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1.
Sleep Med ; 101: 461-467, 2023 01.
Article in English | MEDLINE | ID: mdl-36516603

ABSTRACT

OBJECTIVE: This study aimed to evaluate the influence of the frequency of rhythmic masticatory muscle activity per hour (RMMA/h) scored by polysomnography (PSG) recordings on sleep-related factors and orofacial pain symptoms. METHODS: According to RMMA/h frequency, participants were assigned either to the control group (i.e., CRMMA, n = 40); or the case group according to high (i.e., HRMMA, n = 12) or low (LRMMA, n = 28) RMMA/h frequency. Fisher's exact (nominal variables), One-way Analysis of Variance followed by post-hoc Tukey (continuous variables) and Poisson Regression tests were used to calculate orofacial pain symptoms and sleep-related breathing, behavior, and architecture differences between controls versus cases at a significance level of 5%. RESULTS: The CRMMA differed from HRMMA and LRMMA subgroups considering orofacial pain, self-reported tooth clenching or grinding, obstructive sleep apnea (OSA), snoring, and most variables considering sleep architecture (P ≤ 0.05). Multivariate adjusted Poisson regression analysis revealed that bruxers, regardless of RMMA/h frequency, presented a significantly higher prevalence rate (PR) related to orofacial pain (PR 1.68; P = 0.025) and self-reported behavior (PR 1.71; P = 0.012). CONCLUSION: Significant differences in N1, N2 and N3 stages, arousals, arousal per hour, and sleep onset latency variables were found comparing bruxer with high or low RMMA/h frequency. Compared to controls, bruxers presented higher PR related to headache and self-reported tooth clenching or grinding.


Subject(s)
Sleep Bruxism , Humans , Polysomnography , Case-Control Studies , Sleep Bruxism/complications , Sleep Bruxism/diagnosis , Sleep , Masticatory Muscles/physiology , Facial Pain/complications
2.
Gen Dent ; 70(5): 67-73, 2022.
Article in English | MEDLINE | ID: mdl-35993937

ABSTRACT

This in vitro study evaluated the effects of preheating, ultrasound application, and composite resin luting agent composition on the optical characteristics of feldspar ceramic laminates. The hypothesis was that the optical properties of the ceramic-luting agent-substrate unit would be affected by the composition of the luting material and use of ultrasound. Preheated restorative composite resins Charisma, IPS Empress Direct, and Filtek Z350 were used, with unheated RelyX Veneer resin cement serving as the control. The response variables for the physical properties of the materials were degree of conversion (n = 3 per material) and viscosity (n = 3 per material). Seven groups were generated based on the tested luting agent and the use of ultrasound. Color parameters were evaluated with a spectrophotometer at 3 timepoints (before luting [baseline], 24 hours after luting, and 1 month after luting), and color change was calculated according to the Commission Internationale de l'Eclairage (CIE) CIEDE 2000 formula and translucency parameters. The statistical significance of color change and viscosity was measured using 2-way analysis of variance (ANOVA), while the degree of conversion was measured using 1-way ANOVA. For translucency parameters, ANOVA on ranks and post hoc Duncan multiple range tests were performed. The control group showed the highest degree of conversion, while Filtek Z350 showed the highest viscosity. Statistically significant differences in color change between luting material groups were found under most conditions (P < 0.001), but there was no difference in translucency parameters between the luting materials (P = 0.446). Overall, the use of preheated composite resins as luting agents offers similar to poorer performance than conventional resin cement.


Subject(s)
Composite Resins , Resin Cements , Ceramics/chemistry , Color , Composite Resins/chemistry , Composite Resins/therapeutic use , Dental Cements/chemistry , Dental Porcelain/chemistry , Humans , Materials Testing , Resin Cements/chemistry , Resin Cements/therapeutic use , Surface Properties
3.
Dent Mater J ; 41(3): 451-458, 2022 May 31.
Article in English | MEDLINE | ID: mdl-35370258

