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, Fisher's 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)-1ß, 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)-1ß, 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-1ß, IL-1ra, and IL-10 were determined by ELISA. IL-1ß, 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, Fisher's 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-1ß concentration and inversely correlated with saliva IL-1ra concentration. There was no correlation of IL-1ß, IL-1ra, or IL-10 gene polymorphisms with dental caries. S. mutans is important in stimulating saliva IL-1ß and inhibiting IL-1ra. Future studies of associations between cytokines and dental caries should investigate additional cytokines and enroll a larger number of participants.

No adverse effect to bonding following caries disinfection with chlorhexidine.

PURPOSE: The purpose of this study was to evaluate the effect of 2% chlorhexidine-based cavity disinfectant on the microtensile bond strength of 3 restorative materials to caries-affected and sound primary dentin. METHODS: Eighteen exfoliated primary molars with occlusal caries and 18 sound primary molars were randomly divided into 3 experimental groups, according to the following restorative materials: (1) high-viscosity glass-ionomer cement (GIC; KetacMolar); (2) resin-modified GIC (Vitremer); and (3) dentin adhesive (Prime&Bond NT) with a packable composite (Surefil). The molars were further divided into 2 subgroups according to the application of chlorhexidine-based cavity disinfectant (Consepsis). Standard restoration blocks of 5 mm high were built up over the treated surfaces. Bond strength results were evaluated using by 1-way analysis of variance, and multiple comparisons were done via Tukey's test (P<.05). RESULTS: No statistically significant differences were found between the high-viscosity and resin-modified GIC and composite showed the highest bond strength values on both dentin surfaces. The distribution of failure modes between the high-viscosity and resin-modified GICs were mostly cohesive where adhesive failures were noted significantly in the composite. CONCLUSION: Using 2% chlorhexidine gluconate did not interfere with the microtensile bond strength of glass ionomer cements and composite.

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.

The effect of a chlorhexidine containing cavity disinfectant on the clinical performance of high-viscosity glass-ionomer cement following ART: 24-month results.

PURPOSE: To evaluate the effect of a chlorhexidine-gluconate-based cavity disinfectant on the clinical performance of high viscosity glass-ionomer cement following the ART approach under field conditions after 24 months. METHODS: 126 school children 6-8 years old who had bilateral matched pairs of carious Class I and II primary molars were included. A split mouth design was used in which Ketac Molar was randomly placed with or without the use of chlorhexidine-gluconate-based cavity disinfectant on contralateral sides by three dentists. The restorations were evaluated after 6, 12 and 24 months by two experienced examiners using USPHS-Ryge criteria. RESULTS: The 24-month mean cumulative survival rates of Ketac Molar without the use of disinfectant were 97.7% and 69.4% while in the disinfectant group, the survival rates were 95.2% and 63.9% in Class I and II restorations, respectively with no significant difference between the groups in both class types. In the non-disinfected group, large Class II cavities had significantly better survival rates than did small Class II cavities (P = 0.023). In the disinfected group, the failure rates in mean cumulative survivals from 6 to 12 months and 12 to 24 months significantly increased with time (P = 0.004 and P = 0.016 respectively).

The correlation between serum immunoglobulin A and immunoglobulin G levels and the presence of Treponema denticola in human periapical lesions.

The aim of this study was to compare the serum immunoglobulin A (IgA) and immunoglobulin G (IgG) levels and the presence of Treponema denticola in the root canals in a group of teeth with/without periapical lesion. A total of 66 children aged 8 to 13 years old were involved in this study. Five milliliters of blood samples were taken to detect the serum IgA and IgG levels. Sixty-six endodontic samplings were also obtained to determine the presence of T. denticola by polymerase chain reaction. The presence of T. denticola between the groups with/without periapical lesion was statistically significant (p = 0.026). A significant negative correlation was found between serum IgG and IgA levels and the presence of T. denticola (p = 0.023 and 0.038, respectively). This study may support the hypothesis that the presence of T. denticola in the root canals is mainly related to the periapical lesions, and the higher levels of serum IgG and IgA levels may protect against T. denticola.

Detection of Enterococcus faecalis in Necrotic Teeth Root Canals by Culture and Polymerase Chain Reaction Methods.

OBJECTIVES: The aim of this study was to investigate the presence of Enterococcus faecalis in endodontic infections in both deciduous and permanent teeth by culture and polymerase chain reaction (PCR) methods. METHODS: A total of 145 children aged 5-13 years old were involved in this study. The presence of E. faecalis in necrotic deciduous and permanent teeth root canals was studied using culture and polymerase chain reaction methods. RESULTS: Among 145 molar teeth, 57% (n=83) presented necrotic asymptomatic pulp tissues and were included in this study. Culture and PCR methods detected the test species in 18 and 22 of 83 teeth involved, respectively. E. faecalis was cultured from 8 (18%) of 45 necrotic deciduous teeth and from 10 (26%) of 38 necrotic permanent teeth. PCR detection identified the target species in 10 (22%) and 12 (32%) of necrotic deciduous and permanent teeth respectively. Statistically significant difference in the presence of E. faecalis in deciduous and permanent teeth was found by culture and PCR methods (P=0.03 and 0.02, respectively). The difference in the presence of E. faecalis between two different methods was not statistically significant (P>.05). CONCLUSIONS: The results of the present study confirm that both culture and PCR methods are sensitive to detect E. faecalis in root canals.

