Clinical performance and patient-related outcome measures of digitally fabricated complete dentures: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: The demand to streamline workflow while increasing patient comfort and satisfaction in the manufacturing of removable complete dentures (CDs) is growing, and computer-aided design and computer-aided manufacturing (CAD-CAM) technology has gained prominence. However, a systematic review and meta-analysis of the clinical performance and patient-related outcome measures (PROMs) of digitally fabricated complete dentures is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to determine whether digitally fabricated CDs improve the clinical performance and PROMs compared with conventionally fabricated CDs. MATERIAL AND METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was registered at the International Prospective Register of Systematic Reviews (CRD42023433909). This review aimed to address the question "Do digitally fabricated CDs improve clinical performance and PROMs compared with conventional CDs?" Two independent authors conducted electronic searches up to September 2023. Denture base retention and patient satisfaction were analyzed through the continuous outcome evaluated by mean difference and standard deviation, with 95% confidence intervals. The risk of bias in each study was assessed using the Risk of Bias In Non-randomized Studies of Interventions and the Risk of Bias based on the Cochrane risk of bias tool for randomized trials. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation. RESULTS: A total of 1505 articles were found during the search, and 16 were included in this review. The main outcomes were grouped into clinical performance (retention, adaptation or fit, clinician's denture quality assessment, masticatory efficiency, and occlusal force) and PROMs (patient satisfaction, oral health related quality of life, final choice, and willingness-to-pay). In terms of denture base retention, between conventional CDs and printed CDs analyzes, conventional CDs exhibited better retention (P=.02), but no significant difference was found between the conventional CDs and milled CDs (P=.20). In terms of patient satisfaction, no statistically significant difference was found between the manufacturing methods of digitally fabricated CDs (printed CD, P=.55; milled CD, P=.08). CONCLUSIONS: Digitally fabricated CDs showed similar or better clinical performance than conventional CDs, and different types of digital manufacturing processes for complete dentures did not influence PROMs.

Does the use of conventional complete dentures influence taste perception? A systematic review.

STATEMENT OF PROBLEM: Although conventional complete dentures are widely used, a systematic review of their influence on wearers' taste perception is lacking. PURPOSE: The purpose of this systematic review was to determine whether conventional complete dentures influence the taste perception of edentulous patients. MATERIAL AND METHODS: This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42022341567), and the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were followed. The guiding question was: "Does the use of complete dentures influence the taste perception of edentulous patients?" Two reviewers searched articles in the PubMed/MEDLINE, Scopus, Cochrane Library, and https://clinicaltrials.gov databases up to June 2022. The risk of bias in each study was assessed using the risk of bias in nonrandomized studies of interventions and the risk of bias based on the Cochrane risk of bias tool for randomized trials. The certainty of evidence was assessed using grading of recommendations, assessment, development, and evaluation (GRADE). RESULTS: A total of 883 articles were found with the search, and 7 were included in this review. Various changes in taste perception were identified in some of these studies. CONCLUSIONS: The use of conventional complete dentures can influence the perception of the 4 primary tastes (sweet, salty, sour, and bitter) of edentulous patients, which may negatively interfere with the perception of flavor.

Photodynamic therapy in the treatment of denture stomatitis: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Photodynamic therapy is widely used in dentistry, but limited evidence exists regarding its effectiveness in treating denture stomatitis. High resistance to antifungals has been reported, and photodynamic therapy could be an alternative treatment. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate whether photodynamic therapy is effective in reducing denture stomatitis. MATERIAL AND METHODS: A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and recorded in the prospective register of systematic reviews (PROSPERO) (CRD42020205589) to answer the population, intervention, control, outcome (PICO) question: "Is photodynamic therapy effective in the treatment of denture stomatitis when compared with the use of antifungal agents?" Electronic searches were performed in databases PubMed/MEDLINE, Cochrane library, and Web of Science for articles published until February 2021 by using the following terms: (denture stomatitis OR oral candidiasis) AND (low-level light therapy OR laser therapy OR lasers OR photodynamic therapies OR photochemotherapy) AND (antifungal drugs OR antifungal agents OR antimicrobial OR treatment). Clinical trials and randomized clinical trials, studies in the English language, and studies comparing antifungal agents with photodynamic therapy were included. RESULTS: In total, 5 articles were selected for the qualitative analysis and 3 for the meta-analysis. No significant difference was detected between antifungal therapy and photodynamic therapy in the reduction of colony-forming units on the palate. In a subgroup analysis, a significant difference was found in the reduction of colony-forming units on the palate at 15 days and at the denture surface at 30 days. CONCLUSIONS: Photodynamic therapy is effective in the treatment of denture stomatitis, but after 30 days and 15 days, the antifungals demonstrated better performance.

