Effectiveness of fissure sealant retention and caries prevention with and without primer and bond.

OBJECTIVE: This study evaluated the effectiveness of sealant retention and caries prevention with and without primer and bond below the fissure sealant among Kuwaiti schoolchildren. SUBJECTS AND METHODS: This clinical trial used fissure sealant that was applied to four sound first permanent molars on 78 children. All the teeth were cleaned with pumice and rubber cups, isolated with rubber dams, and etched for 20 s. In a split-mouth study design, for the test teeth (n = 156), primer and bond (3M Scotchbond Multi-Purpose Plus System primer and bond) were applied below the sealant, and for the control teeth (n = 156), only sealant (Delton Plus) was applied. The number of tooth surfaces included was 480. Due to loss to follow-up, only 60 children were evaluated at 5 years for sealant retention and caries. The evaluation criteria were: completely retained sealant, complete or partial sealant retention, and caries. RESULTS: In teeth sealed with primer and bond, 47 (19.6%) tooth surfaces had completely retained sealant, 60 (9.2%) teeth had partially retained sealant, while in 51 (21.3%) caries was prevented and 120 (50%) tooth surfaces were carious or filled. In teeth sealed without primer and bond, 25% (60 tooth surfaces) had completely retained sealant, 6% (14 teeth surfaces) had partially retained sealant, 26% (54 teeth surfaces) showed caries prevention, and 49.6% (119 tooth surfaces) were carious or filled. There was no difference between teeth sealed with primer and bond (120 teeth) and teeth sealed without primer and bond (120 teeth) in completely retained sealant (p = 0.15), complete or partial sealant retention (p = 0.6), caries prevented (p = 0.37), and caries (p = 0.93). CONCLUSION: Caries prevention was not enhanced in teeth sealed with primer and bond sealant compared with those sealed with sealant alone.

Distribution and excretion of BisGMA in guinea pigs.

Bisphenol-A-glycidyldimethacrylate (BisGMA) is used in many resin-based dental materials. It was shown in vitro that BisGMA was released into the adjacent biophase from such materials during the first days after placement. In this study, the uptake, distribution, and excretion of [(14)C]BisGMA applied via gastric and intravenous administration (at dose levels well above those encountered in dental care) were examined in vivo in guinea pigs to test the hypothesis that BisGMA reaches cytotoxic levels in mammalian tissues. [(14)C]BisGMA was taken up rapidly from the stomach and intestine after gastric administration and was widely distributed in the body following administration by each route. Most [(14)C] was excreted within one day as (14)CO(2). The peak equivalent BisGMA levels in guinea pig tissues examined were at least 1000-fold less than known toxic levels. The peak urine level in guinea pigs that received well in excess of the body-weight-adjusted dose expected in humans was also below known toxic levels. The study therefore did not support the hypothesis.

Is there a risk of harm or toxicity in the placement of pit and fissure sealant materials? A systematic review.

BACKGROUND: Recently, there has been increased interest in the in vivo release of dental sealant components, such as bisphenol A (BPA), which has the potential to bind the estrogen receptors of relevant cells at subtoxic concentrations in vitro, impairing the development, health and reproductive systems of wildlife. The purpose of this systematic review was to investigate whether the placement of pit and fissure sealant materials causes toxicity, and thus harms patients. METHODS: The literature search (from the earliest record up to March 2007) for relevant articles was done with Ovid MEDLINE, CINAHL and other bibliographic databases. RESULTS: A total of 377 articles were identified by the literature search; relevance was determined by examining the title and abstract of the articles. Eleven original studies met the inclusion criteria. These articles were read in full and scored independently by 2 reviewers. RECOMMENDATIONS: The evidence suggests that patients are not at risk for exposure to BPA from the use of dental sealants. To reduce the potential, if any, for BPA toxicity from sealants, dental providers should use a mild abrasive, such as pumice, either on a cotton applicator or in a prophy cup; have older children and adolescents gargle with tepid water for 30 seconds; or wash the sealant surface for 30 seconds with an air-water syringe while suctioning fluids and debris from a child"s mouth.

In vivo effects of BISGMA-a component of dental composite-on male mouse reproduction and fertility.

