The effect of a universal cleaning agent on the bonding performance of a self-adhesive cement to contaminated dentin surfaces.

PURPOSE: This study examined the effect of using KATANA Cleaner (KC) containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) salt on the micro-shear bond strength (µSBS) of a self-adhesive cement to uncontaminated and contaminated dentin. METHODS: Dentin samples were categorized into four contamination conditions (no contamination, saliva, blood, saliva/blood mixed) and subjected to two decontamination methods (water rinse and KC use), forming eight groups. Scanning electron microscope images representing each group were obtained. One sample representing each group was analyzed by Raman Spectroscopy. Composite resin was bonded to the sample dentin surfaces with a self-adhesive resin cement. After 5,000 thermal cycles, the µSBS test was performed. The data were analyzed statistically (α= 0.05). RESULTS: The lowest µSBS value was observed in the water-rinsed mixed contamination group, while the highest was in the KC-treated uncontaminated group. KC-treated groups exhibited significantly higher µSBS values compared to water-rinsed groups for each contamination type (P< 0.05), indicating the efficacy of KC in enhancing bond strength. CLINICAL SIGNIFICANCE: There are limited studies using the new MDP salt-containing cleaner on dentin. In this study, contamination of dentin tissue with saliva, blood, and saliva/blood mixture was simulated and the effects of water rinsing and MDP salt-containing cleaner (KATANA Cleaner) on bond strength were tested as decontamination methods. The results showed that the use of a cleaner containing MDP salt increased the bond strength to dentin tissue under both non-contaminated and contaminated conditions.

A comparison of polishing systems and thermal cycling on the surface roughness and color stability of a single-shade resin composite.

PURPOSE: To evaluate the surface roughness and color stability of a single-shade composite resin after thermal cycling with different finishing and polishing systems. METHODS: A total of 91 specimens were prepared with standard molds using a single-shade resin composite Omnichroma. The specimens were randomly separated into seven groups: Control (Mylar strip only), grit (600 grit SiC abrasive paper), OneGloss, Clearfil Twist Dia, Sof-Lex Diamond Polishing System, EVE Diacomp Plus Twist, and OptiDisc. The top surface of each specimen was polished per the manufacturers' directions. After initial measurements, 10,000 and 50,000 thermal cycles were performed. After each thermal cycling, the measurements were retaken. A generalized linear model analysis was used to compare the values, and multiple comparisons were performed with the Bonferroni correction. RESULTS: Different finishing and polishing systems and thermal cycling significantly affected the surface roughness and color change of the single-shade composite resin (P< 0.001). The smoothest surfaces were obtained with the Sof-Lex Diamond Polishing System, while the group polished with Clearfil Twist Dia showed the least color change. CLINICAL SIGNIFICANCE: The surface roughness of the single-shade resin composite exhibited acceptable values for all polishing systems tested. The color change values of the single-shade resin composite were found to be above the acceptable value for all polishing systems, but the two-step spiral polishing systems performed better in terms of color stability.

Surface roughness of different types of resin composites after artificial aging procedures: an in vitro study.

BACKGROUND: The temperature changes, chemical agents, and brushing activity that resin composite restorations are exposed to in the oral environment can cause changes in surface roughness. In this study, the aim was to investigate in vitro the clinical one-year surface roughness changes of different types of composites (flowable or conventional) from the same companies by subjecting them to immersion in solutions, brushing, and thermal cycling procedures to simulate intraoral conditions. METHODS: Four different resin composite brands were included in the study using both their conventional (Charisma Smart, 3M Filtek Ultimate Universal, Omnichroma, Beautifil II) and flowable resin composites (Charisma Flow, 3M Filtek Ultimate Flowable, Omnichroma Flow, Beautifil Flow Plus F00), giving 4 groups with 2 types of resin composite in each. 40 samples were prepared for each group/resin type, for a total of 320 samples. After initial surface roughness measurements by a mechanical profilometer, the samples were divided into 4 subgroups (n = 10) and immersed in solutions (distilled water, tea, coffee, or wine) for 12 days. The samples were then subjected to 10,000 cycles of brushing simulation and 10,000 cycles of thermal aging. Surface roughness measurements were repeated after the procedures. For statistical analysis, the 3-way analysis of variance and the Tukey test were used (p < 0.05). RESULTS: It was concluded that composite groups and types had an effect on surface roughness at time t0 (p < 0.001). At time t1, the highest surface roughness value was obtained in the Beautifil-conventional interaction. When the surface roughness values between time t0 and t1 were compared, an increase was observed in the Beautifil II and Beautifil Flow Plus F00, while a decrease was observed in the other composite groups. CONCLUSION: Composite groups, types, and solutions had an effect on the surface roughness of resin composites. After aging procedures, it was concluded that the Beautifil group could not maintain the surface structure as it exceeded the threshold value of 0.2 µm for bacterial adhesion.