Effect of Adhesive Resin Application on the Durability of Adhesion to CAD/CAM Glass-Ceramics after either Hydrofluoric Acid Etching or Self-etch Primer Application.

PURPOSE: To evaluate the effect of two surface conditioning methods, namely conventional hydrofluoric acid vs self-etching primer, and the application of adhesive on the bond strength of resin cement to CAD/CAM glass-ceramics. MATERIALS AND METHODS: Blocks (N = 96) (12 x 10 x 2.5 mm) were manufactured, 24 for each tested ceramic type: lithium silicate ceramic (LS), polymer-infiltrated ceramic (PIC), leucite-reinforced feldspathic ceramic (FD), and lithium-disilicate glass-ceramic (LD). For bond strength testing, 64 blocks were randomly divided into 16 groups (4 blocks per group) according to the following factors: ceramic: 4 levels; etching: 2 levels (HFS: hydrofluoric acid + silane or Monobond Etch & Prime [MEP]); and adhesive application: 2 levels, with (signified as A) and without. Then for each group, 15 resin cement cylinders (AllCem Dual, FGM) were built up. All specimens were subjected to thermocycling (10,000 cycles) and to shear bonding strength testing (SBS) (100 kgf, 0.5 mm/min). Mean shear stresses (MPa) were statistically analyzed by three-way ANOVA, Tukey's test, and Weibull analysis. RESULTS: The mean bond strength of group PIC-HFS-A (28.45 ± 7.6 MPa) was significantly higher than that of groups LS-HFS-A (12.11 ± 2.7MPa) and FDHFSA (20.86 ± 2.0MPa). Group PIC-HFS bond strength (25.02 ± 6.5 MPa) was significantly higher only when compared to group LS-HFS (15.82 ± 4.4 MPa). The LS group presented lower SBS compared to all other groups. No significant differences were found between HFS and MEP surface treatments. CONCLUSION: Surface treatment with MEP promotes adhesion similar to that of HFS. Additional application of adhesive after the surface treatments did not improve the bond strength.

Biaxial flexure strength and physicochemical characterization of a CAD/CAM lithium disilicate ceramic: effect of etching time, silane, and adhesive applications.

OBJECTIVE: To evaluate the effect of different acid etching time and bonding agent (silane and/or adhesive system) on biaxial flexural strength and physico-chemical properties of a lithium disilicate ceramic. MATERIAL AND METHODS: One hundred twenty ceramic discs were made and divided into 8 groups (n = 15) according to factors "etching time" (20 and 120 s) with hydrofluoric acid (HF) and "bonding agent" (C, no bonding agent; S, silane, A, adhesive; and SA, silane + adhesive). After surface treatment, a resin cement layer was applied to the surface and all specimens were subjected to biaxial flexural strength (BFS) test with treated surfaces loaded in tension (1 mm/min). The Weibull analyses and complementary analyses were also performed. Statistical analysis was done with 2-way ANOVA and the Tukey test (α = 0.05). RESULTS: ANOVA revealed that the factors "etching time" (p = 0.0003) and "bonding agent" (p = 0.007) were statistically significant. In the overall analysis, the HF120S group (272.02 ± 35.30A MPa) presented significantly higher BFS than that of HF120C (218.45 ± 17.15CD MPa) and HF20S (228.40 ± 37.83BCDMPa). On the other hand, the HF20A group (208.92 ± 31.16D MPa) had significantly lower BFS than HF120S (272.02 ± 35.30A), HF120A (254.42 ± 26.87ABC) and HF120SA (259.30 ± 36.55AB) groups (Tukey). The Weibull modulus (m) of all groups was significantly different from each other (p = 0.000). CONCLUSIONS: Regardless of etching time, the application of silane alone is sufficient to increase the flexural strength of glass ceramic, eliminating the need for the application of adhesive systems. Moreover, if only silane or adhesive is applied, 120-s HF application should increase the flexural resistance of the lithium disilicate ceramic. CLINICAL SIGNIFICANCE: Applications of adhesive systems after silanization can be suppressed from the surface treatment protocol of glass ceramics, since it does not improve their mechanical strength.

