Effect of surface roughness and biofilm formation on the color properties of resin-infiltrated ceramic and lithium disilicate glass-ceramic CAD-CAM materials.

STATEMENT OF PROBLEM: Computer-aided design and computer-aided manufacturing (CAD-CAM) materials have become popular for dental restorations; however, which materials should be preferred in terms of surface properties after biofilm formation is unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of biofilm formation on the discoloration properties of resin-infiltrated ceramic and glass-ceramic CAD-CAM materials and human teeth and to examine the effect of the brushing procedure on color change. MATERIAL AND METHODS: One hundred and six 2-mm-thick specimens were prepared from IPS e.max CAD and Cerasmart, and a total of 53 intact human teeth were used. Five specimens from each group were used to measure the amount of live biomass in the biofilm. The remaining 48 specimens in each group were divided into 4 subgroups: kept in distilled water without the formation of dental biofilm (DW), kept in tea without the formation of dental biofilm (T), kept in distilled water after the formation of dental biofilm (DWB), and kept in tea after the formation of dental biofilm (TB) (n=12). After finishing and polishing the materials, initial color measurements were made using a spectrophotometer, and surface roughness measurements were made using noncontact profilometer. After creating a biofilm layer in DWB and TB, all specimens were kept in their solutions at 37 °C for 24 hours, and the color measurements were repeated. After the biofilm layer had been removed by brushing, a third color measurement was made. The data were statistically analyzed with one-way analysis of variance (ANOVA) and two-way ANOVA (α=.05). RESULTS: The lowest roughness value was observed in Cerasmart. Tooth-IPS e.max CAD gave similar results. The Cerasmart material had the most viable biomass, whereas the IPS e.max CAD material had the least. TB had the highest ΔE1 value for all materials and DW had the lowest (P<.05). The brushing procedure caused the materials to return to their initial colors or reduce the color change in most groups. CONCLUSIONS: The presence of biofilm on CAD-CAM materials immersed in distilled water caused an unacceptable degree of discoloration (ΔE>1.8), and immersion in tea led to greater color change. The adhesion of biofilm to restorative dental materials plays an important role in the coloring of these dental materials.

A bibliometric and Altmetric analysis of the 100 top most cited articles on dentin adhesives.

OBJECTIVE: This study aimed to identify the 100 top-cited articles on dentin adhesives utilizing comprehensive bibliometric and altmetric analyses. MATERIALS AND METHODS: The Institute of Scientific Information Web of Knowledge database was used to compile the top-cited articles published from 1945 through February 12, 2023. Citation counts were manually retrieved for each article from Scopus, Google Scholar, Dimensions, and Altmetric. The articles were analyzed in terms of their number of citations, year, journal name, author (name, institution, and country), and type and specific field of study. We used descriptive statistics to summarize the results. RESULTS: The analysis revealed that the top 100 cited articles originated from 18 English-language journals and collectively accumulated a remarkable 34526 citations. The article with the highest number of citations garnered 1288 references. Among authors, Van Meerbeek B. stood out with nine articles and 4650 citations, followed by Pashley D.H. with six articles and 2769 citations. Japan was the leading contributor by country, while the Catholic University of Leuven led in terms of institutions with 20 articles. CONCLUSION: According to this study, basic research and review articles garnered the most citations, respectively. The citation analysis revealed different trends for researchers, the first being that researchers have focused on basic fields such as the ultramorphology of dentin and adhesive interfaces, followed by bond strength to dentin. Two studies on clinical experiences suggested that studies with high-level evidence, such as systematic reviews, meta-analyses, or randomized controlled clinical trials, are required. CLINICAL RELEVANCE: It is identified that more studies with high-level evidence-based research are needed in the field of dental adhesives.

The effect of different application modes of a 1-step self-etch adhesive on the clinical performance of Class I composite restorations: A randomized controlled clinical trial.

