The effect of chlorhexidine gluconate as an endodontic irrigant on the apical seal: long-term results

The purpose of this study was to determine whether chlorhexidine gluconate (0.12%), used as an endodontic irrigating solution, would affect the apical seal of three root canal cements. One hundred, extracted, human, single-canal teeth were divided into 9 experimental groups of 10 teeth each, in addition to a positive and negative control group of 5 teeth each. The teeth were decoronated at the level of the CEJ, accessed, instrumented to a Master apical file #50, irrigated with either sterile saline, 5.25% NaOCl, or 0.12% chlorhexidine gluconate, and dried using paper points. Obturation was accomplished using lateral condensation and one of three endodontic sealers: Roth's 811, AH 26, or Sealapex. Postobturation apical leakage was measured at 270- and 360-day observation periods using the fluid filtration method. Using the mixed-model repeated-measures ANOVA test with Tukey's honest significance difference multiple comparison procedure, the results showed the saline-Sealapex combination had significantly more leakage (p < 0.05) than either the Peridex-Sealapex or saline-Roth's combinations at 270 days. No other significant differences were noted between any sealer-irrigant combination at 270 days. The saline-Sealapex combination had significantly more leakage than the saline-Roth's combination at 360 days. No other significant differences were noted at 360 days. Under the conditions of this study, chlorhexidine gluconate irrigant did not adversely affect the apical seal of three root canal cements at 270 and 360 days.     

The interleukin-1 polymorphism,smoking, and the risk of periodontal disease in the population-based SHIP study

Several studies have shown a role for interleukin-1 gene cluster polymorphisms in the risk assessment for periodontal diseases. In the Study of Health in Pomerania (SHIP), 3148 subjects were randomly selected from the population and assessed for a broad range of diseases and environmental/behavioral risk factors. From the complete study group in the age 40 to 60 years, N = 1085 subjects were genotyped for the interleukin-1 genotype composite polymorphism in relation to periodontal parameters. The study objective was to elucidate the gene-environment interaction between the risk factors smoking and IL-1 polymorphism. An increased risk of periodontal disease was found for IL-1 genotype-positive smokers: odds ratio adjusted for age, sex, education, and plaque OR = 2.50 (95% C.I. 1.21 to 5.13; p = 0.013). This was not the case with subjects who never smoked: OR = 1.09 (0.73-1.62; p = 0.676). These results support the hypothesis of gene-environmental interaction in periodontitis.     

Smoking as a risk indicator for periodontal disease in the middle-aged Vietnamese population

BACKGROUND: Studies from developed countries have found smoking a significant risk indicator for periodontitis. However, few such studies have been conducted in developing populations, where the natural history of the disease is rarely confounded by treatment and smoking is highly prevalent. AIM: The present study aimed to confirm the consistency, strength and dose-response of the association of smoking with periodontitis measured by loss of attachment (LOA) in a representative middle-aged adult sample from a developing country. METHODS: A cross-sectional study with a multistage stratified random sample was conducted in two provinces of Vietnam. RESULTS: A total of 575 (response: 84.6%) 35-44-year-old subjects were interviewed and periodontally examined. Data were re-weighted to represent the population of the provinces. 28.9% were current smokers (CS), 8.6% former smokers (FS) and 62.5% never-smokers (NS). Number of cigarette pack-years was calculated to divide CS into light smokers, LS < or = 5 pack-years, and heavy smokers, HS 5+ pack-years. The US NIDR protocol was employed for LOA measurement at two sites per tooth for every tooth. HS presented with the highest prevalence of LOA exceeding various thresholds followed by LS (chi2, P < 0.001). The extent of sites with LOA > or = 4 mm and LOA > or = 6 mm was significantly higher among HS and LS compared to NS (ANOVA; P < 0.001). The severity scores of LOA for NS, FS, LS and HS were 2.42, 2.50, 2.64 and 3.05 mm respectively (ANOVA; P < 0.001). Disease cases were defined as having 2+ sites with LOA > or = 5 mm and 1+ site with PD > or = 4 mm. Compared to NS, the odds ratio for periodontitis among heavy smokers was 7.17 (CI: 2.87-17.92, P < 0.001). CONCLUSION: Smoking is a risk indicator for periodontitis among the middle-aged Vietnamese population. To pursue a population prevention approach for periodontitis, dentistry in Vietnam needs to be part of antismoking and smoking cessation programs.     

Adhesive analysis of voids in Class II composite resin restorations at the axial and gingival cavity walls restored under in vivo versus in vitro conditions.

