Effects of charcoal-based whitening toothpastes on human enamel in terms of color, surface roughness, and microhardness: an in vitro study.

OBJECTIVE: Charcoal based oral care products have gained popularity in the last few years. The aim of this in vitro study was to compare the effects of different charcoal based whitening toothpastes on color, surface roughness and microhardness of human enamel. MATERIALS AND METHODS: Forty-eight specimens obtained from human permanent upper incisor teeth were randomly divided into 4 groups(n=12):Group-1:Colgate Total 12(CT); Group-2:Body Kingdom(BK); Group-3:Black is White(BW), Group-4:Colgate optic white(COW). Following 4 days cycle of darkening(2-min chlorhexidine and 60-min black tea per day), a 12- week brushing(twice daily for 1 min)was performed. Color of specimens was measured using a spectrophotometer. A contact type profilometer was used to measure surface roughness (Ra) and Vicker's hardness tester was used for the changes in microhardness(VHN). A representative sample from each group was visualized by SEM. Data were analyzed by One-way ANOVA, Welch, Fisher's, Kruskall-Wallis, Wilcoxon Sign Rank and Paired t-tests(p<0.05). RESULTS: After 12- week brushing, no differences were found among the groups in terms of color change(p=0.989). All toothpastes tested showed no clinically acceptable whitening performances. A substantial increase in surface roughness was found in all groups, except BW(p<0.05). An increase was found in microhardness with CT(p=0.013), while no changes were found with BK, BW and COW(p>0.05).Only few scratches were observed on the enamel surfaces by SEM evaluations. CONCLUSION: Twelve week brushing with charcoal based whitening toothpastes and a regular fluoridated toothpaste presented similar effects in color of enamel. Surface roughness was increased(except BW) while microhardness was not affected(except CT) with charcoal based whitening toothpastes. CLINICAL RELEVANCE: Charcoal based whitening toothpastes do not promise to whiten the human permanent teeth and their effects on enamel abrasion should not be disregarded.

A randomized controlled 10 years follow up of a glass ionomer restorative material in class I and class II cavities.

OBJECTIVE: To evaluate the durability of a glass ionomer restorative material in Class I and Class II cavities during 10 years compared with a micro filled composite resin. METHODS: Fifty-nine participants (mean age 24 years) received 140 (80 Class I and 60 Class II) glass ionomer (GI) or composite resin (CR) restorations. Evaluation was performed with slightly modified USPHS criteria at baseline, and yearly during the 10 years. Data were analyzed with Cohran's Q and McNemar's tests. RESULTS: Fifty-one patients and 124 restorations (61 GI / 38 Class I - 23 Class II, 63 CR / 38 Class I, 25 Class II) were evaluated after 10 years. The recall rate was 86.4%. The overall clinical recall rate of restorations was 88.6%. The success rate of Class I and II restorations were calculated as 100% for both materials. The cumulative failure rate (CRF) of all Cl I and Cl II GI restorations was 3.17% in total, but CFR was 8 % for Cl II GI restorations. A significant difference was observed between the marginal discoloration scores of restorations at 10 years (p = 0.022). No significant difference was seen between two restorative materials in terms of marginal adaptation (p > 0.05). A significant change was seen in color match of GI restorations at 10 years (p < 0.05). No significant change was found for the anatomical form, secondary caries, postoperative sensitivity, surface texture, and retention for either restorative material (p > 0.05). CONCLUSIONS: Both tested restorative materials showed an acceptable success rate in the restoration of Class I and Class II cavities during the 10-year follow up.

Comparison of two different methods of detecting residual caries.

OBJECTIVES: The aim of this study was to investigate the ability of the fluorescence-aided caries excavation (FACE) device to detect residual caries by comparing conventional methods in vivo. MATERIALS AND METHODS: A total of 301 females and 202 males with carious teeth participated in this study. The cavity preparations were done by grade 4 (Group 1, 154 teeth), grade 5 (Group 2, 176 teeth), and postgraduate (Group 3, 173 teeth) students. After caries excavation using a handpiece and hand instruments, the presence of residual caries was evaluated by 2 investigators who were previously calibrated for visual-tactile assessment with and without magnifying glasses and trained in the use of a FACE device. The tooth number, cavity type, and presence or absence of residual caries were recorded. The data were analyzed using the Chi-square test, the Fisher's Exact test, or the McNemar test as appropriate. Kappa statistics was used for calibration. In all tests, the level of significance was set at p = 0.05. RESULTS: Almost half of the cavities prepared were Class II (Class I, 20.9%; Class II, 48.9%; Class III, 20.1%; Class IV, 3.4%; Class V, 6.8%). Higher numbers of cavities left with caries were observed in Groups 1 and 2 than in Group 3 for all examination methods. Significant differences were found between visual inspection with or without magnifying glasses and inspection with a FACE device for all groups (p < 0.001). More residual caries were detected through inspection with a FACE device (46.5%) than through either visual inspection (31.8%) or inspection with a magnifying glass (37.6%). CONCLUSIONS: Within the limitations of this study, the FACE device may be an effective method for the detection of residual caries.

The effect of three different mouthrinses on the surface hardness, gloss and colour change of bleached nano composite resins.

This in vitro study evaluated the effects of three mouthrinses (Listerine--alcohol containing, Oral B--alcohol free and Rembrandt Plus--peroxide whitening rinse) on the surface hardness, gloss and colour of a nanofill (Filtek Supreme) and nanohybrid (Simile) composite resin that had been subjected to bleaching treatment. 30 specimens of each material were fabricated and randomly divided into three groups of 10. The hardness, gloss and CIE Lab colour parameters of each specimen were assessed prior to the experiments. Specimens were exposed to the 10% carbamide peroxide bleaching agent (Vivastyle) for 2 hours per day for 14 days. Following the bleaching treatment measurements were repeated. The specimens were then conditioned with mouthrinses for 12 hours which was equivalent in time to 1 year of two minutes daily use. The specimens were measured again for hardness, gloss and colour and data were subjected to the statistical analysis. The result of this study showed no statististical difference between the restorative materials after bleaching and the use of mouthrinses (p > 0.05). Bleaching treatment and the use of mouthrinses af fected the hardness, gloss and colour of both resins. Significant differences were observed with the use of mouthrinses for all parameters (p < 0.05). Rembrandt Plus promoted the greatest changes, followed by Listerine and Oral B.