The influence of nocturnal use of complete dentures on cardiorespiratory parameters of patients with obstructive sleep apnea: a systematic review and meta-analysis.

OBJECTIVE: To assess whether wearing complete dentures during sleep influences the cardiorespiratory parameters of patients with obstructive sleep apnea (OSA). MATERIALS AND METHODS: A systematic review was performed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to determine whether wearing complete dentures during sleep influences the cardiorespiratory parameters of patients with OSA. An electronic search was performed in four databases, PubMed/MEDLINE, Cochrane Library, Web of Science, and SCOPUS, and in the gray literature (TRIALS) until November 2021. This review included clinical trials, randomized clinical trials, and studies in which patients using conventional complete dentures were diagnosed with OSA using polysomnography and the cardiorespiratory parameters were measured using oximetry or polysomnography during sleep. RESULTS: In total, 788 references were found in the database, and 12 articles were selected for full reading. Six articles were selected for qualitative and quantitative analyses after applying the inclusion and exclusion criteria and reading the full article. The meta-analysis showed that mean oxygen saturation (SpO2) increased with the use of complete dentures (p = 0.001), but the other parameters showed no significant differences between those wearing and not wearing dentures during sleep. CONCLUSIONS: The mean SpO2 reduced in patients wearing complete dentures, but the other cardiorespiratory parameters evaluated were not affected. CLINICAL RELEVANCE: This study indicates a possible influence of the use of complete dentures on the mean SpO2 during sleep. The use of complete denture could aid other treatments in improving respiratory and sleep quality.

Which Zirconia Surface-cleaning Strategy Improves Adhesion of Resin Composite Cement after Saliva Contamination? A Systematic Review and Meta-Analysis.

PURPOSE: To identify the most effective cleaning method for saliva-contaminated zirconia surface before adhesive cementation through a systematic review and meta-analysis. MATERIALS AND METHODS: PubMed, Scopus, and Web of Science databases were searched to select in vitro studies published through October 2021. Studies that did not perform aging methods, had a sample size less than 5 per group, or did not present a group with zirconia contaminated only with saliva were excluded. Data were extracted and risk of bias was assessed. Statistical analysis comparing the cleaning methods was conducted, and the standardized mean difference was assessed using the R software program. RESULTS: Among 804 potentially eligible studies, 36 were selected for full-text reading, of which 13 were included in qualitative analysis, and 11 of these were subsequently included in the quantitative analysis. A meta-analysis revealed a significant difference in the bond strength between the cleaning methods. Sandblasting with Al2O3  showed a higher bond strength than cleaning solution (Ivoclean, Ivoclar Vivadent) (p < 0.01, I2 = 65%), and both methods promoted higher resin-bond strength to zirconia than water cleaning. In addition, there was no significant difference in the bond strength between alcohol (p = 0.35, I2 = 79%), phosphoric acid (p < 0.23, I2 = 90%), and water cleaning. CONCLUSION: Sandblasting with Al2O3 seems to be the best method for zirconia surface cleaning before adhesive luting, promoting better resin-bond strength to zirconia.

Effect of finishing/polishing techniques and aging on topography, C. albicans adherence, and flexural strength of ultra-translucent zirconia: an in situ study.