The aim of this study is to investigate the effects of the resin monomer bisphenol A glycerolate dimethacrylate (BISGMA) on adult male mouse fertility. Male Swiss mice were administered various concentrations of BISGMA (0, 25, and 100 microg/kg) for a period of 28 days, and the effects on fertility was assessed by breeding these males with untreated female mice after the exposure periods. The results showed that fertility was significantly reduced when male mice were exposed to BISGMA, in comparison with their control counterparts. In females mated with males exposed to BISGMA, there was a significant reduction in the pregnancy rates as well as the number of viable fetuses. The number of resorptions out of the total number of implantations was significantly increased in females mated with males that had been exposed to BISGMA. Furthermore, the number of females with resorptions was also significantly increased. Significant reductions in bodyweight and weights of the testis and preputial glands were also observed. The weights of the seminal vesicles were significantly increased in males exposed to BISGMA in comparison with their control counterparts. There were significant reductions in testicular sperm counts, epididymal sperm counts and in the efficiency of sperm production. In conclusion, exposure of male mice to BISGMA results in an impairment of the reproductive system and fertility.

Effect of double-application of all-in-one adhesives on dentin bonding.

OBJECTIVES: To evaluate the effect of double-application of all-in-one adhesives using the micro-shear bond test. METHODS: The occlusal surfaces of extracted human third molars were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. Three commercially available and one experimental bonding system were used in this study: Adper Prompt L-Pop (APL, 3M ESPE), REACTMER BOND (RB, Shofu), XENO III (Xeno, Dentsply-Sankin) and newly developed OBF-2 (OB2, Tokuyama Dental). These adhesives were applied on the dentin surfaces by either the manufacturers' instructions or by an experimental method (single-application or double-application). Resin composite was then placed and light-cured for 40s. After 24h immersion in water, a micro-shear bond test was carried out and the fractured dentin surfaces were observed microscopically. The data were analyzed by one-way ANOVA and Tukey's HSD tests (p<0.05). RESULTS: The mean bond strengths of APL, RB, Xeno and OB2 with single-application were 22.7, 28.3, 30.3 and 34.6MPa, respectively. The mean bond strengths of APL, RB, Xeno and OB2 with double-application were 29.5, 27.2, 29.6 and 32.5MPa, respectively. There were no statistically significant differences in micro-shear bond strengths between the single- and double-application methods for each adhesive system (p>0.05). The morphological observation of the fractured dentin surfaces revealed differences between the single- and double-application groups especially for APL and OB2. CONCLUSIONS: Micro-shear bond strengths of all-in-one adhesives in this study showed no statistically significant differences between the single-application and the double-application method.

The influence of dft index on sealant success: a 48-month survival analysis.

Early loss of pit and fissure sealants is considered to be primarily dependent on inadequate isolation of the tooth from salivary contamination during application. Gradual additional loss is considered to be caused by occlusal wear, shearing forces, and marginal failure. Our hypothesis is that the caries risk of the child may be an additional factor in sealant loss. The objective of this study was to analyze the influence of caries history in primary teeth (dft index) on the success of sealants. Delton light-polymerized sealant was applied in 104 six- to eight-year-old children, followed for four years on a six-month-visit basis. All sound permanent first molars were sealed during the study. A survival analysis was used to describe sealant success over time. A Cox proportional hazards regression model was built to test the influence on sealant success of the dft index and site of sealant application (mandibular occlusal surface, maxillary fossae, and maxillary distolingual fissure), controlling for some potential confounders. Sealant half-life was 46 months. Site and dft index were related to sealant survival. The maxillary fossae showed the best retention, followed by the mandibular occlusal site and the maxillary disto-lingual fissure. The higher the dft, the higher the risk of sealant failure. This study has implications for sealant study designs and public sealant programs.

Effectiveness of visible light fissure sealant (Delton) versus fluoride varnish (Duraphat): 24-month clinical trial.

The present study compares visible-light Delton with Duraphat fluoride varnish for the prevention of occlusal caries in permanent first molars. A clinical trial was carried out in three groups of 6-8-yr-old schoolchildren: a sealant group (100 children), in which Delton light-polymerized fissure sealant was applied to permanent first molars; a varnish group (98 children), in which Duraphat was applied to permanent first molars; and a control group (116 children). Replacement (sealant) and reapplication (varnish) was carried out every 6 months. Percent effectiveness at 24 months (percentage of saving from caries taking molars as analysis unit) for those molars initially healthy and with complete occlusal eruption was analyzed. 272, 252 and 238 molars met the inclusion criteria in the control, varnish and sealant groups, respectively. Of these, 45.2%, 28.2% and 10.5% developed caries after 24 months. The effectiveness was greater in the sealed molars than in the varnished molars (62.7%).

