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.

Delayed vs. immediate placement of restorative materials over Biodentine and RetroMTA: a micro-shear bond strength study.

BACKGROUND: The aim of the present study was to investigate the micro-shear bond strength (µSBS) of various restorative materials applied on two different fast-setting calcium silicate-based materials and to evaluate the effect of restoration time on µSBS. METHODS: A total of 180 acrylic blocks with a cavity in the center were randomly divided into 2 main groups according to the capping material to be used (Biodentine or RetroMTA). The specimens were also randomly divided into 3 groups according to the restoration time (3 min, 12 min, 24 h). After the specified waiting periods, glass hybrid material (EQUIA Forte HT), resin composite (Filtek Z550) and light-cured calcium silicate material (Theracal LC) were placed on the specimens with tygon tubes. The specimens were kept for 24 h and then subjected to µSBS test. Statistical analysis was performed by 3-way ANOVA followed by Tukey test for pairwise comparisons (α = 0.05). RESULTS: There is a statistically significant difference (p < 0.05) between the µSBS values obtained by applying resin composite on RetroMTA after different setting times (24 h > 12 min > 3 min). The µSBS obtained for the Biodentine-resin composite at the end of the 3 min setting time is significantly lower (p < 0.05) than the µSBS values at 12 min and 24 h. For both calcium silicate cements, at the end of all time periods, the µSBS obtained when resin composite was applied at the end was higher than the other materials (p < 0.05). CONCLUSIONS: For Biodentine-resin composite bonding, the manufacturer's recommendation of 12 min can be considered an appropriate time, whereas for RetroMTA-resin composite bonding, the µSBS increased as the waiting time increased. Regardless of the waiting time, it is recommended to prefer direct composite resin restoration over Biodentine and RetroMTA.

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.

Micro shear bond strength of mineral trioxide aggregate to different innovative dental restorative materials.

The objective of this in vitro study was to investigate the micro shear bond strength (µSBS) of mineral trioxide aggregate to four different restorative materials. Sixty mineral trioxide aggregate (MTA) samples were randomly assigned into four experimental groups based on the restorative materials used: nanohybrid resin composite as a control, giomer, alkasite and ormocer. µSBS samples were prepared for each group (n = 15). These samples were then submitted to a µSBS test (crosshead speed, 0.5 mm/min). The resulting data were statistically analyzed by one-way analysis of variance (ANOVA), Levene, and Bonferroni tests (α = 0.05). The bond strength of the alkasite group was statistically significantly higher than all the tested groups (p<0.05), while there were no significant differences between the nanohybrid resin composite, giomer, or ormocer groups (p > 0.05). Within the limitations of this study, alkasite restorative material could be a promising material when placed over MTA.

The effects of applying a novel cleaner on the bonding strength of zirconia surfaces.

This study evaluates how pre-treatment with an MDP-containing cleaning agent (Katana Cleaner, Kuraray) influences the micro-shear bond strength (µSBS) of saliva-contaminated zirconia when used with universal adhesive (UA) systems. Rectangular specimens (2 mm × 12 mm × 15 mm) were obtained (IPS, e.max ZirCAD, MO, B65L17, Ivoclar Vivadent) and divided into three groups; a non-contaminated group (control group)(CON), a contaminated and cleaned with isopropyl alcohol group(ISP), and lastly, a group contaminated and cleaned with an MDP-containing cleaning agent(KAC). Each group was then subdivided into three subgroups according to the UAs used (n = 12). Composite cylinders were prepared and bonded to each surface with Panavia V5 (Kuraray, Noritake Dental). A µSBS test was performed and the data were evaluated with the two-way analysis of variance (two-way ANOVA) and multiple comparisons test (α = 0.05). The highest µSBS values were obtained in the non-contaminated group (p < 0.001), regardless of UAs. All subgroups showed lower µSBS values after saliva contamination, but KAC resulted in significantly higher µSBS values than 99% isopropanol (p < 0.001). Overall, the lowest µSBS value was obtained with 99% isopropanol. The KAC-Clearfil UA subgroup resulted in statistically significantly higher µSBS values than the other UAs (p = 0.035 and 0.007), although all three UAs resulted in sufficient µSBS values. This study revealed that applying KAC followed by a UA containing phosphate monomers produces promising results for improving µSBS values of zirconia, greater than results using 99% isopropanol.Clinical relevance: An MDP-containing cleaning agent followed by a phosphate monomer containing a universal adhesive is a promising method to obtain acceptable bonds with saliva-contaminated zirconia ceramics.

The effect of different energy levels of the Er: YAG laser on the repair bond strength of a nanohybrid composite resin.

This study evaluates the durability of repair microshear bond strength (µSBS) of nanohybrid composite resins which surfaces are treated with different laser parameters and bur. A total of 240 nanohybrid composite resin disk shaped specimens were prepared. Then, specimens were divided into eight test groups as regards to surface treatment types (Erbium (Er:YAG) laser with seven different parameters and bur). Half of the specimens in each group were subjected to 5000 thermal cycling (TC) and the other half to 20,000 TC. Universal testing machine was used for µSBS test. The data were analyzed with a two-way analysis of variance and Tukey test. Among the specimens treated with ER:YAG laser+5000 TC, we detected the highest mean µSBS test values in the subgroups L200 and L250. Among the specimens treated with ER:YAG laser+20,000 TC, the highest mean µSBS test values were seen in the L200 subgroup. The µSBS values after the 20,000 TC were significantly lower than those after 5000 TC for all different treatment types. Thermal cycling and laser energy levels have effects on repair µSBS. Considering the bond strength and durability it seems more effective to use Er:YAG laser at 200 mJ. To repair an aged nanohybrid composite resin, Er:YAG laser surface treatments may provide some benefits by acquiring a reliable bond strength with durability. This study may give information on which parameters are more suitable to use Er:YAG laser for the repair of nanohybrid composite resins.

Adhesive system affects repair bond strength of resin composite.

PURPOSE: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. MATERIALS AND METHODS: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. RESULTS: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001). No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001). CONCLUSION: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.