ABSTRACT

This study investigated the effect of ultrasound application when luting ceramic using two preheated composites that show distinct responses to preheating at 69°C: Filtek Z100 and Z350XT. RelyX Veneer was the control. Feldspar disks were luted using the resin-based luting agents (RBLAs), and ultrasound was tested. Biaxial flexure strength (σbf) was calculated at z-axial positions of the luted disks (z=0; z=-t2). Microtensile bond strength (µTBS) to ceramic was tested (n=30). Data were analyzed at α=0.05. At z=0, the σbf was higher for Z350 when ultrasound was not used. When ultrasound was applied, the σbf was similar between Z350 and Z100. At z=-t2, differences across the RBLAs were observed: Z350 was superior than Z100 and control without ultrasound. Ultrasound increased σbf for Z100 at both axial positions. The preheated composites yielded higher µTBS than the control. Ultrasonication increased the mechanical performance of ceramic luted with Z100 without influencing the film thickness.


Subject(s)
Dental Bonding , Dental Cements , Ceramics/chemistry , Composite Resins/chemistry , Dental Cements/chemistry , Dental Porcelain/chemistry , Materials Testing , Resin Cements/chemistry , Surface Properties
5.
Clin Oral Investig ; 26(4): 3429-3446, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35291030

ABSTRACT

OBJECTIVES: This systematic review compared minimally and invasive surgical procedures to manage arthrogenous temporomandibular joint (TMJ). MATERIALS AND METHODS: The review included clinical trials assessing surgical procedures of arthrogenous temporomandibular disorder (TMD) management by carrying out comparisons within the same surgical procedure (pre- and post-treatment) as well as between different surgical procedures. Meta-analyses were conducted only for similar comparison reporting the same outcome measures, visual analog scale (VAS) values to evaluate pain and maximum incisal opening (MIO) values. RESULTS: Of the 1,015 studies identified by the search strategy, 26 were selected for full-text reading, and 19 were included in the review. Of these, 16 studies were included in the meta-analysis and 3 in the qualitative analysis. The VAS scores showed significantly lower values after discectomies (p < 0.001) and discoplasties (p < 0.001) in the within-group comparison. Moreover, significantly lower VAS scores and higher MIO values were observed after discectomy compared to arthroscopy, eminectomy, and discoplasty (p < 0.05). CONCLUSION: The findings of this systematic review suggest that although significantly lower VAS scores and higher MIO values were observed after discectomy, the currently available scientific evidence is unclear, and the use of invasive surgical procedures should not be implemented as an efficient first-line treatment option for arthrogenous TMD management. CLINICAL SIGNIFICANCE: VAS and MIO outcomes could be insufficient to describe the success or failure of open surgical procedures like discectomy and discoplasty.


Subject(s)
Temporomandibular Joint Disorders , Arthroscopy/methods , Humans , Pain , Range of Motion, Articular , Retrospective Studies , Temporomandibular Joint/surgery , Temporomandibular Joint Disorders/surgery , Treatment Outcome
6.
Clin Oral Investig ; 26(4): 3383-3393, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35149906

ABSTRACT

OBJECTIVES: This systematic review investigated the hypothesis that preheated resin composites (RCs) used as luting agents improve the mechanical properties, physicochemical performance, and color of indirect ceramic restorations. MATERIALS AND METHODS: Literature search was performed in three databases (Medline/PubMed, Scopus, and Web of Science) and in the grey literature (OpenGrey, ProQuest, and Catalog of Theses & Dissertations from CAPES). Eligibility criteria included only studies comparing at least one preheated RC used as a luting agent with resin cements. RESULTS: Data regarding the mechanical properties, physicochemical characteristics, and color were analyzed qualitatively, and the microtensile bond strength and film thickness were also evaluated by meta-analysis. The search strategy identified 3894 papers, and 28 were full-text screened. Seven studies were included in the review, and 5 were included in the meta-analysis. No significant difference was found for microtensile bond strength (P = 0.14). Preheated RCs showed significantly higher film thickness than resin cements (P = 0.001). CONCLUSION: Overall, the use of preheated RCs as luting agents offers similar to poorer performance than using resin cements for bonding indirect restorations. CLINICAL RELEVANCE: Despite the claim that preheated RC could be used as a luting agent, further studies should investigate the effect of clinically unacceptable film thickness.