Evaluation of Turkish Dentists' Approach to Over-the-Counter Whitening Agents: A Questionnaire-Based Study.

AIM: Over-the-counter teeth-whitening products have become popular in accordance with the increasing demands of patients. These products can also be recommended to patients by dentists. The aim was to determine the rates of recommendation of over-the-counter teeth whitening products by dentists in Turkey divided into different categories for their patients and to interpret them based on a cause-and-effect relationship. MATERIAL AND METHODS: After obtaining ethics committee approval, the survey questions were created using Google Forms (Google Inc., Mountainview, CA) and delivered to dentists via social media. Dentists who signed the informed consent form completed the survey. Within the study's scope, statistical analyses were conducted using IBM SPSS Statistics for Windows, version 26.0 (IBM Corp., Armonk, NY). Values were expressed as frequency (n) and percentage (%). A chi-square test was used to compare participants' teeth-whitening recommendations according to their demographic characteristics. The statistical significance level was accepted as p <0.05 throughout the study. RESULTS: A total of 57.9% of dentists working in Turkey did not recommend over-the-counter teeth-whitening products to their patients. When the answers to the question "Which whitening products sold on the market do you recommend to your patients?" were compared according to the participants' place of work, there was a statistically significant difference between the place of work and the recommended whitening product (p <0.05). Participants working in the private sector answered "I do not recommend" at a higher rate than participants working in the public sector. Among those who recommended toothpaste, more dentists with five or fewer years of experience recommended toothpaste to their patients than dentists with greater than five years of experience. Additionally, more dentists working in the public sector recommended toothpaste to their patients than dentists working in the private sector, and more specialist dentists recommended toothpaste to their patients than general practitioner dentists. CONCLUSION: Most dentists in Turkey do not recommend over-the-counter teeth-whitening products to their patients. Among those who recommend such products, toothpaste has been determined to be the first choice. The results of this study may raise awareness among dentists about over-the-counter teeth-whitening products and encourage new studies.

Effect of rotation frequency of polishing discs on the surface roughness of resin composite material.

The aim of this study was to evaluate the effect of rotation frequency (rpm) of different polishing discs on the surface roughness of a nanohybrid resin composite material. 126 specimens were prepared in metal molds of 10 mm diameter and 2 mm depth using a nanohybrid resin composite material. The prepared specimens were kept in distilled water for 24 hours. Polishing treatments at 5k, 10k, 15k, and 20k rpm were applied to the nanohybrid resin composite material by grouping different brand polishing discs: Sof-Lex Contouring and Polishing Discs (3M Espe, USA) (3M Group), Optidisc (Kerr Corporation, USA) (Kerr Group), Super-Snap Rainbow Technique Kit (Shofu Dental, Japan) (Shofu Group), Finishing Disc (Bisco Dental, USA) (Bisco Group). The surface roughness was evaluated at three different points by atomic force microscopy for all specimens and scanning electron microscopy was used for visual assessment. Data were evaluated by Two Way ANOVA and Tukey's HSD Test. The mean surface roughness (Ra, µm) of all prepared samples showed significant differences (α = 0.05). According to Two-Way ANOVA, there is a statistically significant relationship between the rpm values and the discs. The 3M group showed the highest roughness value at all rpm speeds. Shofu group at 15k, 20k rpm, Bisco group at 10k, 15k, 20k rpm, the Kerr group at 15k, 20k rpm showed the lowest roughness value and had roughness close to the surfaces finished with a mylar strip. The smoothest surfaces were obtained at 15k rpm, even though polishing discs from different brands were used. It was also observed that 5k and 20k rpm polishing speeds can increase the surface roughness of the nanohybrid resin composite material.

The Effect of Whitening Toothpastes on the Color Stability of a Smart Monochromatic Composite Resin.