OBJECTIVE: To evaluate the clinical performance of a 1-step self-etch dentin adhesive that was applied according to the manufacturers' recommendations, doubling the adhesive application time and layer in Class I cavities with a composite resin. MATERIALS AND METHODS: A total of 39 patients aged between 14 and 43 (mean age: 19.1) years were enrolled in the study. Each patient received three restorations. In these three restorations, a 1-step self-etch adhesive was applied according to the manufacturer's recommendations (control group), by doubling the adhesive application time, and with double layers. The restorations were evaluated according to modified USPHS criteria at baseline, and 1, 2, 3, and 4-year recalls. RESULTS: After 4 years, the success rate was 100% for restorations with the adhesive applied according to the manufacturers' recommendations, 96.9% for restorations applied by doubling the adhesive application time, and 93.8% for restorations applied with double adhesive layers. There was no significant difference between the three application methods among all the evaluation periods regarding the evaluation criteria. CONCLUSIONS: The 4-year success rates of a 1-step self-etch dentin adhesive that was applied according to the manufacturers' recommendation, by doubling the adhesive application time, and with double layers were excellent. CLINICAL SIGNIFICANCE: It is not recommended to double the adhesive application time nor apply a double layer of a 1-step self-etch adhesive because it does not improve the clinical performance of Class I composite restorations.

Clinical Performance of Direct Composite Restorations in Patients with Amelogenesis Imperfecta - Anterior Restorations.

PURPOSE: To evaluate the clinical performance of direct composite restorations using nanohybrid and nanofill composite materials in anterior teeth in patients with amelogenesis imperfecta (AI). MATERIALS AND METHODS: The study included 15 patients with AI aged 14-30 years. During the study, the patients received anterior direct composite laminate veneer restorations using either a nanohybrid (Clearfil Majesty ES-2 and Clearfil Universal Bond, Kuraray Noritake) or a nanofill resin composite (Filtek Ultimate Universal Restorative and Single Bond Universal Adhesive, 3M Oral Care). The restorations were evaluated according to the modified USPHS criteria at baseline and at 1-, 2-, 3- and 4-year follow-up periods. RESULTS: The cumulative success rate of anterior restorations was 80.5% for nanohybrid and 92.5% for nanofill composite after 4 years. Eight restorations with nanohybrid and three restorations with nanofill resin composites failed. Ten restorations failed due to fracture; the fracture rate was 12.3%. Statistically significant differences were found between nanohybrid and nanofill composites regarding marginal discoloration and surface texture after 3 years. Furthermore, statistically significant differences were observed with respect to color match after 4 years. CONCLUSION: The use of a nanohybrid or nanofill composite for anterior direct restorations in patients with AI was observed to be satisfactory, based on the rate of ideal and clinically acceptable restorations. The primary reason for restoration failure was fracture. The failure rate of nanohybrid composite restorations was higher than with nanofill composite restorations with respect to survival and marginal adaptation criteria.

The prevalence, clinical features, and related factors of dentin hypersensitivity in the Turkish population.

OBJECTIVES: The purpose of this study was to identify the prevalence and predisposing and etiologic factors of dentin hypersensitivity (DH), as well as the demographic characteristics of patients. MATERIALS AND METHODS: The 1210 patients were examined. The research was based on a two-step investigation: questionnaire and clinical examination. DH was evaluated by the response of the patient to tactile and air-blast stimuli. Loss of attachment and gingival recession of sensitive teeth was measured on the buccal and lingual surfaces. Also, the tooth wear of sensitive teeth was graded on the buccal and lingual surfaces. Comparisons of nonnormally distributed continuous variables were performed using the Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA) and Dunn's post hoc test. Comparisons of categorical variables were performed using Pearson's chi-square, Fisher's exact chi-square, Yates's chi-square, and the Monte Carlo chi-square test. RESULTS: One hundred twenty-four patients reported DH, showing a prevalence for self-reported DH of 10.2%. Eight hundred forty teeth were diagnosed as having DH, giving a clinical diagnosis rate of DH of 29.4%. Females (76.8%), the 31-40 years age group (26%), housewives (36.8%), and high school education level (38%) had the highest prevalence of DH as demographic properties. A cold stimulus was the most common stimuli trigger for hypersensitivity (97.1%). Occasional pain (55.5%) showed the highest prevalence in terms of frequency of DH. A higher rate of DH was found with the use of medium brushes (47.4%) and brushing twice per day (59.4%) for 1-2 min (56.2%) with the circular method (33.8%) as oral hygiene habits. The buccal surface of the lower right central incisors (5.7%) had the highest prevalence. The most affected teeth by DH were incisors (38.4%). The buccal surfaces (86.3%) of teeth showed a higher high prevalence of DH compared with the lingual surface (52.7%), similar to gingival recession (40.9% vs. 15.7%) and loss of attachment (68.3% vs. 42.6%). CONCLUSIONS: Clinically diagnosed DH was more common than self-reported DH. Some factors related to patients such as sex (female), the 31-40 years age group, housewives, high school students, using medium brushes, brushing twice per day, and the circular brushing method were more likely to have a risk for DH. Also, buccal surfaces of teeth, gingival recession, and loss of attachment on the buccal surface of teeth should be considered as predisposing factors for DH. CLINICAL RELEVANCE: To control and prevent DH, clinicians should consider patients' demographics, predisposing factors, and etiologic factors.