Subject(s)
Dental Bonding , Dental Cements , Composite Resins/chemistry , Dental Cements/chemistry , Materials Testing , Resin Cements/chemistry , Surface Properties
7.
Eur J Oral Sci ; 129(2): e12765, 2021 04.
Article in English | MEDLINE | ID: mdl-33455026

ABSTRACT

This in vitro study evaluated the influence of feldspathic ceramic thickness on the properties of light- and dual-cured resin cements. For each cement (RelyX Veneer, Allcem Veneer, RelyX Ultimate, and Allcem Dual), three ceramic specimens were prepared, with seven thicknesses for each (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mm). The degree of conversion, Vickers microhardness, irradiance power, color variation (ΔE00 ), and translucency parameters were assessed. Microhardness and irradiance power were analyzed using analysis of variance (ANOVA) with post hoc Tukey's test, while ΔE00 , translucency parameters, and degree of conversion were analyzed using ANOVA of ranks with post hoc Duncan's Multiple Range Test. The relationship between each of the dependent variables (degree of conversion, ΔE00 , and translucency parameter tests) and the specimen thickness was described using linear regression for each of the four resin cements. The significance level for all analyses was set at 5%. RelyX Ultimate yielded the lowest degree of conversion values among all resin cements. Allcem Veneer produced the lowest microhardness values, without statistical differences between thicknesses, of up to 1 mm. Allcem Dual produced the highest ΔE00 and translucency parameter values. Feldspathic ceramic thickness influenced the mechanical properties of resin cements and optical aspects of the restorative set.


Subject(s)
Ceramics , Resin Cements , Aluminum Silicates , Dental Porcelain , Materials Testing , Potassium Compounds
8.
Dent Mater ; 36(10): 1356-1364, 2020 10.
Article in English | MEDLINE | ID: mdl-32888725

ABSTRACT

OBJECTIVE: This study investigated viscosity and thermal kinetics of 10 selected preheated restorative resin composites and the effect of ultrasound energy on film thickness. METHODS: A range of different resin composites was tested: Charisma Diamond, IPS Empress Direct, Enamel Plus HRi, Essentia, Estelite Omega, Filtek Z100, Filtek Z350 XT, Gradia, TPH Spectrum and VisCalor. A flowable resin composite (Opallis Flow) and two resin cements (RelyX Veneer, Variolink Esthetic LC) also were tested. Viscosity (Pa s) was measured at 37 °C and 69 °C (preheating temperature) using a rheometer. Film thickness (µm) was measured before and after application of ultrasound energy. Temperature loss within resin composite following preheating (°C/s) was monitored. Data were statistically analyzed (α = 0.05). RESULTS: Viscosity at 69 °C was lower than at 37 °C for all materials except the flowable resin composite. Preheating reduced viscosity between 47% and 92% for the restorative resin composites, which were generally more viscous than the flowable materials. Film thickness varied largely among materials. All preheated resin composites had films thicker than 50 µm without ultrasound energy. Application of ultrasound reduced film thickness between 21% and 49%. Linear and nonlinear regressions did not identify any relationship between filler loading, viscosity, and/or film thickness. All materials showed quick temperature reduction following preheating, showing maximum temperature loss rates after approximately 10 s. SIGNIFICANCE: Distinct restorative resin composites react differently to preheating, affecting viscosity and film thickness. The overall performance of the preheating technique depends on proper material selection and use of ultrasound energy for reducing film thickness.


Subject(s)
Composite Resins , Motion Pictures , Dental Enamel , Kinetics , Materials Testing , Resin Cements , Viscosity
9.
Sleep Med ; 70: 43-49, 2020 06.
Article in English | MEDLINE | ID: mdl-32193053