OBJECTIVE: To investigate the influence of different finishing/polishing techniques and in situ aging on the flexural strength (σ), surface roughness, and Candida albicans adherence of 5 mol% yttria-stabilized zirconia (ultratranslucent zirconia). MATERIALS AND METHODS: A total of 120 zirconia bars (Prettau Anterior, Zirkonzahn) with dimensions of 8 × 2 × 0.5 mm were divided into 8 groups (n = 15) according to two factors: "in situ aging" (non-aged and aged (A)) and "finishing/polishing" (control (C), diamond rubber polishing (R), coarse grit diamond bur abrasion (B), and coarse grit diamond bur abrasion + diamond rubber polishing (BR)). Half of the samples from each group were subjected to a 60-day in situ aging by fixing the bars into cavities prepared in the posterior region of the base of complete or partial dentures of 15 patients. The samples were then subjected to the mini flexural (σ) test (1 mm/min). A total of 40 zirconia blocks (5 × 5 × 2 mm) were prepared and subjected to roughness (Ra) analyses and fungal adherence and complementary analyses (X-ray diffraction (XRD) and scanning electron microscopy (SEM)). The data of mean σ (MPa) and roughness Ra (µm) were statistically analyzed by two-way and one-way ANOVA, respectively, and Tukey's test. The Weibull analysis was performed for σ data. The fungal adhesion (Log CFU/mL) data were analyzed by Kruskal-Wallis tests. RESULTS: For flexural resistance, the "finishing/polishing" factor was statistically significant (P = 0.0001); however, the "in situ aging" factor (P = 0.4458) was not significant. The non-aged (507.3 ± 115.7 MPa) and aged (487.6 ± 118.4 MPa) rubber polishing groups exhibited higher mean σ than the other techniques. The non-aged (260.2 ± 43.3 MPa) and aged (270.1 ± 48.8 MPa) bur abrasion groups presented lower σ. The coarse-grit diamond bur abrasion group (1.82 ± 0.61 µm) presented the highest roughness value (P = 0.001). Cell adhesion was not different among groups (P = 0.053). Group B presented the most irregular surface and the highest roughness Ra of 0.61 m. CONCLUSIONS: The finishing of ultratranslucent zirconia might be preferably done with a diamond rubber polisher. Moreover, the protocols used did not interfere with Candida albicans adhesion. CLINICAL RELEVANCE: Coarse-grit diamond burs might be avoided for finishing ultratranslucent monolithic zirconia, which might be preferably performed with a diamond rubber polisher.

Are exercises with or without occlusal splints more effective in the reduction of pain in patients with temporomandibular disorders of myogenic origin? A systematic review

Abstract Temporomandibular disorders (TMD) is a term used to describe a set of clinical conditions that may compromise the temporomandibular joint (TMJ) and masticatory muscles and/or associated structures, considered the most frequent cause of orofacial pain of non-dental origin. In recent years, many forms of physical therapy have been used in the treatment of TMD to reduce pain and improve the range of mandibular movement present in this impairment. Among these resources are kinesiotherapy (exercise), electrothermal and manual therapy, acupuncture, training posture, mobilizations, and biofeedback. Objectives To determine if exercises with or without occlusal splints are effective in reducing pain in patients with temporomandibular disorders (TMD) of myogenic origin. Methodology This systematic review was registered in the International Prospective Register of Systematic Reviews (CRD 42019134244). Controlled trials published in PubMed, Scopus, and Cochrane Library following PRISMA guidelines up to April 2022 were randomized and included. The population above 18 years, which evaluated the effectiveness of exercise with or without occlusal splints in reducing pain in patients with TMD of myogenic origin, diagnosed through the Research Diagnostic Criteria for Temporomandibular Disorders, was also included. There was no restriction on the period of publication. Cochrane risk of bias analysis was performed. Results Of the five included articles, all showed a reduction of pain, but without significant differences between the interventions performed. Additionally, studies that evaluated the quality of life and mandibular movements showed a reduction in pain, but no significant differences between therapies. Conclusion The analyzed studies showed no difference in the improvement of pain, quality of life, and mandibular movements between the groups that performed only exercises or the associated treatments.