Evaluation of fracture strength and total void amount in composite restorations on endodontically treated teeth / Resistencia a la fractura y la cantidad total de burbujas en resinas compuestas de dientes tratados endodónticamente

ABSTRACT: The aim of the study was to investigate the fracture strength of different composite resins and the quantity of voids in conventional posterior composite, high- flow flowable composite, bulk-fill flowable composite, and fiber-reinforced composite. Forty-four caries-free, freshly extracted mandibular premolars were used for this study. Teeth were prepared for cavity and root canal treatment. Subsequently, root canal treatment was applied to the teeth and cavities in order to prepare them for restorations. The specimens were then divided into four groups: group-1: Estelite Posterior; group-2: Estelite Flow Quick High Flow; group-3: Estelite Bulk-fill Flow; group-4: everX Posterior. One specimen from each experimental group was examined using micro-CT to perform measurement of voids. The fracture strength values of high-flow flowable, bulk-fill flowable, fiber-reinforced, and conventional micro- hybrid composites were found to be similar (p=0.497). EverX Posterior showed the highest fracture strength values (841.1±149.4 N), followed by Estelite Bulk-fill Flow (822.8±170.8 N). Volume of voids (%) obtained from Micro-CT analysis revealed that restorations with high-flow liner or bulk-fill flowable exhibited more voids. The fiber-reinforced composite showed the lowest percentage volume of incorporating voids and the highest fracture strength results.

RESUMEN: El objetivo del estudio fue investigar la resistencia a la fractura de diferentes resinas compuestas y la cantidad de burbujas en resinas posteriores convencionales, resinas fluidas de alto flujo, resinas fluidas tipo bulk-fill y resinas reforzados con fibras. Cuarenta y cuatro premolares mandibulares libres de caries, recién extraídos, fueron usados para este estudio. Los dientes se prepararon para el tratamiento de conductos radiculares y las cavidades para prepararlos para las restauraciones. Los especímenes se dividieron en cuatro grupos: Grupo-1: Estelite Posterior; Grupo-2: Estelite Flow Quick High Flow; Grupo-3: Estelite Bulk-fill Flow; Grupo-4: everX Posterior. Un espécimen de cada grupo experimental fue examinado usando micro-CT para realizar la medición de las burbujas. Los valores de resistencia a la fractura de los compuestos de alto flujo, flujo de relleno, reforzados con fibra y microhíbridos convencionales fueron similares (p=0,497). EverX Posterior mostró los valores más altos de resistencia a la fractura (841,1±149,4 N), seguido de Estelite Bulk-fill Flow (822,8±170,8 N). El volumen de las burbujas (%) obtenido del análisis de Micro-TC reveló que las restauraciones con revestimiento de alto flujo o con flujo de relleno a granel presentaban más huecos. El compuesto reforzado con fibra mostró el menor porcentaje de volumen de incorporación de vacíos y los resultados más altos de resistencia a la fractura.

Microtensile Bond Strength Between Self-Adhesive Resin Cements and Resin Based Ceramic CAD/CAM Block / Resistencia adhesiva microtensil entre cementos de resina autoadhesivos y bloques de cerámica CAD/CAM a base de resina