OBJECTIVE: The aim of this study was to evaluate the color stability of smart monochromatic composite resin after coloring with coffee solution, thermal aging and brushing with four different kinds of toothpaste. MATERIALS AND METHODS: According to the manufacturer's instructions, 40 smart monochromatic composite resin (Omnichroma, Tokuyama Dental, Japan) specimens were prepared with a thickness of 2 mm and a diameter of 10 mm. The samples were divided into four groups. The first group (SFM) was brushed with Sensodyne Fresh Mint (Sensodyne GSK, UK), the second group (CW) with Colgate 2 in 1 Whitening (Colgate Palmolive, USA), the third group (OW) with Opalescence Whitening (Ultradent Products, Inc., USA), the fourth group (COW) with Colgate Optic White With Charcoal (Colgate Palmolive, USA). At time point t0, no brushing and thermal cycles were performed. For time point t1, simulations corresponding to 10 days of staining, thermal aging and brushing were performed. For time point t2, simulations corresponding to one year of staining, thermal aging and brushing were performed. The color of all specimens was measured at t0, t1 and t2 with a spectrophotometer. To examine the color change, ΔE00 values were calculated with the CIEDE 2000 color system. Shapiro Wilk, Kolmogorov Smirnov, Wilcoxon Signed Rank, Kruskal Wallis, and Mann-Whitney U tests were used to analyze the data. RESULTS: According to the results of the intergroup comparison, there is no statistically significant difference between the groups in ΔE00(t0-t1) values in terms of t0-t1 time period measurement (p>0.05). There is a statistically significant difference between the groups in ΔE00(t1-t2)values in terms of t1-t2 time period measurement (p<0.05). The COW group had the lowest ΔE00(t1-t2) value and the OW group had the highest ΔE00(t1-t2) value. There is a statistically significant difference between the groups in ΔE00 (t0-t2) values in terms of t0-t2 time period measurement (p<0.05). The COW group had the lowest ΔE00(t0-t2) value and the OW group had the highest ΔE00(t0-t2) value. CONCLUSION: The whitening efficacy of different kinds of toothpaste whitening mechanisms may differ from each other. Toothpastes also show whitening on composite resins. The lowest discoloration was observed in the group brushed with toothpaste containing activated charcoal and blue covarine. The efficacy of whitening toothpastes should be supported by in vivo studies.

A Comparative Study of the Repair Bond Strength of New Self-Adhesive Restorative Materials With a Resin Composite Material.

AIM: The aim of the present study is to compare the repair bond strengths (RBSs) of Cention-N (light-cure and self-cure modes), Equia Forte HT Fil and a nanohybrid resin composite. MATERIALS AND METHODS: Equia Forte HT Fil (GC, Tokyo, Japan), Cention-N (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Z550 (3M ESPE, St Paul, MN, USA) were used in this study. Equia Forte HT Fil (EQF), Cention-N self-cure (CSC), Cention-N light-cure (CLC) and Filtek Z550 (Z550) groups were formed. A total of 40 samples were prepared; 10 samples in each group (n = 10). After the polymerization was completed according to the manufacturer's instructions, the samples were polished with OptiDisc (Kerr Corporation, Orange, USA) for 5 s each, from extra-course to extra-fine. After all samples were stored in 37°C water for 24 h, 10,000 cycles of brushing simulator and thermal cycles were applied to the samples. The samples were prepared in accordance with the selected repair protocol, and microshear bond strength (µSBS) test was performed. Fracture analysis on debonded surfaces was visualized by scanning electron microscopy. The conformity of the data to normal distribution was analyzed by the Shapiro-Wilk test. Multiple comparisons were performed using Dunn's test. RESULTS:  Z550 showed significantly higher µSBS as compared to the other three groups. There is no difference between CSC, CLC and EQF. CONCLUSION: The use of Cention-N's self-cure or light-cure mode did not affect the RBS values. The RBS values of Cention-N and Equia Forte HT Fil materials are lower than those of the composite resin material.

Effect of different polishing systems and speeds on the surface roughness of resin composites.

Aims and Objectives: The objective of this study was to compare surface roughness of a nano-spherical resin composite using four different multi-step polishing disc systems at five different speeds. Materials and Methods: In total, 154 discs samples were prepared using a supra-nano spherical resin composite. The samples were divided into negative and positive control groups and the following four finishing and polishing disc systems: Sof-Lex, Bisco Finishing Discs, OptiDisc, and Super-Snap. Each polishing disc system was applied at five different speeds (2000, 5000, 10,000, 15,000, and 20,000 revolutions per minute [RPM]) (n = 7). The surface roughness of samples was measured using a profilometer. One sample from each group was evaluated by scanning electron microscopy and atomic force microscopy. Two-way analysis of variance was used to evaluate the average roughness (Ra) data from the profilometric experiments using statistical software (GraphPad Prism4-GraphPad Software; La Jolla, CA, USA). The mean values were compared using the Bonferroni test (P = 0.05). Results: The mean roughness ranged from 0.07 µm to 0.41 µm. The smoothest surfaces were obtained with OptiDisc at 20,000 RPM and Super-Snap at 20,000 RPM. The Bisco Finishing Discs group at 2,000 RPM showed the highest surface roughness values. For all polishing systems, the roughness at 20,000 RPM was lower than that at other speeds. Conclusion: Within the limitations of the present in vitro study, it can be concluded that the polishing performance was in the following order: Super-Snap > OptiDisc > Sof-Lex > Bisco Finishing Discs. In addition, the surface roughness decreased as the polishing speed increased.