A clinical evaluation of resin-based composite and glass ionomer cement restorations placed in primary teeth using the ART approach: results at 24 months.

BACKGROUND: The authors evaluated the 24-month performance of a packable resin-based composite/dentin bonding system and a high-viscosity glass ionomer cement (GIC) in restorations placed in primary molars with the atraumatic restorative treatment (ART) approach. METHODS: Three dentists placed 419 restorations in 219 children aged 6 through 10 years who had bilateral matched pairs of carious posterior Class I and II primary teeth. They used a split-mouth design to place the two materials, which were assigned randomly to contralateral sides. The authors evaluated the restorations according to U.S. Public Health Service Ryge criteria. RESULTS: After 24 months, 96.7 percent of the Class I GIC restorations and 91 percent of the resin-based composite restorations survived, while the success rates for the Class II restorations were 76.1 percent and 82 percent for the GIC and resin-based composite restorations, respectively. The survival rate of the Class II resin-based composite restorations was 5.9 percent higher than that of the GIC restorations at the 24-month evaluation, but this difference was not statistically significant. However, the study results showed a statistically significant difference in survival rates between Class I and II restorations for both materials. CONCLUSION AND CLINICAL IMPLICATIONS: The two-year clinical performance of both materials was satisfactory for the restoration of Class I and II primary molars using the ART approach.

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.

Effect of Carisolv on the human dental pulp: a histological study.

OBJECTIVES: The aim of this study was to investigate histopathologically after 1 week and 1 month the effect of Carisolv on exposed human pulp after a contact period of 10 min in comparison to sterile saline solution. METHODS: Class V cavities were prepared in 40 human first premolars, and the pulp chambers were perforated. The pulp tissue was either exposed to Carisolv or sterile saline solution for 10 min, covered with Teflon and restored with compomer filling material. After observation periods of 1 week and 1 month, the teeth were extracted and examined by light microscopy. RESULTS: Histological evaluation revealed similar pulpal response which consisted of a slight inflammation in both groups after 1 week. The only difference was localized haemorrhage in controls while no haemorrhage was observed in the test group which may show the haemostatic effect of Carisolv. After 1 month the test teeth displayed a very mild inflammation adjacent to the perforation area while haemorrhage disappeared in the controls. In general, pulps showed structural integrity in both groups. Statistical analysis showed no difference between the test and the control groups in both test periods. CONCLUSIONS: The results suggest that Carisolv is biocompatible with human pulp tissue and may have a haemostatic effect.

A comparative study of plaque mutans streptococci levels in children receiving glass ionomer cement and amalgam restorations.

PURPOSE: The restorative materials amalgam (Standalloy F) and glass ionomer cements (Chelon Silver) were comparatively investigated to determine the number of mutans streptococci METHODS: Saliva and plaque were collected from patients before and 40 days after the insertion of their restorations. RESULTS: Total bateria and mutans streptococci counts were found to be statistically significantly reduced when compared with the prerestoration counts in the saliva samples (P<0.001). Microbiological analysis of the dental plaque showed that the number of mutans streptococci in the glass ionomer cements was significantly lower than in the amalgam restorations (P<0.001). CONCLUSIONS: This study showed that silver glass ionomer cements inhibited the growth of mutans streptococci.

Histological investigation of physiologically resorbing primary teeth using Ag-NOR staining method.

OBJECTIVE: The aim of this study was to investigate pulpal tissue of primary teeth in early and late stages of physiological resorption by means of silver-binding nucleolar organizer region (Ag-NOR) staining. STUDY DESIGN: Ten primary teeth in early, ten in the late stage of resorption and five sound premolar teeth pulps as the control group were investigated by means of silver-binding nucleolar organizer region (Ag-NOR) staining. RESULTS: The mean number of Ag-NOR's per nucleus increased with the continuing of the resorption process. The difference in the mean number of Ag-NORs was statistically significant both in the early and late stage of resorption compared with controls (P > 0.001). In the early stage of resorption calcific plates in the apical part of the pulps were observed. Odontoclasts, as well as inflammatory cells, were observed in the late stages of resorption. CONCLUSIONS: The increase in the mean number of Ag-NORs per nucleus with the progression of the resorption process in primary teeth suggests that metabolic cell activity in the early stages of resorption is enhanced and increased with the continuing of the process, thus showing the importance of the pulp tissue in the resorption process.