Esra Uzer Çelik

Effects of different antibacterial agents on enamel in a biofilm caries model

Using a mature biofilm model, the aim of this study was to evaluate the effectiveness of different antibacterial agents in comparison with silver diamine fluoride (SDF). Forty-eight saliva-coated enamel slabs were inoculated with Streptococcus mutans monospecies biofilm. The biofilms were then exposed to 10% sucrose in tryptone yeast-extract culture medium, 8 times per day for 7 days. After the biofilm growth period, the enamel slabs were treated with one of the following substances: 1) distilled water; 2) SDF; 3) acidulated phosphate fluoride (APF); 4) ammonium hexafluorosilicate (AHF); 5) ammonium hexafluorosilicate + cetylpyridinium chloride (AHF+CPC); or 6) 0.2% chlorhexidine (CHX). After these treatment procedures, the samples were incubated at 37ºC for 2 days, and the numbers of viable microorganisms in the biofilms were counted. The number of viable bacteria was significantly reduced by all of the antibacterial agents (P < 0.05). However, SDF showed the highest antibacterial activity (P < 0.05), and the effectiveness of the other agents was lower (P < 0.05). SDF has a highly effective antibacterial action against cariogenic Streptococcus mutans biofilm; none of the other fluoride agents used in this study, or 0.2 CHX agent, showed an antibacterial effect comparable to that of SDF.

A minimally invasive technique for the management of severely fluorosed teeth: A two-year follow-up

Objective: Severely fluorosed and heavily discolored teeth that have large enamel defects give rise to esthetic concerns and require permanent treatment. In such cases, restorative techniques such as porcelain or composite laminate veneers or crowns are generally preferred, in which tooth preparation is inevitably required. Materials and Methods: This clinical report describes a patient with severely fluorosed teeth who was successfully treated with a minimally invasive technique including enamel microabrasion (6.6% hydrochloric acid slurry with silicon carbide micro-particles, Opalustre, Ultradent Products, Inc., South Jordan, UT, USA) followed by in-office bleaching (38% hydrogen peroxide, Opalescence Boost, Ultradent). Enamel microabrasion was conducted in two visits while three visits were required for in-office bleaching. Patient was followed-up after 2 years. Result: A slight staining had occurred during this period, but it was acceptable for patient. No adverse effects were observed. Conclusions: The minimally invasive technique including enamel microabrasion and in-office bleaching was efficient and may represent a good alternative to traditional restorative techniques for the management of severely fluorosed teeth.

Effect of tooth discoloration severity on the efficacy and color stability of two different trayless at-home bleaching systems

Background. The use of trayless at-home bleaching agents in darker teeth is raising some concerns due to their unknown efficacy. The purpose of this in vitro study was to evaluate the effect of tooth discolouration severity on the efficacy and colour stability of two different trayless at-home bleaching systems. Methods. Ninety enamel-dentin samples were divided into two groups: lighter tand darker teeth. The teeth in each group were further divided into three groups (n=15): (1) tray-based system with 10% carbamide peroxide (Opalescence Oh) (control group); (2) a tray applied whitening membrane with 10% hydrogen peroxide (Treswhite Supreme); and (3) a whitening pen with 22% carbamide peroxide (Hollywood Smiles). After bleaching, the teeth were stained for 9 days using red wine. Colour readings before bleaching treatment were determined using a dental spectrophotometer and were repeated 24 h after bleaching treatment and 24 h after staining process. Analysis of variance, Bonferroni and Dunnett C tests were used at 5% significance level. Results. No differences were observed between the bleaching efficacy of Treswhite Supreme and Opalescence Oh in the lighter teeth, while Opalescence Oh had the best bleaching efficacy in the darker teeth (p<0.05). Hollywood Smiles had the worst bleaching efficay but the best color stability in both lighter and darker teeth (p<0.05). No differences were observed between the color stability values of Treswhite Supreme and Opalescence Oh. Conclusion. This study suggested that both the tooth discolouration severity and the type of trayless system used affected the bleaching efficacy, whereas only the type of trayless system affected the color stability.

Influence of blood contamination during multimode adhesive application on the microtensile bond strength to dentin

Objectives: The present study evaluated the effects of blood contamination performed at different steps of bonding on the microtensile bond strength (μTBS) of multimode adhesives to dentin when using the self-etch approach. Materials and Methods: Seventy-five molars were randomly assigned to three adhesive groups comprising 25 specimens each: two multimode adhesives [Single Bond Universal (SBU) and All-Bond Universal (ABU)] and a conventional one-step self-etch adhesive [Clearfil S3 Bond Plus (CSBP)]. Each group was subdivided as follows: (1) uncontaminated (control): bonding application/light curing as a positive control; (2) contamination-1 (cont-1): bonding application/light curing/blood contamination/dry as a negative control; (3) contamination-2 (cont-2): bonding application/light curing/blood contamination/rinse/dry; (4) contamination-3 (cont-3): bonding application/blood contamination/dry/bonding re-application/light curing; and (5) contamination-4 (cont-4): bonding application/blood contamination/rinse/dry/bonding re-application/light curing. Dentin specimens were prepared for μTBS testing after the composite resin application. Data were analyzed with two-way ANOVA and post-hoc tests (α = 0.05). Results: μTBS values were similar in cont-3 groups, and ABU/cont-4 and corresponding control groups, but were significantly lower in the other groups than in their control groups (P < 0.05). Cont-1 groups showed the lowest μTBS values (P < 0.05). Conclusions: Neither decontamination method prevented the decrease in μTBS when contamination occurred after light curing. Drying the blood contaminants and reapplying the adhesive may regain the dentin adhesion when contamination occurs before light curing. Alternatively, rinsing and drying contaminants followed by adhesive re-application may be effective depending on adhesive type.

Clinical performance of a combined approach for the esthetic management of fluorosed teeth: Three-year results

Objective: The long-term clinical performance of combined therapy including enamel microabrasion and vital bleaching is debatable due to the abrasion of outer enamel surface. The aim of this longitudinal cohort study was to evaluate the 3-year clinical performance of enamel microabrasion in combination with vital tooth bleaching for the esthetic management of fluorosed teeth. Materials and Methods: Fifteen patients with 176 fluorosed incisors and canines were included in this study. All the teeth were treated with enamel microabrasion (Opalustre, Ultradent), and at-home bleaching technique (10% Opalescence PF, Ultradent). Fluorosed teeth were evaluated at baseline, after microabrasion, after combined therapy, and at 3-year follow-up in terms of esthetic criteria (esthetic appearance, brown stains, and opaque white areas), side effects, and patient satisfaction using visual analog scales. The data were statistically analyzed (α = 0.05). Results: Fluorosed teeth revealed significantly better esthetic appearance after microabrasion and combined therapy and at 3-year follow-up compared to those at baseline (P < 0.05). There was a significant relapse in the esthetic appearance and brown stains at 3-year follow-up (P < 0.05). Conclusions: The combined therapy was effective in the esthetic management of fluorosed teeth. However, a significant relapse was observed in the esthetic appearance and brown stains of these patients after 3 years, which also reduced patient satisfaction.