Abstract: Purpose: The objective of this study is to evaluate and compare the microtensile bond strength (μTBS) of four different self-adhesive resin cements to a resin-based ceramic CAD/CAM block, at the baseline, and after subjecting them to 5,000 thermo-cycles.Materials and Methods: Four self-adhesive dual-cured resin cements; G-CEM LinkAce (GC EUROPE, Leuven, Belgium), RelyX U200 (3M ESPE, Seefeld, Germany), Maxcem Elite (Kerr, CA, USA), TheraCem (Bisco, Schaumburg, USA) were applied to Cerasmart CAD/CAM blocks (GC EUROPE, Leuven, Belgium). CAD/CAM blocks were sectioned into sticks and subjected to µTBS tests at 24 hours, and the other half were subjected to tests after 5000 thermo-cycles. The data were tested by one-way variance analysis (p<0.05). Results: The highest bond strength values were observed in TheraCem, followed by G-CEM LinkAce and RelyX U200, respectively (p<0.05). At the baseline, G-CEM LinkAce, RelyX U200, and Maxcem Elite showed statistically similar results. After 5,000 thermal-cycles, a significant decrease was observed in the bond strength values of G-CEM LinkAce (p<0.05). Conclusion: Between the adhesive cements used in the study, TheraCem showed the highest micro-tensile bond strength values both in the baseline (24h) results, and after the 5,000 thermal- cycle aging procedures.

Resumen: Propósito: Evaluar y comparar la resistencia adhesiva microtensil (μTBS) de cuatro cementos de resina autoadhesivos diferentes con un bloque CAD/CAM de cerámica a base de resina, antes y después de 5.000 ciclos de termociclado. Materiales y métodos: cuatro cementos de resina de doble curado autoadhesivos; G-CEM LinkAce (GC EUROPE, Lovaina, Bélgica), RelyX U200 (3M ESPE, Seefeld, Alemania), Maxcem Elite (Kerr, CA, EE. UU.), TheraCem (Bisco, Schaumburg, EE. UU.) fueron aplicados a bloques Cerasmart CAD/CAM (GC EUROPE, Lovaina, Bélgica). Los bloques CAD/CAM se seccionaron en barras y se sometieron a pruebas µTBS a las 24 horas, y la otra mitad se sometió a pruebas después de 5000 ciclos térmicos. Los datos fueron probados por análisis de varianza unidireccional (p<0.05). Resultados: Los valores más altos de fuerza de unión se observaron en TheraCem, seguido de G-CEM LinkAce y RelyX U200, respectivamente (p<0.05). En la línea de base, G-CEM LinkAce, RelyX U200, Maxcem Elite mostró resultados estadísticamente similares. Después de 5.000 procesos de ciclo térmico, se observó una disminución significativa en los valores de resistencia de la unión de G-CEM LinkAce (p<0.05). Conclusión: entre los cementos adhesivos utilizados en el estudio, TheraCem mostró los valores más altos de resistencia de la unión micro-extensible tanto en la línea de base (24 h) como después de 5,000 procedimientos de envejecimiento térmico.

Does Q-MIX pretreatment improve the dentin bond durability of a two-step self-etch adhesive?

This study aims to analyze and assess the effects of three particular dentin pretreatment solutions on the bond durability of a two-step self-etch adhesive (Optibond XTR) applied to dentin after ageing for 2 years. Thirty-five third molars which were extracted (n = 5 for µTBS, n = 2 for nanoleakage) were divided into five groups: Group 1:Control (no pretreatment), Group 2:17% EDTA, Group 3:2% CHX, Group 4:17% EDTA plus 2% CHX, Group 5: Q-Mix. After the pretreatments of dentin, the dentin adhesive was applied as per the guidelines provided by the manufacturer. Half of the specimens were subjected to µTBS tests for 24 hr, while the remaining half were subjected to the tests after being kept for 2 years in water storage. Also, nanoleakage was evaluated with FE-SEM by examining silver nitrate deposits. The data obtained were evaluated using a two-way analysis of variance and Tukey Post Hoc test. The dentin pretreatments did not affect the 24 hr and 2 years µTBS values for OptiBond XTR. At 24 hr, the EDTA + CHX group (50.3 ± 4.9) showed that the highest µTBS value was obtained. Water ageing significantly reduced the µTBS results and after 2 years the highest µTBS value was obtained from the Q-Mix group (37.7 ± 5.2). Different dentin pretreatments do not alter the 24-hr µTBS and were not able to preserve the bond strength after 2 years of ageing. Q-Mix was able to slow down the regression in the strength of the dentin bond as well as nanoleakage over time.

The Effects of Various Polishing Procedures on Surface Topography of CAD/CAM Resin Restoratives.