A 24-month study comparing sealant and fluoride varnish in caries reduction on different permanent first molar surfaces.

OBJECTIVE: The aim of this study was to determine the separate effects of dental sealants and fluoride varnish on dental caries in fissured and nonfissured surfaces of permanent first molars. METHODS: A clinical trial was conducted with three groups of 6- to 8-year-old schoolchildren: a sealant group (n = 100), in which Delton was applied to first molars; a varnish group (n = 98), in which Duraphat was applied to first molars; and a control group (n = 116), which had no intervention as part of the study. Absolute and percent caries reductions were compared at 24 months. RESULTS: Compared to the controls, sealants resulted in a 68 percent and 87 percent reduction on fissured and nonfissured surfaces, respectively. The corresponding figures for varnish were 38 percent and 66 percent. CONCLUSION: Sealant and fluoride varnish are effective in preventing caries in both fissured and nonfissured surface.

Clinical performance of one-step self-etch adhesives applied actively in cervical lesions: 24-month clinical trial.

OBJECTIVES: To evaluate the clinical performance of two one-step self-etch adhesives in noncarious cervical lesions (NCCL) under active or passive application mode. METHODS: Thirty-one patients with four NCCL were enrolled in this study. One hundred and twenty-four restorations were placed according to one of the following conditions: 1) Adper Prompt L-Pop (AP), active application (APA); 2) AP, passive application (APP); 3) Xeno III (XE), active application (XEA), or 4) XE, passive application (XEP). The restorations were evaluated by the FDI World Dental Federation criteria at baseline and after six, 12, and 24 months of clinical service. The effects of adhesive, mode of application, and recall period were assessed via mixed generalized linear model (α=0.05). RESULTS: The adhesive AP and the passive application mode showed significantly higher marginal staining than did XE and active application, respectively (p<0.05). With regard to the retention rates, the active application mode yielded higher retention rates at the 24-month recall compared to the passive application, regardless of the material. The individual retention rates (95% confidence interval) of both adhesives in the active application mode were the same, 96.8% (83.8-99.4%), while in the passive application rates were 87.1% (71.2-94.9%) and 80.7% (63.7-90.8%) for XE and AP, respectively. CONCLUSIONS: The active application improved the retention rates of both adhesives after 24 months and minimized the marginal staining at enamel margins.

Effect of operator experience on the outcome of fiber post cementation with different resin cements.

OBJECTIVES: To evaluate the influence of operator experience (dentist vs student) and cementation system (Adper Scotchbond Multi-Purpose [SBMP] + RelyX ARC [1]; Adper Single Bond 2 [SB] + RelyX ARC [2] and RelyX U100 [3]) on the push-out bond strength (BS) of fiber post to radicular dentin. MATERIALS AND METHODS: The roots of 48 extracted human maxillary central incisors were prepared and divided into six groups (n=8), according to combination of the above factors. Glass fiber posts were cemented in accordance with the instructions of the manufacturer of each cementation system. After water storage at 37°C for one week, the roots were cross-sectioned into six 1-mm thick slices and the push-out test was performed (0.5 mm/min). Data were statistically analyzed by two-way analysis of variance and Tukey tests (α=0.05). The BS results obtained by dentist and student for each cementation system were compared using the Student t-test (α=0.05). RESULTS: Higher BS means were observed for the expert operators, irrespective of the cementation system used (p=0.006). RelyX U100 showed the highest bond strength, but it did not differ from SBMP + RelyX ARC. The Student t-test revealed that only RelyX U100 was not affected by the operator's experience. CONCLUSION: Within the limitations of this in vitro study, it can be concluded that the self-adhesive cement RelyX U100 showed the highest bond strength to the root canal in the student's group, and its performance was not affected by the operator's experience.

Dental composite restorations and psychosocial function in children.