ABSTRACT

OBJECTIVE: This cross-sectional clinical study evaluated the associations between sociodemographic, occupational, clinical conditions, psychological and sleep quality variables on definite sleep bruxism (SB). METHODS: All records obtained from adults (aged 20-60 years) and the elderly (aged >60 years) who had undergone polysomnography (PSG) at a private medical outpatients' clinic from July 2017 to February 2018 were reviewed. Data from a questionnaire, based on the criteria of the American Academy of Sleep Medicine (AASM), were also gathered. Definite SB data pattern distribution was analyzed, and multivariate Poisson regression with robust variance was used to assess the associations between definite SB diagnosis, determined via PSG recordings, and the independent variables. A significance level of 5% was adopted. RESULTS: A total of 240 individuals were included in the study and the SB prevalence was 7.08% (n = 17). The adjusted Poisson regression analysis revealed association between definitive SB and individuals with respiratory allergy (PR = 3.63; 95% CI:1.01-13; P = 0.047) and restless sleep (PR = 2.97; 95% CI:1.04-8.50; P = 0.042). CONCLUSION: This study found associations between definite SB and clinical conditions (respiratory allergy) and sleep behavior (restless sleep). Knowledge regarding factors associated with definite SB can contribute to decision making in the clinical setting and management strategies involving a multidisciplinary approach.


Subject(s)
Hypersensitivity , Sleep Bruxism , Adult , Aged , Cross-Sectional Studies , Humans , Middle Aged , Polysomnography , Sleep , Sleep Bruxism/epidemiology , Young Adult
10.
Arch Oral Biol ; 112: 104685, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32097767

ABSTRACT

OBJECTIVE: This study evaluated the association between the diagnosis of sleep bruxism (SB), scored by way of polysomnographic (PSG) recordings, clinical conditions and sleep architecture. DESIGN: A case-control study was conducted. All records from adults who had undergone polysomnography (PSG) recordings at a private medical outpatient clinic between January 2015 and December 2017 were reviewed. The sample included 58 bruxers (case group) and 58 non-bruxers (control group), identified based on the PSG recording and matched by sex and age. RESULTS: Obese individuals had significantly lower chance (OR 0.18; 95 % CI: 0.05-0.62; P = 0.005) of an SB diagnosis than individuals with normal BMI. Alcohol consumption significantly increased (OR 2.74; 95 % CI: 1.11-6.78; P = 0.029) and OSA decreased the chances (OR 0.55; 95 % CI: 0.23-1.30; P = 0.173) of an SB diagnosis. Bruxers had a significantly shorter wake time after sleep onset (WASO) (p = 0.002). As far as non-rapid eye movement (NREM) is concerned, the duration of stage N1 was statistically shorter (p = 0.034) and the duration of stage N3 was statistically longer (p = 0.001) in bruxers. Arousals (p = 0.013), arousals per hour (p = 0.009), respiratory disturbance index (RDI) values (p < 0.0005) and the apnoea-hypopnea index (AHI) (p = 0.002) were all lower in bruxers than in non-bruxers. CONCLUSION: The results of this study support a significant association between SB diagnosis, BMI and alcohol consumption. SB modified the sleep architecture as statistically significant differences were found between bruxers and non-bruxers for WASO, NREM stage N1 and N3, arousals, arousals per hour, RDI and AHI.


Subject(s)
Sleep Bruxism , Sleep , Adult , Alcohol Drinking , Body Mass Index , Case-Control Studies , Female , Humans , Male , Middle Aged , Polysomnography , Risk Factors , Sleep Stages
11.
J Esthet Restor Dent ; 32(6): 569-574, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32043755

ABSTRACT

INTRODUCTION: This cross-sectional study evaluated the influence of endodontic filling material, cervical limit of root filling, and tooth location on the color variation (∆E00 ) from 1 to 60 months of follow-up. MATERIALS AND METHODS: Color records were obtained from 70 participants who received 83 endodontic treatments. CIEL*a*b* color coordinates were measured on the homologous tooth, which was considered as baseline, and on endodontic treated teeth with a spectrophotometer. ∆E00 was calculated by the CIEDE2000 method at three conditions (condition 1: homologous tooth vs endodontically treated tooth after ≤1 month; condition 2: homologous tooth vs endodontically treated tooth after >1-12 months; condition 3: homologous tooth vs endodontically treated tooth after >12 months up to 5 years) for each variable. The zinc oxide and eugenol mineral trioxide aggregate or resin-based filling materials, dental cervix or ≥2 mm in the apical direction cervical limit of root filling and anterior or posterior tooth location were considered in the comparisons. Confidence intervals for the means (95% CI) were calculated, ∆E00 values and CIEL*a*b* individual color coordinates were compared for each pair of variables using the Student t test or Welch test (α = .05). RESULTS: Greater ∆E00 values were generally observed in the condition 3 for cervical limit (∆E00 = 10.7), use of zinc oxide and eugenol and mineral trioxide aggregate-based filling materials (∆E00 = 10.7), and anterior teeth (∆E00 = 12.4). Only in the condition 1, the ∆E00 values of the filling materials did not show statistical differences (P = .198). CONCLUSIONS: Higher ∆E00 values were yielded from zinc oxide and eugenol and mineral trioxide aggregate-based filling materials, anterior teeth, and dental cervix cervical limit of root filling. CLINICAL SIGNIFICANCE: Tooth discoloration yielded by endodontic materials and procedures is a challenge to clinical practice resulting in aesthetic problems and discomfort to both patient and professional, especially when it occurs in anterior teeth.


