Ümit Candan

Inhibition of Cultivable Bacteria by Chlorhexidine Treatment of Dentin Lesions Treated with the ART Technique

The aim of this study was to examine the changes in the cultivable microflora of carious dentin before and after atraumatic restorative treatment (ART) and investigate the inhibitory effect of chlorhexidine-gluconate-based cavity disinfectant in the microflora. Using a split mouth design, 35 primary molar pairs with class II carious lesions in 35 patients (mean age 7.31 ± 0.47 years) were selected. The total viable counts (TVC), Streptococcus mutans and lactobacilli were first measured in the center of the infected demineralized lesion and then from the hard dentine after caries removal by the ART technique. Chlorhexidine-gluconate (2%)-based cavity disinfectant was applied to one of the molar pairs and the other molar received no disinfectant treatment. Thereafter, all of the teeth were restored with glass ionomer cement (GIC). Cavities were reassessed after 6 months and again dentine samples were microbiologically investigated. Removal of carious dentine by ART significantly reduced TVC, S. mutans and lactobacilli. After 6 months, application of chlorhexidine exhibited a greater significant reduction in TVC (p = 0.013), and a significant reduction in S. mutans compared to the nondisinfected group (p < 0.001). A significant reduction in lactobacilli counts was observed in both groups after 6 months, but the difference between the disinfected and nondisinfected groups was not significant (p = 0.056). ART was found to be effective in reducing the cultivable microflora and chlorhexidine-gluconate-based cavity disinfectant might serve as a suitable additional agent in inhibiting the residual bacteria in the dentine.

Effects of Glass Fiber Layering on the Flexural Strength of Microfill and Hybrid Composites

STATEMENT OF THE PROBLEM In stress-bearing cavities, low fracture resistance adversely affects the longevity of the dental resin composite restorations. PURPOSE The aim of this in vitro study was to investigate the effect of glass fiber layering on the flexural strength of microfill and hybrid composites. MATERIALS AND METHODS Flexural test specimens (N = 75) were prepared according to International Organization for Standardization (ISO) 4049 specifications (25 x 2 x 2 mm) by using a standard metallic mold. Materials used and groups were as follows (N = 15): group 1: hybrid composite (Clearfil APX, Kuraray Co.Ltd, Osaka, Japan); group 2: microfill composite (Clearfil ST, Kuraray Co.Ltd.); group 3: hybrid + microfill composite; group 4: woven glass fiber (EverstickNet, StickTech Ltd, Turku, Finland) + hybrid composite; group 5: woven glass fiber + microfill composite. The specimens were stored in distilled water at 37 degrees C for 7 days. Afterward, they were loaded to fracture (1 mm/min) by using a universal testing machine (AG-50 kNG Shimadzu Co., Kyoto, Japan). Flexural strengths were expressed as maximum flexural load per cross-sectional area of the specimen. The results were statistically analyzed with Kruskall-Wallis and Mann-Whitney U tests (p < 0.01). RESULTS Significant increases in the flexural strength were found for both hybrid and microfill composites when fiber layering was used (group 1: 78 +/- 7 MPa; group 4: 93 +/- 4 MPa) (group 2: 42 +/- 5 MPa; group 5: 64 +/- 4 MPa) (p < 0.01). Flexural strength of fiber-reinforced hybrid composite was significantly higher than the other groups evaluated (p < 0.01). There were no significant differences in flexural strength between microfill/hybrid combination and fiber-reinforced microfill composite (p > 0.01). CONCLUSIONS Glass fiber layering of microfill and hybrid composites presented higher flexural strength, and veneering of hybrid composite with microfill composite increased the resistance of the restoration.

Effect of 2% chlorhexidine gluconate cavity disinfectant on microtensile bond strength of tooth-coloured restorative materials to sound and caries-affected dentin

