Cemal Eronat

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.

PCR-based identification of selected pathogens associated with endodontic infections in deciduous and permanent teeth.

OBJECTIVE The aim of the present study was to evaluate the presence of the selected pathogens in samples from deciduous and permanent tooth root canals by using PCR method and to determine the association of these organisms with clinical symptoms. STUDY DESIGN A total of 145 children, 5 to 13 years old, were involved in this study. The presence of selected pathogens (Actinomyces israelii, Candida albicans, Enterococcus faecalis, Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus intermedius, Treponema denticola, Parvimonas micra, Tannerella forsythensis, Enterococcus faecium, Prevotella melaninogenica) in infected root canals was studied using PCR. RESULTS T. denticola (P = .012, .02) and E. faecalis (P = .012, .04) were highly associated with periapical radiolucency and previous pain, while P. gingivalis was associated with tenderness to percussion in both deciduous and permanent teeth (P = .01, .015). CONCLUSION The results of the present study confirm that certain species of microorganisms are associated with clinical signs and symptoms of endodontic disease in both deciduous and permanent teeth.

Staining patterns in teeth discolored by endodontic sealers.

The use of endodontic materials may lead to internal discoloration of teeth. In view of prevention of and therapy for tooth discoloration, the staining patterns inside discolored teeth were investigated in vitro. Extracted premolars were discolored using the following endodontic sealers: Grossmans cement, zinc oxide-eugenol, Diaket, Tubli-Seal, AH26, Endomethasone, N2, and Rieblers paste. The sealers were introduced into the pulp cavities and the color of the external buccal tooth surfaces was determined before and 7 wk after introduction of the sealers. All materials produced measurable coronal discoloration. The discolored tooth crowns were hemisectioned and internal staining patterns were studied. For all teeth, the dentin was found to be partly to entirely stained. No discoloration could be observed in the enamed. For each material the internal staining patterns were in agreement with the discolorations observed on the external surfaces.

The Role of Vitamin D Receptor Polymorphisms on Dental Caries.

OBJECTIVE To determine the association between the ApaI, FokI, Cdx2 and TaqI polymorphisms of vitamin D receptor (VDR) gene in caries-active (high-moderate) and caries-free children. STUDY DESIGN A hundred and fifty children (75 males, 75 females, mean age: 10.19 ± 1.61 years) were included in the study. The subjects were divided into three groups as high caries risk group (DMFT, dft>4)(n=55), moderate caries risk group (DMFT, dft=1-4)(n=57) and caries-free group (n=38). From each individual, blood samples were collected and DNA was extracted. The VDR gene was genotyped for the polymorphisms ApaI, FokI, Cdx2 and TaqI using polymerase chain reaction and restriction fragment length polymorphism methods. All data were analyzed by chi-square test, Fishers exact test and t test. RESULTS There was statistically significant difference in the frequency of TaqI genotypes (tt) between caries-active and caries-free children (p=0.029). No statistically significant differences were detected between ApaI, FokI, Cdx2 genotypes and dental caries. CONCLUSION In the future, VDR gene polymorphisms may be used as a marker for the identification of patients with high caries risk.

Comparative evaluation of pro-inflammatory cytokine levels in pulpotomized primary molars.

The present in vivo study was performed to investigate the levels of the pro-inflammatory cytokines, interleukin (IL)-1α, IL-6, and IL-8, in primary molars for which pulpotomy was clinically indicated, and to evaluate the success rates of three different pulpotomy agents employed for cariously (CExp) or mechanically exposed (MExp) primary molars. Forty-seven primary molars were classified as MExp or CExp according to the type of pulpal exposure. Pulp tissue was harvested and analyzed using enzyme-linked immunosorbent assay (ELISA). Subsequently, three pulpotomy agents-calcium hydroxide (CH), mineral trioxide aggregate (MTA), and formocresol (FC)-were applied randomly, and the outcome was observed radiographically for 18 months. Levels of IL-6 and IL-8 were significantly higher in CExp pulp than in MExp pulp (P < 0.05). In the CH pulpotomy group, MExp teeth showed a higher success rate than CExp teeth. There was no significant difference in success rate between MExp and CExp teeth in both the FC and MTA groups. The levels of IL-6 and IL-8 have the potential to become indicators of pulp status and can be monitored by researchers to make the prognosis of vital pulp therapies less uncertain. As MTA and FC yielded higher rates of success than CH in CExp teeth, the choice of pulpotomy agent appears to be important in this context.

Associations of interleukin (IL)-1β, IL-1 receptor antagonist, and IL-10 with dental caries

Streptococcus mutans is important in dental caries. Although the role of cytokines in the pathogenesis of dental caries is not clear, components of S. mutans were found to stimulate production of pro-inflammatory cytokines. We examined the associations of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), and IL-10 with dental caries. Unstimulated whole saliva and blood samples were obtained from 108 children aged 6-12 years with high caries (decayed, missing, or filled teeth [dmft/DMFT] index >4, n = 37), moderate caries (dmft/DMFT = 1-4, n = 37), or caries-free (dmft/DMFT = 0, n = 34). S. mutans level was classified as low (<10(5) colony-forming units [CFU]/mL) or high (≥10(5) CFU/mL). Saliva and serum concentrations of IL-1β, IL-1ra, and IL-10 were determined by ELISA. IL-1β, IL-1ra, and IL-10 gene polymorphisms were genotyped using PCR and restriction fragment length polymorphism analysis. The chi-square, Mann-Whitney U, one-way ANOVA, posthoc, Fishers exact, and t tests were used in statistical analysis. Dental caries was not correlated with salivary or serum concentrations of the studied cytokines. S. mutans level positively correlated with saliva IL-1β concentration and inversely correlated with saliva IL-1ra concentration. There was no correlation of IL-1β, IL-1ra, or IL-10 gene polymorphisms with dental caries. S. mutans is important in stimulating saliva IL-1β and inhibiting IL-1ra. Future studies of associations between cytokines and dental caries should investigate additional cytokines and enroll a larger number of participants.

Effects of 2,4-dichlorophenoxy acetic acid dimethyl amine salt on dental hard tissue formation in rats ☆

2,4-Dichlorophenoxy acetic acid dimethyl amine salt (2,4-D DMA), as one of the phenoxy acids, is used as a herbicide mainly against broad-leaf weeds in cereal crops, sugar cane, and on turf, pasture, and non-crop land. Some formulations of 2,4-D may be contaminated with dioxins. Recently, it has been shown that chlorinated organic compounds, dioxins, and furans are present in mothers milk and may cause developmental defects in childrens teeth. Therefore, we aimed to evaluate the effects of 2,4-D DMA on odontogenesis in rats. 2,4-D DMA was given orally combined with rat food to pregnant albino rats. Each group consisted of two pregnant rats and, 0 (control, group A), 25 ppm (group B), 50 ppm (group C), and 100 ppm (group D) 2,4-D DMA was given to each pregnant rat as daily intake. 2,4-D DMA affected young rats dental development and dose-related findings were found in experimental groups. The odontoblast layer was irregular and globular dentin formation was present in Groups B, C, and D but not in the control group. Thickness of enamel decreased in Groups C and D. The results of the study have shown that 2,4-D DMA could disturb dental development in rats even in relatively low doses. It is concluded that environmental contaminants such as chlorinated organic pesticides may play an important role in infants dental development when taken via mothers milk.

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.