Subject(s)
Root Canal Filling Materials , Tooth Discoloration , Tooth, Nonvital , Tooth , Cross-Sectional Studies , Drug Combinations , Female , Humans
12.
Braz. j. oral sci ; 19: e209398, jan.-dez. 2020. tab
Article in English | LILACS, BBO - Dentistry | ID: biblio-1177431

ABSTRACT

Aim: this study assessed the patients' perception of the outcomes of prosthetic treatment in a University of Southern Brazil. Methods: patients seeking for prosthetic treatment were invited to answer a questionnaire with 41 items about the potential risks, benefits, and consequences of no treatment. Answers were obtained according to a five-item Likert-scale varying from 1 (completely disagree) to 5 (completely agree). Sociodemographic data was included in the comparison. Mann-Whitney or Kruskal-Wallis (95%) compared data depending on the variable. Results: two-hundred twenty-five patients answered the questionnaire. Median age of participants was 45-54 years. The potential benefits were similar among participants irrespective of the variable adopted. The perception of risks was significant influenced by variables gender, age, education level, type of edentulous space, prior treatment with prosthodontics, type of prosthodontics, and prosthodontics usage in years. Consequences of no treatment were affected by age, prior treatment with prosthodontics, and prosthodontics usage in years. Conclusions: the study showed the fundamental importance of correct elucidation about the potential risks (negative perception) in the initial appointment for the studied population. Elucidation about the consequences of no treatment are relevant because some differences were seen into the variables. Prosthodontics patients from the city of Passo Fundo seem well informed about the benefits of the prosthetic treatment, besides the significant influence of some sociodemographic and prosthetic conditions


Subject(s)
Humans , Male , Female , Self Concept , Dental Prosthesis , Education, Dental , Surveys and Questionnaires
13.
J Prosthet Dent ; 122(6): 566.e1-566.e11, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31703919

ABSTRACT

STATEMENT OF PROBLEM: The inorganic filler of resin-based luting agents and the use of an adhesive layer could influence the bonding ability, mechanical performance, and interface morphology of bonded feldspathic ceramic. PURPOSE: The purpose of this in vitro study was to investigate the influence of resin-based luting agents loaded with different inorganic filler content, with or without an adhesive, on microtensile bond strength, biaxial flexural strength, and the adhesive interface morphology of bonded ceramic specimens. MATERIAL AND METHODS: Experimental resin-based luting agents with low (55wt%), intermediate (65wt%), and high (75wt%) filler contents were bonded to ceramic specimens, with or without a layer of adhesive. The resin-based luting agents were characterized by measuring viscosity, elastic modulus, Poisson ratio, and degree of conversion (n=3 for each test). The response variables for the bonded ceramic specimens were ceramic-resin microtensile bond strength (n=30), biaxial flexural strength (n=30) and characteristic strength, and Weibull modulus. Scanning electron microscopy was used for fractographic and interface analyses of the specimens fractured in the microtensile test (n=3). Data were subjected to ANOVA with the post hoc Tukey test (α=.05). Weibull moduli were also calculated. RESULTS: Increased inorganic filler content yielded significantly higher viscosity, stiffness, and film thickness. However, the Poisson ratio and degree of conversion were not affected. The lowest bond strength values were observed for the resin-based luting agents with high inorganic filler content when no adhesive was used and for the resin-based luting agent with low filler content when the adhesive was used. The increase in filler content of the resin-based luting agent appeared to be associated with a higher frequency of mixed failures. Increased filler content resulted in higher biaxial flexural and characteristic strength and decreased structural reliability. The adhesive helped fill irregularities on ceramic and slightly increased film thickness but had only a minor effect on mechanical strength. CONCLUSIONS: Experimental resin-based luting agent loaded with high inorganic filler content strengthened the bonded feldspathic ceramic and yielded significantly higher viscosity and film thickness. In contrast, the bond strength was lower if no adhesive was used.