Dispositivos intraorais no tratamento da apneia obstrutiva do sono em pacientes desdentados: uma revisão sistematizada de literatura / Intraoral devices in the treatment of obstructive sleep apnea in edentulous patients: a systematized literature review

Objetivo: elucidar aspectos envolvidos no uso dos dispositivos intraorais para apneia obstrutiva do sono em indivíduos desdentados totais, como a eficácia dos dispositivos, o conforto e retenção/estabilidade. Metodologia: essa revisão seguiu o checklist do PRISMA, no qual foram incluídos estudos clínicos em inglês, sem restrição de tempo, em que foram utilizados dispositivos para apneia obstrutiva do sono em pacientes desdentados bimaxilares. As buscas foram realizadas nas bases de dados PubMed / MEDLINE, Cochrane e SCOPUS até março de 2021. Resultados: Após as diferentes etapas do processo de seleção dos artigos, foram selecionados 6 estudos para esta revisão, sendo 5 relatos de caso e 1 ensaio clínico. Os estudos relataram uma redução no índice apneia-hipopneia. Em três estudos houve redução expressiva, proporcionando a redução no grau de apneia, de severa para moderada e moderada para leve. A protrusão alcançada com os dispositivos foi adequada para o efeito desejado, em todos os dispositivos. Os estudos não reportam deslocamento do dispositivo e apenas um relata desconforto temporário. Conclusão: Os dispositivos intraorais foram eficazes no tratamento da apneia obstrutiva do sono em pacientes desdentados e os usuários não tiveram queixas quanto ao conforto e estáveis... (AU)

Objective: to elucidate aspects involved in the use of intraoral devices for obstructive sleep apnea in complete edentulous patients, such as the effectiveness of these devices, comfort and retention/stability. Methodology: this review followed the PRISMA checklist, included clinical studies in English, without publication restrictions, in which intraoral devices were used for obstructive sleep apnea in edentulous bimaxillary patients. The search was carried out in PubMed/MEDLINE, Cochrane and SCOPUS databases, until March 2021. Results: After the different stages of the article selection process, 6 studies were selected for this review, 5 case reports and 1 clinical trial. The studies reported a reduction in the apnea-hypopnea index. In three studies there was a significant reduction in the degree of apnea, from severe to moderate and moderate to mild. The protrusion achieved with the devices was adequate for the desired effect, in all devices. Studies did not report displacement of the device and only one reports temporary discomfort. Conclusion: Intraoral devices were effective in treating obstructive sleep apnea in edentulous patients and users had no complaints about comfort and stability... (AU)

Does nocturnal use of a complete denture interfere with the degree of obstructive sleep apnea? A systematic review and meta-analysis.

BACKGROUND: The impact of a complete denture on obstructive sleep apnea is not well understood. Therefore, this study aimed to evaluate the relationship between nighttime use of complete dentures and obstructive sleep apnea and determine if wearing a complete denture during sleep changes the degree of obstructive sleep apnea. METHODS: This systematic review followed the notification items for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was recorded in the International Prospective Registry of Systematic Reviews (PROSPERO) under number CRD42020183167. An electronic search in the PubMed/MEDLINE, Scopus, and Cochrane Library databases for articles published until September 2020 was conducted. The search strategy used the terms (complete denture OR denture OR edentulous OR edentulism) AND (quality of sleep OR sleep OR apnea OR obstructive sleep apnea). Only prospective, retrospective, controlled, and randomized clinical studies of patients wearing complete dentures, studies comparing sleep with and without the prosthesis, and studies in which patients were diagnosed with obstructive sleep apnea by polysomnography were included in the review. RESULTS: In total, four articles were selected for the qualitative and quantitative analyses. A total of 144 patients, with an average age of 60 years, were studied. The meta-analysis showed that there was no statistical difference in the apnea-hypopnea index between using and not using the prosthesis during sleep. CONCLUSIONS: The use of complete dentures during sleep does not influence the degree of obstructive sleep apnea.

Effect of finishing/polishing techniques and low temperature degradation on the surface topography, phase transformation and flexural strength of ultra-translucent ZrO2 ceramic.