PURPOSE: To investigate the effects of different polishing procedures on surface properties of CAD/CAM resin blocks. MATERIALS AND METHODS: In this study, three different CAD/CAM restorative materials (Cerasmart, Lava Ultimate and Shofu Block HC) were used. CAD/CAM blocks were cut in 3-mm-thick slabs and divided into 5 groups. Group-1: Glaze; Group-2: Two-step Diamond Polisher; Group-3: One-step Diamond Polisher; Group-4: Three-step Diamond Polisher; Group-5: Polishing Discs+Diamond Paste. After polishing, top surfaces of the samples were prepared to screen by noncontact laser profilometer (Nanovea) for measurements. Data were analyzed using two-way analysis of variance (ANOVA). RESULTS: The arithmetical mean deviation of the profile was defined as Ra. The extension of Ra (a line's arithmetical mean height) to a surface was defined as Sa. Compared to the arithmetical mean of the surface, Sa expresses the difference in terms of each point's height as an absolute value. Sa was commonly used to assess surface roughness. The highest surface roughness (Ra) values in this study were 0.313 ± 0.05 for Cerasmart, 0.433 ± 0.10 for Lava Ultimate and 0.320 ± 0.05 for Shofu Block HC. The specimens in Group-4 displayed higher Ra values than other groups for each CAD/CAM material. According to surface topography (Sa) values, highest values were 2.936 ± 1.25 for Cerasmart, 2.633 ± 1.28 for Lava Ultimate and 3.489 ± 0.57 for Shofu Block HC. For Cerasmart, LAVA Ultimate and Shofu blocks, Group-1 exhibited significantly higher Sa values than other groups (p < 0.001). CONCLUSION: Optiglaze Color, Sof-Lex Diamond and Identoflex Diamond Ceramic Polisher create smooth CAD/CAM resin surfaces. However, surface roughness values of Cosmedent Nano/Microhybrid Diamond and Diapolisher Paste applied specimens were high. According to Sa values, highest roughness values belong to Optiglaze Color.

Cytotoxic effects of different self-adhesive resin cements: Cell viability and induction of apoptosis.

PURPOSE: The effects of four different self-adhesive resin cement materials on cell viability and apoptosis after direct and indirect exposure were evaluated using different cell culture techniques. MATERIALS AND METHODS: Self-adhesive cements were applied to NIH/3T3 mouse fibroblasts by the extract test method, cell culture inserts, and dentin barrier test method. After exposure periods of 24 h and 72 h, the cytotoxicity of these self-adhesive materials was evaluated using the MTT assay (viability) and the Annexin-V-FITC/PI staining (apoptosis). RESULTS: The lowest cell viability was found in cells exposed to BeautiCem SA for 24 h in the extract test method. Cell viability was reduced to 70.6% compared to negative controls. After the 72 h exposure period, viability rate of cell cultures exposed to BeautiCem SA decreased more than 2- fold (29.5%) while cells exposed to RelyX U200 showed the highest viability rate of 71.4%. In the dentin barrier test method, BeautiCem SA induced the highest number of cells in apoptosis after a 24 h exposure (4.1%). Panavia SA Cement Plus was the material that caused the lowest number of cells in apoptosis (1.5%). CONCLUSION: The used self-adhesive cements have showed different cytotoxic effects based on the evaluation method. As exposure time increased, the materials showed more cytotoxic and apoptotic effects. BeautiCem SA caused significantly more severe cytotoxic and apoptotic effects than other cements tested. Moreover, cements other than BeautiCem SA have caused necrotic cell death rather than apoptotic cell death.

Clinical Performance of Direct Posterior Composite Restorations with and without Short Glass-fiber-reinforced Composite in Endodontically Treated Teeth: 3-year Results.