Subject(s)
Dental Bonding , Dental Cements , Ceramics , Dental Porcelain , Materials Testing , Reproducibility of Results , Resin Cements , Surface Properties , Tensile Strength
14.
Dent Mater ; 35(10): 1430-1438, 2019 10.
Article in English | MEDLINE | ID: mdl-31387743

ABSTRACT

OBJECTIVE: This study evaluated the influence of preheating different composite resins on their viscosity and strengthening yielded to ceramic. METHODS: Modulus of elasticity, Poisson's ratio, and degree of CC conversion were measured for three restorative composite resins (Z100-microhybrid; Empress Direct-nanohybrid; Estelite Omega-supranano) and one photoactivated resin cement (RelyX Veneer). Viscosity was measured during a heating-cooling curve (25°C-69°C-25°C) and also using isothermal analyses at 25°C and 69°C. Feldspar ceramic disks simulating veneers were bonded with the luting materials. Biaxial flexural strength, characteristic strength, and Weibull modulus were calculated at axial positions (z=0 and z=-t2) of the bilayers. Film thickness was measured and morphology at the bonded interfaces was observed. Data were statistically analyzed (α=0.05). RESULTS: A gradual decrease in viscosity was noticed as the rheometer temperature gradually increased. Viscosity differences between the composite resins were large at the beginning of the analysis, but minor at 69°C. At 25°C, the composites were up to 38 times more viscous than the resin cement; at 69°C the difference was 5-fold. CC conversion was similar between all resin-based agents. The resin cement yielded lower film thickness than the composites. All resin-based agents were able to infiltrate the ceramic porosities at the interface and strengthen the ceramic. However, the magnitude of the strengthening effect was higher for the preheated composite resins, particularly at z=-t2. SIGNIFICANCE: Selection of composite resin impacts its response to preheating and the resulting viscosity, film thickness, and magnitude of ceramic strengthening.


Subject(s)
Ceramics , Composite Resins , Aluminum Silicates , Dental Porcelain , Materials Testing , Potassium Compounds , Resin Cements , Surface Properties
15.
Braz Oral Res ; 32: e49, 2018 Jun 07.
Article in English | MEDLINE | ID: mdl-29898019

ABSTRACT

The influence of inorganic filler content of resin-based luting agents (RBLAs) on color change (ΔE00), CIEL*a*b* (individual color coordinates), and translucency parameters (TP) of simulated ceramic laminate veneer (CLV) was investigated. RBLAs with low, intermediate, and high inorganic filler content (55%, 65%, and 75% mass fractions, respectively) were prepared. Feldspar ceramic (Vitablocs Mark II) specimens (1.2 mm × 0.8 mm, A1C shade) were bonded to simulated composite resin substrates (1.6 mm × 1.2 mm, A2D shade) using three experimental and a commercial (RelyX Veneer) RBLA (translucent shade). The ΔE00 was calculated by CIEDE2000 color difference metric under three conditions (before, immediately after, and 24 h after luting). The TP was calculated using CIEL*a*b* color coordinates measured over white and black backgrounds. Surface morphology of the RBLAs was analyzed. One-way and two-way analyses of variance with a post-hoc Tukey's test were used respectively to calculate TP, CIEL*a*b* coordinates, and ΔE00 (α= 0.05). Overall, the tested RBLAs presented clinically visible ∆E00 values under the three conditions evaluated. For all RBLAs, higher ∆E00 values were observed between measurements obtained before and immediately after luting. Different inorganic filler content did not significantly increase the opacity of the ceramic-luting agents-resin composite set. The variation in inorganic filler content did not influence significantly the TP of simulated CLV; although all of the experimental RBLAs tested yielded ∆E00 above the perceptibility threshold. The L*, a*, and b* individual color coordinates were cementation-dependent.