OBJECTIVES: Adhesive analysis, under the scanning electron microscope of microtensile specimens that failed through the adhesive interface, was conducted to evaluate the amount of voids present at the axial versus gingival cavity walls of class II composite restorations restored under in vivo and in vitro conditions. METHODS: Five patients received class II resin composite restorations, under in vivo and in vitro conditions. A total of 14 premolar teeth yielded 59 (n=59) microtensile adhesive specimens that fractured through the adhesive interface. The fractured surfaces of all specimens were examined and the % area of voids was measured. RESULTS: Voids at the adhesive joint were highly predictive of bond strengths. An increase in the number of voids resulted in a decrease in the microtensile bond strength. The area of voids at the adhesive interface was as follows: in vivo axial 13.6+/-25.6% (n=12); in vivo gingival 48.8+/-29.2% (n=12); in vitro axial 0.0+/-0.0% (n=19) and in vitro gingival 11.7+/-17.6% (n=16). SIGNIFICANCE: Composite resin may bond differently to dentin depending upon the amount of voids and the cavity wall involved. The bond to the gingival wall was not as reliable as the bond to the axial wall. An increase in the amount of surface voids was a major factor for reducing microtensile bond strengths of adhesive to dentin.     

Comparison of exposed dentinal surfaces resulting from abrasion and erosion

The aim of this study was to compare the shape of exposed dentinal surfaces caused by abrasion and erosion with a view to developing a diagnostic clinical test. The study material consisted of 80 natural teeth and 129 dental models obtained from Australian Aborigines known to display considerable dental abrasion due to their diet, and dental models of 37 Caucasians diagnosed with dental erosion through detailed history and dietary analysis. Polyvinyl siloxane impressions were obtained of all occlusal surfaces with dentinal scooping in both the ‘abrasion’ and ‘erosion’ groups. All impressions were sectioned buccolingually through the deepest point of the scooped dentine, and then the profiles were photocopied at X 2 magnification. The breadth and depth of dentinal profiles were measured to an accuracy of 0.1 mm, enabling ratios of depth:breadth to be determined, and the position of the deepest part of each scooped surface was recorded. The mean depth:breadth ratio of scooped dentine was significantly greater in the Aboriginal natural teeth (0. 19±60.06, mean±SE) than in the Aboriginal dental models (0.15±0.04). Both Aboriginal natural teeth and models with abrasion showed significantly smaller ratios (p<0.05) than the Caucasian models showing erosion (0.33±.07). Furthermore, in the abrasion samples, the deepest region of the scooped dentine tended to be lingually placed more often in maxillary teeth but buccally placed more often in mandibular teeth (p<0.05). These results indicate that scooped dentine on abraded occlusal surfaces of teeth displays significant differences in shape compared with that caused mainly by erosion.     

Potential side effects of dental amalgam restorations

The aim of this study was to explore a possible association between health status and self-reported adverse effects related to dental amalgam restorations. A group of 50 consecutive patients (index group), referred for complaints self-related to dental amalgam restorations, was compared with a control group of individuals matched by age, sex and postal zip code. The patients underwent an oral, stomatognathic, medical and clinical chemistry examination. Mercury levels were examined in blood, urine and hair. The results revealed that somatic diseases were more common in the index group (38% versus 6%). Symptoms related to cranio-mandibular dysfunction were reported by 74% of the patients in the index group versus 24% in the control group, and were diagnosed in 62% and 36%, respectively. The oral health status and the number of amalgam surfaces were similar in the 2 groups. No positive skin patch test to mercury was found in any of the groups. The estimated mercury intake from fish consumption, occupational exposure, and mercury levels in blood and urine were also similar and far below levels, where negative health effects would be expected. The correlation between the number of amalgam surfaces and mercury levels in plasma and urine ( r = 0.43) indicated a release of mercury from dental amalgam restorations in both groups. Since the mercury levels were similar among index patients and controls, mercury was not a likely cause of the impaired health reported by the patients.     

Antibiotic prophylaxis in intraoral orthognathic surgery

A prospective randomized double-blind study was conducted to evaluate two prophylactic antibiotic regimens in a population of 40 patients undergoing intraoral orthognathic surgery. All patients received one intramuscular dose of 600,000 units procaine penicillin G and 400,000 units aqueous penicillin G preoperatively. Two million units aqueous penicillin G were administered intravenously every three hours intraoperatively and postoperatively three hours after the last intraoperative dose. One group of 20 patients then received 2 million units aqueous penicillin G intravenously every four hours for a total of 12 doses (two days) postoperatively. The second group of 20 patients received a placebo intravenously every four hours for a total of 12 doses (two days) postoperatively. Three infections occurred in the group of patients receiving the placebo postoperatively and none in the group of patients receiving the antibiotics postoperatively.