALS AND METHODS: For this study, 90 human premolars were selected, and randomly divided into 6 groups: control, bleaching, and other 4 groups submitted to bleaching after bonding and debonding brackets using different methods. Color measurement of sample through the CIE L*a*b* system was performed in three moments: T1 - after brackets debonding, T2 - after staining cycling, and T3 - after bleaching. For evaluation of results among the components L*, a* and b*, the two criteria analysis of variance and the multiple comparison Tukey test (p < 0.05) were used. RESULTS: Statistically significant difference was observed among the groups submitted to brackets bonding and debonding through self-conditioning adhesive system and tungsten drill, also the control and bleaching groups between the moments T1 e T2. CONCLUSION: Bonding and debonding brackets methods tested in this study showed influence on the sample color change, and after the tooth bleaching process, only the group without brackets previous bonding achieved the color value presented before the staining and aging of samples in the brackets absence.

School environment and individual factors influence oral health related quality of life in Brazilian children.

The aim of this study was to verify the influence of school environment and individual factors on oral health related quality of life (OHRQoL) in a representative sample of Brazilian schoolchildren. A cross-sectional study was conducted with 1,134 12-year-old schoolchildren from Santa Maria, Southern Brazil. Clinical variables were obtained from examinations carried out by calibrated individuals. In addition, parents/guardians answered a semi-structured questionnaire about sociodemographic characteristics. Contextual variables were obtained from the city's official database, including the mean income of the neighborhood in which the school was located and the Basic School's Development Index (IDEB) of the school. The Brazilian version of the Child Perception Questionnaire (CPQ11-14) was used to access OHRQoL. Data analysis was conducted using multilevel Poisson regression. Children studying in schools with a higher classification on the IDEB presented a lower CPQ11-14 mean score (rate ratio 0.80, 95%CI 0.74-0.88) than those studying in schools with a lower IDEB. Regarding individual variables, children with carious cavities, malocclusion, and gingival bleeding presented higher CPQ11-14 mean values than their counterparts. The same was observed in children from families with low socioeconomic status. School environment, and individual clinical and socioeconomic factors were associated with schoolchildren's OHRQoL.

School environment and individual factors influence oral health related quality of life in Brazilian children

Abstract The aim of this study was to verify the influence of school environment and individual factors on oral health related quality of life (OHRQoL) in a representative sample of Brazilian schoolchildren. A cross-sectional study was conducted with 1,134 12-year-old schoolchildren from Santa Maria, Southern Brazil. Clinical variables were obtained from examinations carried out by calibrated individuals. In addition, parents/guardians answered a semi-structured questionnaire about sociodemographic characteristics. Contextual variables were obtained from the city's official database, including the mean income of the neighborhood in which the school was located and the Basic School's Development Index (IDEB) of the school. The Brazilian version of the Child Perception Questionnaire (CPQ11-14) was used to access OHRQoL. Data analysis was conducted using multilevel Poisson regression. Children studying in schools with a higher classification on the IDEB presented a lower CPQ11-14 mean score (rate ratio 0.80, 95%CI 0.74-0.88) than those studying in schools with a lower IDEB. Regarding individual variables, children with carious cavities, malocclusion, and gingival bleeding presented higher CPQ11-14 mean values than their counterparts. The same was observed in children from families with low socioeconomic status. School environment, and individual clinical and socioeconomic factors were associated with schoolchildren's OHRQoL.