Subject(s)
Ceramics/chemistry , Dental Veneers , Prosthesis Coloring/methods , Resin Cements/chemistry , Color , Colorimetry , Materials Testing , Microscopy, Electron, Scanning , Reference Values , Reproducibility of Results , Statistics, Nonparametric , Surface Properties , Time Factors
16.
Braz Dent J ; 29(2): 202-207, 2018.
Article in English | MEDLINE | ID: mdl-29898069

ABSTRACT

This study evaluated the effect of the accelerated artificial aging (AAA) on feldspar ceramic strength and the reinforcing effect promoted by adhesive cementation with resin luting agent. One hundred twenty feldspar ceramic disks were obtained. Sixty disks were acid-etched, silanized, and coated with an experimental resin luting agent simulating the adhesive luting procedures. Four groups were created (n=30): uncoated ceramic (control group), uncoated ceramic submitted to AAA, ceramic coated with resin luting agent, and coated ceramic submitted to AAA. Biaxial flexural testing with ball-on-ring setup was carried out. Biaxial flexural strength (s bf , MPa), characteristic strength (s 0 , MPa), and Weibull modulus (m) were calculated for axial positions z=0 (ceramic surface) and z=-t2 (luting agent surface). Data of s bf at positions z=0 and z=-t2 were separately submitted to statistical analyses (a=0.05). The uncoated ceramic submitted to AAA had no significant difference in s bf and s 0 compared with the control group. Resin coating of the ceramic increased s bf and s 0 at z=0. The AAA increased the s bf and s 0 for the resin-coated ceramic specimens at z=0 and also the s 0 at axial position z=-t2. The structural reliability at z=0 and z=-t2 was not influenced by the variables tested. In conclusion, resin coating improved the mechanical strength of the feldspar ceramic. The AAA procedure was not effective in aging the uncoated or resin-coated feldspar ceramic specimens.


Subject(s)
Aluminum Silicates/chemistry , Dental Cements/chemistry , Dental Porcelain/chemistry , Materials Testing , Potassium Compounds/chemistry , Resin Cements/chemistry , Composite Resins/chemistry , Dental Bonding , Dental Stress Analysis
17.
RFO UPF ; 22(2): 243-247, 08/01/2018.
Article in Portuguese | LILACS | ID: biblio-877844

ABSTRACT

Introdução: a doença periodontal representa um fator de risco para o câncer bucal, uma vez que resulta no aumento na produção de espécies oxigênio-reativas, devido ao processo inflamatório em nível local e sistêmico. Essas substâncias interferem na estabilidade celular, podendo resultar no aumento da frequência de micronúcleos, que podem atuar como marcadores biológicos. Objetivo: buscar evidências científicas que demonstrem a relação entre a doença periodontal e a frequência elevada de micronúcleos. Métodos: a pesquisa foi realizada por meio de uma revisão sistemática da literatura em bases de dados científicas, utilizando os seguintes descritores: a) na Bireme: doença periodontal e micronúcleos; doença periodontal e análise citogenética; b) na PubMed: periodontal disease and micronuclei; periodontal disease and cytogenetic analysis. Resultados: a busca nas bases de dados totalizou 96 artigos. Desses, foram encontrados 3 na Bireme e 93 na PubMed. Dos 96 artigos encontrados, somente 4 responderam a questão norteadora. Desses, somente dois estudaram a relação entre a doença periodontal e outros fatores com a produção de micronúcleos. Os outros dois estudaram essa relação de forma isolada. Apenas em um artigo não foi observada significância estatística para a relação entre a frequência elevada de micronúcleos em sujeitos com a doença periodontal, quando comparados com sujeitos sem a doença. Em três dos quatro trabalhos, foi observada significância estatística entre esses fatores. Conclusão: sendo assim, destaca-se a importância em desenvolver estudos posteriores visando fortalecer essas evidências científicas, para que, futuramente, a análise de micronúcleos possa ser utilizada como um critério de controle prévio da carcinogênese.