PURPOSE: To evaluate the clinical performance of direct posterior composite restorations with and without short glass-fiber (SGF) reinforced composite in endodontically treated teeth. MATERIALS AND METHODS: Twenty-four patients (mean age 32.5 years) were included in the study and two molars of each patient received endodontic treatment. After endodontic treatment, one tooth was restored with G-aenial Bond/fiber-reinforced composite (everX Posterior GC) using a microhybrid composite (G-aenial Posterior), and the other tooth was restored with G-aenial Bond/microhybrid composite (G-aenial Posterior). The modified USPHS criteria were used to evaluate the restorations at baseline, 1-, 2-, and 3-year follow-ups. RESULTS: The success rate of the everX Posterior and G-aenial Posterior restorations after 3 years was 78.3% and 91.3%, respectively. Five everX Posterior restorations and two G-aenial Posterior restorations failed. Based on the criteria used in this study, no significant differences between the two restorations were found at any evaluation time. CONCLUSION: All restorations showed acceptable clinical performance regarding all evaluation criteria, apart from the failed restorations. The main cause of restoration failure was restoration fracture. The failure rate of everX Posterior restorations was higher than G-aenial Posterior restorations.

Microtensile Bond Strength of CAD/CAM Resin Blocks to Dual-Cure Adhesive Cement: The Effect of Different Sandblasting Procedures.

PURPOSE: To investigate the effect of sandblasting powder particles on microtensile bond strength (µTBS) of dual-cure adhesive cement to CAD/CAM blocks. MATERIALS AND METHODS: CAD/CAM blocks (Cerasmart, VITA, and LAVA) were cut in slabs and divided into groups: group 1, no sandblasting; group 2, sandblasted with 27-µm Al2 O3 ; group 3, sandblasted with 30-µm CoJet; group 4, sandblasted with 50-µm Al2 O3 . After sandblasting, all specimens were silanized and luted using dual-cure adhesive cement (G-CEM LinkForce). After 24 hours, bonded specimens were cut into 1 ± 0.2 mm2 sticks, and µTBS values were obtained (N = 30). Additionally, 132 CAD/CAM block sections were prepared for surface roughness testing and scanning electron microscopy (SEM) evaluations. Results were analyzed using Kruskal-Wallis One-way ANOVA and Dunn's Post Hoc Test (p < 0.05). RESULTS: Group 1 exhibited significantly lower µTBS than the other groups (p < 0.05). The highest bond strength values were obtained from group 4 (p > 0.05). For LAVA, µTBS values of specimens that were sandblasted with 50-µm Al2 O3 powder were significantly higher than 30-µm-SiO2 and 27-µm Al2 O3 (p < 0.05). CONCLUSIONS: The sand particles investigated (27-µm Al2 O3 , 30-µm SiO2 , or 50-µm Al2 O3 ) did not significantly affect µTBS results of CAD/CAM blocks for Cerasmart and VITA, although the results changed significantly for LAVA. The ideal bond protocol for CAD/CAM blocks is specific to the material used.

The effect of sandblasting duration on the bond durability of dual-cure adhesive cement to CAD/CAM resin restoratives.

PURPOSE: To evaluate the effect of prolonged sandblasting on the bond durability of dual-cure adhesive resin cement to computer-aided design and computer-aided manufacturing (CAD/CAM) restoratives. MATERIALS AND METHODS: Nano-ceramic LAVA Ultimate and hybrid-ceramic VITA Enamic CAD/CAM blocks were used for this study. Each CAD/CAM block was sectioned into slabs of 4-mm thickness for the microtensile test (µTBS) test and 2-mm thickness for the surface roughness test. Three groups were created according to the sandblasting protocols; group 1: specimens were sandblasted for 15 seconds, group 2: specimens were sandblasted for 30 seconds, and group 3: specimens were sandblasted for 60 seconds. After sandblasting, all specimens were luted using RelyX Ultimate Clicker. Half the specimens were subjected to µTBS tests at 24 hours, and the other half were subjected to tests after 5000 thermocycles. Additionally, a total of 96 CAD/CAM block sections were prepared for surface roughness tests and scanning electron microscopy (SEM) evaluations. The Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance, and Dunn's post hoc test were used to compare continuous variables among the groups. RESULTS: At baseline, group 1, group 2, and group 3 exhibited statistically similar µTBS results for LAVA. However, group 3 had significantly lower µTBS values than groups 1 and 2 for VITA. After 5000 thermocycles, µTBS values significantly decreased for each block (P<.05). CONCLUSION: It is important to perform controlled sandblasting because it may affect bond strength results. Sixty seconds of sandblasting disturbs the initial µTBS values and the stability of adhesion of CAD/CAM restoratives to dual-cure adhesive resin cement for VITA Enamic.

The effect of glazing and aging on the surface properties of CAD/CAM resin blocks.