This study evaluated the effect of 2% chlorhexidine gluconate-based cavity disinfectant (CHX) on the microtensile bond strength (μTBS) of glass ionomer, resin-modified glass ionomer and packable resin composite to sound and caries-affected dentin. Sound and occlusal caries-affected human third molars (N = 36, n = 3 per group) were randomly divided into three experimental groups to receive one of the following restorative materials. (a) Glass ionomer (Ketac Molar, 3 M ESPE; GI), (b) resin-modified glass ionomer (Vitremer, 3 M ESPE; RMGI) and (c) packable resin composite (Surefil, Dentsply; PRC) with a bonding agent (Prime Bond NT, Dentsply De Trey). Caries was removed using a caries-detecting dye (Caries Detector, Kuraray Medical Ltd.) and flat dentin surfaces were achieved by finishing up to 1200-grit silicon carbide abrasive. Half of the teeth in each group received 2% CHX (Consepsis, Ultradent). Dentin surfaces were built-up with the respective materials incrementally and were sectioned with a slow-speed saw into multiple beams. The beams were subjected to μTBS test (0.5 mm/min) in a Universal Testing Machine. The data were analysed using two-way analysis of variance and Tukey’s tests. For each restorative material, μTBS results were not affected by the application of CHX (p > 0.05) on both sound and caries-affected dentin (p > 0.05). PRC in combination with the corresponding bonding agent showed significantly higher results (p < 0.05) than those of GI and RMGI, on sound and caries-affected teeth, respectively. Cohesive failure in dentin was not observed in any of the groups. The use of 2% chlorhexidine-based cavity disinfectant did not impair the adhesion of the restorative materials tested to either sound or caries-affected dentin.

Efficacy of Metapex in Root Canal Treatment of Primary Teeth

OBJECTIVE: The aim of this study was to evaluate clinically and radiographically the efficacy of Metapex as root canal filling material in primary molars. METHODS: 50 primary molars in two groups of children aged 3-9 years were obturated with Metapex and were postoperatively followed-up clinically and radiographically for periods of 3 and 6 months. RESULTS: The clinical and radiological findings were in accordance with each other. The overall success rate was 100% for the group of 3-month follow-up and 98% for the 6-month follow-up-group. CONCLUSION: Metapex showed a favorable success rate and can be used safely as root canal filling in primary teeth.

Evalution of Occupation Related Health Complaints in a Dental Education Hospital

Objectives: This study aims to find a relationship of profession related health complaints by identifying these complaints and this complaints’ relationship with age, gender, completed years in the profession, the mode of operation in a health complex. Methods: In İzmir Dental Education Hospital, a form including gender, marital status, their working period as they started their profession and their occupation related health complaints filled by interviewing face to face. In the evaluation of the data, T-test, Chi-Square and Mann-Whitney-U test were used. Results: In this study, 324 people from 21-61 years of age(39.88±9.003) took place, 38.3%were male, and 61.7% were women. 186(52.4%) people were health professionals; 79 dentists, 24 nurses, 79 technicians, 4laboratorian. 138(42.6%) people werenot health professionals; 75 officers, 62 were employees. When compared to non-health professionals, health professionals were found to have more back, waist, neck, shoulder and headache problems in which the difference was statistically significant(p=0.001). In nurses and dentists; back, waist, neck and shoulder pains were observed at a higher rate than other professionals. When working duration of employment (in years) and back, waist, neck, and headache problems compared; between non-health workers and health professionals statistically significant difference was determined (p=0.000). Conclusion: Dentists and nurses are having more career-related health problems.

FİBERLE GÜÇLENDİRMENİN NANOFİL KOMPOZİTİN EĞME DİRENCİNE ETKİSİNİN İNCELENMESİ

Aim: The purpose of this in vitro study was to investigate the effect of woven glass fiber layering on flexural strength of nanofil composite resin. Material and Method: Sixty specimens were prepared standard metallic mold (25x2x2 mm) prepared according to ISO 4049 for flexural strength. The specimens were divided into four groups (n: 15) as follows; Flowable (Filtek Flow) + nanofil composite (Filtek Supreme) (Gr I), nanofil composite (Gr II), Flowable +woven glass fiber (EverStick Net) + nanofil composite (Gr III), woven glass fiber + nanofil composite (Gr IV).The specimens were stored in distilled water at 370 C for 24 hour, thenevaluated with three-point bending test using Universal Testing Machine. Data were analysed using Kruskall Wallis and Mann Whitney U tests. Three samples from each group were examined by SEM. Result:The mean flexural strength values of the groups I, II, III and IV were 93.6±4, 85.5±6, 107±9 and 101±5 respectively. Glass fiber-reinforced nanofil composite applied with flowable composite (Gr III) exhibited higher flexural strength values in comparison to the other groups (p<0.05 While control group (Gr II) exhibited the lowest). Significant differences were found between flexural strength of control and the other groups (p<0.05). In SEM evaluation, it was detected that in fiber-reinforced groups (Groups III and IV) fractured area was limited by the fiber in the stressed region. Conclusion: Within the limitations of this in vitro study it is concluded that glass fiber reinforcement improves the flexural strength of the nanofill composite. In SEM evaluation after fracturing, glassfiber reinforcement prevented crack propagation. Key Words: Composite resin, fiberreinforcement, flexural strength, scanning electron microscope