18.
Braz. oral res. (Online) ; 32: e49, 2018. tab, graf
Article in English | LILACS | ID: biblio-952140

ABSTRACT

Abstract The influence of inorganic filler content of resin-based luting agents (RBLAs) on color change (ΔE00), CIEL*a*b* (individual color coordinates), and translucency parameters (TP) of simulated ceramic laminate veneer (CLV) was investigated. RBLAs with low, intermediate, and high inorganic filler content (55%, 65%, and 75% mass fractions, respectively) were prepared. Feldspar ceramic (Vitablocs Mark II) specimens (1.2 mm × 0.8 mm, A1C shade) were bonded to simulated composite resin substrates (1.6 mm × 1.2 mm, A2D shade) using three experimental and a commercial (RelyX Veneer) RBLA (translucent shade). The ΔE00 was calculated by CIEDE2000 color difference metric under three conditions (before, immediately after, and 24 h after luting). The TP was calculated using CIEL*a*b* color coordinates measured over white and black backgrounds. Surface morphology of the RBLAs was analyzed. One-way and two-way analyses of variance with a post-hoc Tukey's test were used respectively to calculate TP, CIEL*a*b* coordinates, and ΔE00 (α= 0.05). Overall, the tested RBLAs presented clinically visible ∆E00 values under the three conditions evaluated. For all RBLAs, higher ∆E00 values were observed between measurements obtained before and immediately after luting. Different inorganic filler content did not significantly increase the opacity of the ceramic-luting agents-resin composite set. The variation in inorganic filler content did not influence significantly the TP of simulated CLV; although all of the experimental RBLAs tested yielded ∆E00 above the perceptibility threshold. The L*, a*, and b* individual color coordinates were cementation-dependent.


Subject(s)
Prosthesis Coloring/methods , Resin Cements/chemistry , Dental Veneers , Reference Values , Surface Properties , Time Factors , Materials Testing , Microscopy, Electron, Scanning , Ceramics/chemistry , Reproducibility of Results , Color , Colorimetry , Statistics, Nonparametric
19.
Full dent. sci ; 9(36): 111-116, 2018. graf, tab
Article in Portuguese | BBO - Dentistry | ID: biblio-994775

ABSTRACT

A constante busca pelo sorriso étnico cultural harmônico está fazendo com que, cada vez mais, as pessoas procurem o tratamento odontológico. Assim, o presente estudo teve como objetivo avaliar a percepção de estética dental de odontólogos que estavam cursando diferentes especialidades, levando em consideração o quanto isso afeta na sua conduta clínica. A coleta de dados foi realizada por meio de um questionário, composta por 108 cirurgiões dentistas cursando diferentes áreas de especialização em uma escola de pós-graduação no ano de 2016, em que cada participante avaliou fotografias que possuíam cinco alterações frequentes na dentição anterior. Foi realizada a análise descritiva dos dados e o teste qui-quadrado para a análise quantitativa. Através dos resultados, verificou-se que fatores como idade, especialização prévia e tipo de especialização em andamento apresentaram relação estatisticamente significante na percepção estética entre as diferentes áreas de atuação da Odontologia. Desse modo, foi possível concluir que o sorriso considerado esteticamente mais agradável entre os entrevistados possuía as seguintes características: plano incisal intermediário entre o reto e o que segue a linha do sorriso, nível gengival harmônico, ausência de desvio de linha média, ausência de diastema e matiz A1 (AU).


The constant search for a harmonious cultural ethnic smile is causing more people to seek dental treatment. Thus, the present study aimed to evaluate the perception of dental aesthetics by dentists who were studying different specialties, taking into consideration how much this affects their clinical behavior. Data collection was performed through a questionnaire of 108 dentists attending different areas of specialization at a postgraduate school in 2016, in which each participant evaluated photographs that had five frequent changes in the previous dentition. Descriptive data analysis and chi-square test were performed for quantitative analysis. The results showed that factors such as age, previous specialization and type of specialization in progress had a statistically significant relationship in the aesthetic perception in different areas of Dentistry practice. So it was possible to conclude that the smile considered aesthetically more pleasant for the interviewers had the following characteristics: intermediate incisal plane between the straight and the smile line, gingival harmonic level, absence of midline deviation, absence of diastema, and A1 shade (AU).


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Perception , Smiling , Dentists , Esthetics, Dental , Brazil , Chi-Square Distribution , Cross-Sectional Studies/methods , Surveys and Questionnaires
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