PURPOSE: To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. MATERIALS AND METHODS: Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad Säckingen, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness (Ra and Rz) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post-hoc test (P<.05). RESULTS: LAVA, VITA, and Cerasmart exhibited statistically similar Ra and Rz values for each group (P>.05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher Ra values than Group 2 (P<.05). Group 1 (0.502 Ra), Group 2 (0.384 Ra), and Group 3 (0.431 Ra) exhibited statistically similar Ra values for LAVA (P=.062). After 5000 thermocycles, surface roughness values did not change significantly for glazed LAVA, VITA, and Cerasmart (P>.05). CONCLUSION: Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

Microhybrid versus nanofill composite in combination with a three step etch and rinse adhesive in occlusal cavities: five year results.

OBJECTIVES: The aim of the study was to evaluate the 5-year clinical performance of occlusal carious restorations using nanofill and microhybrid composites, in combination with 3-step etch-and-rinse adhesives, in patients who were going to commence orthodontic treatment. MATERIALS AND METHODS: A total of 118 restorations for occlusal caries were conducted prior to orthodontic treatment. Occlusal restorations were performed both with Filtek Supreme XT (3M ESPE) and Filtek Z250 (3M ESPE) before beginning orthodontic treatment with fixed orthodontic bands. Restorations were clinically evaluated at baseline and at 1, 2, 3, 4, and 5-year recalls. RESULTS: None of the microhybrid (Filtek Z250) and nanofill (Filtek Supreme XT) composite restorations was clinically unacceptable with respect to color match, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, or surface texture. A 100% success rate was recorded for both composite materials. There were no statistically significant differences in any of the clinical evaluation criteria between Filtek Z250 and Filtek Supreme XT restorations for each evaluation period. CONCLUSIONS: The composite restorations showed promising clinical results relating to color matching, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, and surface texture at the end of the 5-year evaluation period.

The effect of double-coating and times on the immediate and 6-month dentin bonding of universal adhesives.

OBJECTIVE: The purpose of this study was to evaluate the effect of double-application coats and times on microtensile bond strength (µTBS) and adhesive-dentin interfaces created by dentin adhesive systems after 6 months of storage in water. MATERIALS AND METHODS: Two-hundred sixteen extracted non-carious human third molars were selected for the study. Single-Bond Universal (SU) and All-Bond Universal (AU), Adper Easy One (Eo) Self-Etch adhesive and Adper Single-Bond 2 (Sb) etch-and-rinse adhesive were applied to a flat dentin surface using three methods (1): dentin adhesives were applied as recommended by the manufacturers; (2): two consecutive coats of dentin adhesives were applied before photo-polymerization; and (3): a single coat of adhesive was applied but with twice the manufacturers recommended application time. Microtensile bond strength was determined either immediately or after 6 months of water storage. Data were analyzed using one-way analysis of variance and Tukey's post-hoc tests. RESULTS: At 24 h, groups 1, 2, and 3 exhibited statistically similar results for all dentin adhesive systems. For AU-Er, group 3 showed significantly higher bond strength than all group of AU-Se after 6 months. CONCLUSION: Universal adhesives seemed more stable against water degradation than traditional two-step etch-and-rinse and all-in-one systems within the 6-month period.

Flexural strength and microhardness of anterior composites after accelerated aging.

BACKGROUND: This study aimed to evaluate the flexural strength and microhardness of three different anterior composites after 10 000 thermocycles. MATERIAL AND METHODS: The mechanical properties of a nano-fill composite (Filtek Ultimate Universal Restorative (FUR) (Enamel)), a nano-hybrid composite (Clearfil Majesty ES2 (ES2) (Enamel)), and a micro-hybrid composite (G Aenial Anterior (GAA)) were investigated in this study. For the microhardness test, 8-mm diameter and 2-mm thickness composite discs were used (n = 10), and for the flexural strength test, 25x2x2 mm bar-shaped specimens were prepared (n = 13). The specimens were tested at 24 h and after 10 000 thermocycles. Data were analyzed using two-way analysis of variance and the post-hoc Tukey test (p < .05). Correlations between hardness and flexural strength were calculated using Pearson's correlation analysis. RESULTS: There was a significant difference in the microhardness values of the materials (p < .05). FUR exhibited significantly higher microhardness than ES2 and GAA. However, the flexural strength of three composites was statistically similar at 24 h (p > .05). Pearson correlation analysis revealed that there was a negative relationship between the mean hardness and flexural strength values (correlation coefficient = -0.367, p = .043). After 10 000 thermocycles, microhardness values of each material and flexural strength of ES2 and GAA decreased significantly according to 24 h. CONCLUSIONS: The nano-fill composite FUR displayed significantly higher microhardness values. However, each resin composite was statistically similar for flexural strength values. Ten thousand thermocycles significantly affected microhardness and flexural strength. Key words:Flexural strength, microhardness, anterior composites.