BACKGROUND AND OBJECTIVE: Resin-based dental materials may intraorally release their chemical components and bisphenol A. The New England Children's Amalgam Trial found that children randomized to amalgam had better psychosocial outcomes than those assigned to composites for posterior tooth restorations. The objective of this study was to examine whether greater exposure to dental composites is associated with psychosocial problems in children. METHODS: Analysis of treatment-level data from the New England Children's Amalgam Trial, a 2-group randomized safety trial comparing amalgam with the treatment plan of bisphenol A-glycidyl methacrylate (bisGMA)-based composite and urethane dimethacrylate-based polyacid-modified composite (compomer), among 534 children aged 6 to 10 years at baseline. Psychosocial function at follow-up (n = 434) was measured by using the self-reported Behavior Assessment System for Children (BASC-SR) and parent-reported Child Behavior Checklist (CBCL). RESULTS: Children with higher cumulative exposure to bisGMA-based composite had poorer follow-up scores on 3 of 4 BASC-SR global scales: Emotional Symptoms (ß = 0.8, SE = 0.3, P = .003), Clinical Maladjustment (ß = 0.7, SE = 0.3, P = .02), and Personal Adjustment (ß = -0.8, SE = 0.2, P = .002). Associations were stronger with posterior-occlusal (chewing) surfaces, where degradation of composite was more likely. For CBCL change, associations were not statistically significant. At-risk or clinically significant scores were more common among children with greater exposure for CBCL Total Problem Behaviors (16.3% vs 11.2%, P-trend = .01) and numerous BASC-SR syndromes (eg, ≥ 13 vs 0 surface-years, Interpersonal Relations 13.7% vs 4.8%, P-trend = .01). No associations were found with compomer, nor with amalgam exposure levels among children randomized to amalgam. CONCLUSIONS: Greater exposure to bisGMA-based dental composite restorations was associated with impaired psychosocial function in children, whereas no adverse psychosocial outcomes were observed with greater urethane dimethacrylate-based compomer or amalgam treatment levels.

Bisphenol A blood and saliva levels prior to and after dental sealant placement in adults.

PURPOSE: This study examined the effects of a widely used (Delton Pit & Fissure Sealant - Light Cure Opaque, DENTSPLY Professional, York, PA) pit and fissure sealant material on bisphenol A (BPA) levels in blood and saliva, among both low and high-dose groups over time. METHODS: A convenience sample of 30 adults from the Old Dominion University population were randomly and evenly divided into 2 independent variable groups: a low-dose group (1 occlusal sealant application) and high-dose group (4 occlusal sealant applications). A 2 group, time series design was used to examine the presence and concentration of BPA in serum and saliva after sealant placement. Differences comparing low-dose and high-dose groups were examined 1 hour prior (baseline), 1 hour post, 3 hours post and 24 hours after sealant placement, as measured by a direct-competitive BPA Enzyme Linked ImmunoSorbent Assay (ELISA). Hypothesized outcomes were evaluated by applying a parametric, 2 way ANOVA for repeated measures technique to data on the 30 participants ranging in age from 18 to 40 years, and were of mixed gender and ethnicity. RESULTS: BPA was detected in the saliva of all participants prior to sealant placement and ranged from 0.07 to 6.00 ng/ml at baseline. Salivary BPA concentration levels peaked over a 3 hour period following sealant placement and returned to baseline levels within 24 hours. BPA was significantly elevated at all post-sealant placement time periods for both the low-dose (1 occlusal sealant application) and high-dose (4 occlusal sealant applications) groups with peak levels of 3.98 ng/ml and 9.08 ng/ml, respectively. The blood serum did not contain BPA at any point in this investigation. CONCLUSIONS: Exposure to BPA from sources other than dental resins contributes to salivary baseline concentration levels and indicates environmental exposure and use of products containing BPA. Use of specific molecular formulations of dental sealant material determines the release of BPA, therefore, dental sealant materials should be reviewed independently when questioning the release of BPA from dental sealants. In addition, dosage amounts of the dental sealant material used in this study do not influence the serum concentration levels of BPA. Further research is needed to examine the cumulative estrogenic effects of BPA from dental sealants.

Real-time xCELLigence impedance analysis of the cytotoxicity of dental composite components on human gingival fibroblasts.