OBJECTIVE: To investigate the effect of different surface finishing and polishing regimes and low temperature degradation on flexural strength, phase transformation and surface topography of ultra-translucent ZrO2 ceramic. METHODS: 300 (n=15/group) of conventional zirconia (Z: Ice Zirkon Transluzent) and ultra-translucent zirconia (UT: Prettau Anterior) bar-specimens were made and divided according to the "Finishing/Polishing" - (C - Control, B - diamond rubber polishers, P - adjusting with burs, PB - adjusting with burs+diamond polishers, PG - adjusting with burs+glaze), "Low temperature Degradation (LTD)" (with or without a treatment at 127°C, 1.7bar/24h). Then, a 3-point mini flexural test was performed in a universal testing machine (1mm/min, 500kgf load cell). SEM, EDS, XDR, AFM, optical profilometry and Weibull analysis were performed. Data were analyzed by 3-way ANOVA and Tukey's post-test (5%). RESULTS: Groups ZPBD (1670±253MPa), ZBD (1664±217MPa), and ZB (1655±3678MPa) showed significantly higher flexural strength than the UTPG group (372±56MPa). The Weibull modulus was significantly higher for the ZPD group compared to the UB, UCD, UPD and UPBD, while UTB, UTCD and UTPD had the lowest value. Monoclinic phases were observed only in the conventional zirconia groups and were more evident after LTD. Diamond rubber polishers presented less roughness for both zirconias. SIGNIFICANCE: The use of diamond rubber polishers is the most suitable finishing/polishing method for zirconia ceramic restorations and that final glazing reduces the fracture resistance of these materials.

Lentes de contato em zircônia monolítica ultratranslúcida: realidade ou futuro? Relato de caso com um ano de acompanhamento clínico / Ultratranslucent monolithic zirconia ultrathin veneers: case report with 1-year follow-up

O objetivo deste estudo foi apresentar um relato de caso clínico de dez lentes de contato em zircônia ultratranslúcida após acompanhamento de um ano, descrevendo as etapas clínicas e discutindo os aspectos relevantes desse tipo de opção restauradora. Os procedimentos para a confecção das lentes de zircônia (Prettau Anterior, Zirkonzahn) seguiram as etapas de planejamento digital do sorriso, enceramento diagnóstico, mock-up, cirurgia gengival, preparos minimamente invasivos dos elementos 15 ao 25 e cimentação adesiva. Após a finalização do tratamento, observou-se um excelente resultado estético e funcional, o qual se manteve após um ano de acompanhamento. Assim, laminados cerâmicos de zircônia ultratranslúcida podem oferecer uma elevada estética e apresentar longevidade, entretanto estudos longitudinais e um acompanhamento em longo prazo são necessários para determinar a durabilidade clínica deste tipo de procedimento. (AU)

The aim of this study was to present a clinical case report often ultratranslucent zirconia veneers after one year of follow-up, describe the clinical stages and discussing the relevant aspects of this type of restorative option. The procedures for zirconia veneers (Prettau Anterior, Zirkonzahn) followed the steps of digital smile planning, diagnostic wax-up, mock-up, gingival surgery, minimally invasive preparations of elements 15 to 25 and adhesive cementation. After the treatment was finished an excellent esthetic and functional result was observed, which was maintained after one year of follow-up. Thus, ultratranslucent zirconia ceramic veneers can offer high esthetics and longevity, however, longitudinal studies and long-term follow-up are necessary to determine the clinical durability of this type of procedure. (AU)

Efeito de diferentes regimes de acabamento e polimento na resistência à flexão e topografia superficial de zircônias monolíticas / Effect of different finishing and polishing regimes on flexural strength and surface topography of monolithic zirconia