The effect of surface sealant application and accelerated aging on posterior restorative surfaces: An SEM and AFM study.

The purpose of this study was to evaluate the effect of surface sealant application and 10,000 thermocycles on the surface roughness and microhardness of different resin composite systems. A micro-hybrid (G Aenial Posterior), a nano-hybrid (Clearfil Majesty Posterior), a nano-fill (Filtek Ultimate Universal Restorative, Enamel Shade), and a bulk-fill resin composite (Filtek Bulk Fill Posterior Restorative) were used for the study. Specimens were evaluated at 24 h, after application of the surface sealant Fortify Plus, and after thermocycling. Data were analyzed using two-way repeated measures of analysis of variance (ANOVA) and a posthoc Bonferroni test (p<0.05). Surface roughness values of G Aenial Posterior and Filtek Ultimate Universal Restorative increased significantly after surface sealant application. However, neither surface sealant application nor thermocycling had a significant effect on composite microhardness values except Filtek Ultimate Universal Restorative (p>0.05).

Influence of polymerisation method and type of fibre on fracture strength of endodontically treated teeth.

The aim of this study was to investigate (i) the effect of direct or indirect polymerisation of adhesive-impregnated ribbon fibre under 4-mm bulk-filled composites on fracture strength; (ii) to compare polyethylene ribbon fibre-reinforcement composites with short fibre-reinforced composite; and (iii) the effectiveness of polyethylene ribbon fibre according to the restorative materials used (low-viscous bulk-fill composite, high-viscous flowable composite or conventional paste composite). Seventy molars were divided into seven groups; (groups 1-2) Ribbond-reinforced Surefil-SDR; (group 3) Ribbond-reinforced G Aenial Flo; (group 4) Ribbond-reinforced G Aenial Posterior; (group 5) short fibre-reinforced composite everX Posterior; (group 6) unfilled cavity; (group 7) intact teeth. Ribbond was adopted to cavity walls by impregnating an adhesive and using a flowable composite. In group 1, adhesive-impregnated Ribbond was polymerised directly using a light-curing-unit, and indirectly in group 2 under 4-mm bulk-filled composite. Direct or indirect polymerisation of adhesive impregnated ribbon fibre under 4-mm bulk-filled composite did not change the fracture strength results. Polyethylene ribbon fibre-reinforced groups (groups 1-4) and short fibre-reinforced composite group (group 5) displayed similar results. Polyethylene ribbon fibre can be used safely under 4-mm bulk-filled composites. Ribbond-reinforced low-viscous bulk-fill, high-viscous flowable, and conventional paste composite exhibited similar fracture strength results.

Influence of different composite materials and cavity preparation designs on the fracture resistance of mesio-occluso-distal inlay restoration.

The aim of the study to evaluate the fracture resistance of a computer-aided design/computer-aided manufacturing (CAD/CAM) and three indirect composite materials for three different mesio-occluso-distal (MOD) inlay cavity designs. A total of 120 mandibular third molar were divided into three groups: (G1) non-proximal box, (G2) 2-mm proximal box, and (G3) 4-mm proximal box. Each cavity design received four composite materials: Estenia, Epricord (Kuraray, Japan), Tescera (Bisco, USA), and Cerasmart CAD/CAM blocks (GC, USA). The specimens were subjected to a compressive load at a crosshead speed of 1 mm/min. The data was analyzed using the two-way analysis of variance and Bonferroni post hoc test (p<0.05). Estenia exhibited significantly higher fracture strength than Epricord and Cerasmart in G1. In G2 and G3, there was no significant difference among the four materials. Using a non-proximal box design for the cavity can improve the fracture resistance of the inlay restoration.