OBJECTIVES: Aim of this study was by continuous monitoring to assay the proliferative capacity of human gingival fibroblasts (HGFs), to investigate cytotoxicity of the most common monomers/comonomers in dental resin composites: bisphenol-A-glycidylmethacrylate (BisGMA), hydroxyethylenemethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), and urethanedimethacrylate (UDMA) in HGFs during 24h exposure using the xCELLigence system. METHODS: xCELLigence cell index (CI) impedance measurements were performed according to the instructions of the supplier. HGFs were resuspended in medium and subsequently adjusted to 400,000, 200,000, 100,000, and 50,000 cells/mL. After seeding 100 microL of the cell suspensions into the wells of the E-plate 96, HGFs were monitored every 15 min for a period of up to 18 h by the xCELLigence system. RESULTS: Half maximum effect concentrations (EC(50)) were determined based on the dose-response curves derived by xCELLigence measurements. Following real-time analysis, significantly increased EC(50) values of HGFs exposed for 24h to the following substances were obtained: HEMA(a), TEGDMA(b), UDMA(c). The EC(50) values (mean [mmol/L]+/-S.E.M.; n=5) were: HEMA 11.20+/-0.3, TEGDMA(a) 3.61+/-0.2, UDMA(a,b) 0.20+/-0.1, and BisGMA(a,b,c) 0.08+/-0.1. These results are similar to the EC(50) values previously observed with the XTT end-point assay. SIGNIFICANCE: Our data suggests that the xCELLigence live cell analysis system offers dynamic live cell monitoring and combines high data acquisition rates with ease of handling. Therefore, the xCELLigence system can be used as a rapid monitoring tool for cellular viability and be applied in toxicity testing of xenobiotics using in vitro cell cultures.

Clinical results of an open prospective study of a bis-GMA composite in percutaneous vertebral augmentation.

In this open prospective trial, 53 patients with acute pain from osteoporotic vertebral fracture related to osteoporosis or malignancy underwent vertebral augmentation with a new bisphenol-a-glycidyl dimethacrylate (bis-GMA) resin (Cortoss, Orthovita, Malvern, Pa, USA). Treatment consisted of up to 8 ml of Cortoss injected into a given vertebra. The procedure encompassed single and multiple injections (including the contralateral hemivertebra, to a maximum of 3 vertebral levels). Follow-up was at 4 and 8 days and at 1, 3, and 6 months. The primary efficacy end point was patient-rated pain using a 100-point visual analog scale (VAS, with 100 as severest pain) on day 4 following treatment; secondary end points were analgesic use and quality-of-life and disability scores from the Oswestry Disability Index (ODI) and a short-form 12-item questionnaire (SF-12). The present report contains interim results collected up to the 1-month post-treatment time point. At baseline, the group's mean VAS score was 69, indicating moderate to severe pain; at day 4, 32 of 53 patients (60.4%) reported a 30% or greater reduction in baseline pain accompanied by a VAS pain score less than 50 (mean 38.1). Pain reduction was maintained at 1 month (mean VAS 31.3). The average ODI score at baseline was 55, suggesting significant disability among participants prior to Cortoss treatment. Following treatment, the ODI scores were significantly reduced from these baseline levels (day 8, 47.4; 1 month, 33.6). Further, SF-12 physical and mental component scores at 1 month after treatment increased from baseline by 26% and 11%, respectively; while analgesic use decreased concomitantly, primarily among patients with underlying osteoporosis. A total of 20 adverse events were deemed to be device-related. The most frequent clinically significant adverse events attributed to Cortoss were leakage of Cortoss from within the vertebral body at placement (12%), back pain (7%), and unspecified pain (7%). These results indicate that vertebral augmentation with Cortoss rapidly reduces pain, decreases disability, and improves physical functioning in patients with painful vertebral compression fractures.

The in vivo effects of bisGMA on murine uterine weight, nucleic acids and collagen.

The aim of this investigation was to evaluate the ability of commercial bisGMA to stimulate growth in an estrogen-sensitive target tissue. Adult, female, Swiss-Webster mice were ovariectomized and received either oil, estradiol (100 microg/kg), or one of two bisGMA doses (25 microg/kg or 100 microg/kg). Starting on the day of surgery, the hormone, drug or oil was injected subcutaneously 3 times a week. After 3 wk of treatment, the animals were sacrificed, the uteri removed, weighed and stored at -80 degrees C for biochemical analysis. The uteri from ovariectomized mice receiving high dose (100 microg/kg) bisGMA or estradiol showed a significant increase in normalized wet weight that was 29% and 786%, respectively, greater than the ovariectomized control uterine normalized weights. In the low bisGMA dose (25 microg/kg) group, normalized uterine wet weights were not statistically significant from ovariectomized controls. Biochemical analyses of uterine tissues revealed that estradiol resulted in maintaining DNA content, RNA content, RNA/DNA ratios and collagen content significantly above the ovariectomized control. Neither the low nor high doses of bisGMA stimulated RNA content, DNA content or RNA/DNA ratios above ovariectomized controls. However, the high dose (100 microg/kg) of bisGMA caused a significant increase above ovariectomized controls in uterine collagen content.