Introdução: As restaurações em zircônia monolítica podem exigir ajustes em sua estrutura antes da cimentação. Diversos métodos de acabamento e polimento são sugeridos na literatura, entretanto estes podem promover mudanças estruturais e na superfície da zircônia, o que pode afetar a resistência mecânica do material em longo prazo. Objetivo: Investigar in vitro o efeito de diferentes regimes de acabamento e polimento e da degradação em baixas temperaturas na resistência à flexão e topografia superficial em dois tipos de zircônia monolíticas. Metodologia: 300 barras de zircônia (Z: ice zirkon transluzent/Convencional e UT: Prettau Anterior/Ultratranslúcida, zirkonzahn, Gais, Itália) foram confeccionadas nas dimensões 2,1- 1,3x 2,5x10mm, lixadas e sinterizadas, apresentando dimensões finais de 1,7-1 x 2 x 8mm, divididas em 20 grupos (n=15) de acordo com três fatores: "Zircônia"-2 níveis (Z: Convencional; UT: Ultratranslúcida), "Acabamento e Polimento"- 5 níveis (C- Controle; BBorrachas; P- Asperização com pontas; PB- Asperização com pontas + Borrachas; PGAsperização com pontas + glaze) e "Degradação"- 2 níveis (COMD: autoclave à 127°C, 1,7 bar /24h; sem degradação). Foi realizado o ensaio de resistência à miniflexão (3 pontos), com v:1mm/min e células de carga 500N e 5000N. Duas amostras de cada grupo foram preparadas para microscopia eletrônica de varredura (MEV)/ Espectrometria por Energia Dispersiva de Raios-X (EDS) e microscopia de força atômica (MFA). A rugosidade média de cada grupo foi avaliada qualitativamente. Os dados foram analisados por ANOVA (3 fatores) e Tukey (5%). Resultados: Os fatores "Zircônia" (p=0,0000), "Acabamento e Polimento" (p=0,0000) e "Degradação" (p=0,01) e foram estatisticamente significantes, sendo as maiores médias encontradas nos grupos ZPBD (1670.2 ± 252.73)A , ZBD (1663.5 ± 216.80)A e ZB (1654.7 ± 367.79A ) e as menores na zircônia UT, destacando-se o grupo UTPG (372.1±56.295)G . No MEV pode-se observar que a camada de glaze não recobriu toda superfície da zircônia e as borrachas promoveram uma superfície mais uniforme. O EDS revelou maior quantidade de óxido de ítrio nas zircônias UT, já na MFA maior valor de Ra foi encontrado nos grupos asperizados, sendo UT>Z. Conclusão: O protocolo mais indicado para acabamento e polimento das restaurações em zircônia são o uso de borrachas diamantadas. A asperização seguida pelo glaze reduziu a resistência da zircônia e o uso das borrachas forneceram uma superfície mais uniforme em relação aos demais métodos (AU).

Background: The restorations in monolithic zirconia may require adjustments in their structure prior to cementation. Several methods of finishing and polishing are suggested in the literature, however they can promote structural and surface changes of the zirconia, which can affect the mechanical strength of the material in the long term. Aim: To investigate in vitro the effect of different finishing and polishing regimes and low temperature degradation on flexural strength and surface topography in two types of monolithic zirconia. Method: 300 zirconia bars (Z: ice zirkon transluzent / Conventional and UT: Prettau Anterior / Ultratransluzent, zirkonzahn, Gais, Italy) were made in sizes 2.1-1.3x 2.5x10mm, sanded and sintered, (Z: Conventional; UT: Ultratransluzent), "Finishing and Polishing" - 5 levels (C- Control, B- diamond polishers, Pgrinding with burs, PB- grinding with burs + diamond polishers, PG- grinding with burs + glaze) and "Degradation" - 2 levels (WithD: autoclave at 127 ° C, 1,7 bar / 24h, without degradation). The miniflexion resistance test (3 points) was performed, with v: 1mm / min and 500N and 5000N load cells. Two samples from each group were prepared for Scanning Electron Microscopy (SEM) / X-ray Dispersive Energy Spectrometry (EDS) and Atomic Force Microscopy (AFM). The mean roughness of each group was evaluated qualitatively. Data were analyzed by ANOVA (3 factors) and Tukey (5%). Results: The "Zirconia" (p = 0.0000), "Finishing and Polishing" (p = 0.0000) and "Degradation" factors (p = 0.01) were statistically significant, ZBD (1670.2 ± 252.73)A , ZBD (1663.5 ± 216.80)A and ZB (1654.7 ± 367.79A ) and the lowest in the UT zirconia, standing out the UTPG group (372.1 ± 56.295)G . In the SEM it can be observed that the glaze layer did not cover the whole surface of the zirconia and the diamond polishers promoted a more uniform surface. The EDS showed higher amount of yttrium oxide in the UT zirconia and the AFM showed the higher Ra value was found in the roughened groups, with UT> Z. Conclusion: The most suitable protocol for finishing and polishing restorations in zirconia is the use of diamond polishers. The grinding followed by glaze reduced zirconia resistance and the use of the diamond polishers provided a more uniform surface compared to the other methods (AU).