Kamran Gulsahi

Microleakage beneath ceramic and metal brackets bonded with a conventional and an antibacterial adhesive system.

OBJECTIVE To assess microleakage of a tooth-adhesive-bracket complex when metal or ceramic brackets were bonded with a conventional and an antibacterial self-etching adhesive. MATERIALS AND METHODS Forty freshly extracted human premolars were randomly assigned to four equal groups and received the following treatments: group 1 = Transbond XT + metal bracket, group 2 = Transbond XT + ceramic bracket, group 3 = Clearfil Protect Bond + ceramic bracket, and group 4 = Clearfil Protect Bond + metal bracket. After photopolymerization, the teeth were kept in distilled water for 1 month and thereafter subjected to thermal cycling (500 cycles). Specimens were further sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned and examined under a stereomicroscope, and scored for marginal microleakage for the adhesive-tooth and bracket-adhesive interfaces from incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis test and Mann-Whitney U-test with Bonferroni correction. RESULTS All groups demonstrated microleakage between the adhesive-enamel and bracket-adhesive interfaces. A significant difference was observed among all groups (P < .05) for the microleakage between the bracket-adhesive interface. Metal brackets exhibited significantly more microleakage than did ceramic brackets between the bracket-adhesive interface with either of the adhesives. Clearfil Protect Bond exhibited results similar to Transbond XT. Clearfil Protect Bond may be a choice of adhesive in bracket bonding because of its antibacterial activity and similar microleakage results with the orthodontic adhesive. CONCLUSIONS Metal brackets cause more leakage between an adhesive-bracket interface, which may lead to lower clinical shear bond strength and white-spot lesions.

Time-dependent Conversion of a Methacrylate-based Sealer Polymerized with Different Light-curing Units

The purpose of this study was to investigate the degree of conversion of a methacrylate-based sealer (Epiphany; Pentron Clinical Technologies, Wallingford, CT) with regard to the method of photoactivation, distance from the light-curing unit (LCU), and post-curing time. Freshly mixed Epiphany sealer was dispensed into half-pipe-shaped silicone moulds (n = 48), after which the specimens were photoactivated with one of the following LCUs from the coronal aspect: (1) quartz tungsten halogen/40 seconds and (2) light-emitting diode/20 seconds. In each specimen, the degree of conversion was measured at three different locations (coronal, middle, and apical) using Fourier transform infrared spectroscopy before and after photoactivation. The amount of conversion was approximately 50% after photoactivation and improved by approximately 10% after 15 days. Conversion of Epiphany was not affected by the type of LCU (p > 0.001) or the distance from the LCU (p > 0.001) but showed a significant increase within time (p < 0.001). These results indicate incomplete polymerization of Epiphany, despite a post-curing time of as long as 2 weeks in vitro.

Assessment of possible risk indicators for apical periodontitis in root-filled teeth in an adult Turkish population

OBJECTIVE The objective of this study was to determine possible independent risk indicators of apical periodontitis (AP) in root-filled teeth in an adult Turkish population. STUDY DESIGN This study included subjects older than 15 years who had 1 or more root-filled teeth examined at the Baskent University Faculty of Dentistry. A total of 812 root-filled teeth were evaluated in 425 individuals. AP was the dependent variable and age, gender, length and density of root fillings, presence of periodontal problems, posts, localization of tooth, and tooth type were identified as independent variables. Generalized Estimating Equation (GEE) models were used in statistical analysis. RESULTS AP was detected on 148 teeth (18.2%) in 812 root-filled teeth. According to multiple GEE model, males were more likely to have AP than females. Of the dental variables, length of root fillings, periodontal problems and tooth type were significantly associated with AP. CONCLUSIONS The present study indicates that to be male and dental variables including length of root fillings, periodontal problems, and molar teeth were significantly associated with AP.

Effect of sodium ascorbate on bond strength of different adhesive systems to NaOCl-treated dentin

The aim of this study was to evaluate the effects of sodium ascorbate on bond strength of different adhesive systems to NaOCl-treated dentin. Eighty extracted molar teeth were used in the study. The buccal enamel surfaces were removed to obtain a flat dentin surface. The teeth were mounted in self-curing resin and dentin surfaces were irrigated with NaOCl for 10 min. Half of the specimens were treated with sodium ascorbate for 10 min. The teeth were randomly assigned to four subgroups according to the adhesive systems used (Clearfil SE Bond, Clearfil Tri-S Bond, Adper Prompt-L-Pop, Adper Single Bond 2). Bond strengths were determined with a Universal Testing Machine, at a crosshead speed of 0.5 mm/min. Data were statistically analysed using anova at a significance level of 0.05. Two-way ANOVA revealed that the effect of sodium ascorbate application on bond strength of adhesive systems to NaOCl-treated dentin was statistically significant (P < 0.05). The bond strength results were significantly influenced by the application of sodium ascorbate (P < 0.05) and there was a significant difference between the adhesive systems (P < 0.05). Although statistically significant differences were not demonstrated in all adhesive resin groups, sodium ascorbate application after NaOCl treatment improved the bond strength values.

Effect of bleaching agents on sealing properties of different intraorifice barriers and root filling materials

Objective: To evaluate the effect of intracoronal bleaching agents on the sealing properties of different intraorifice barriers and root filling materials. Study Design: The root canals of extracted human premolars (n=180) were prepared by using System GT rotary files and filled with either gutta-percha+AH Plus or Resilon+Epiphany sealer. In both groups, the coronal 3mm of root filling was removed and replaced with one of the following materials applied as intraorifice barriers (n=30/group): 1. ProProot-MTA; 2. Conventional Glass ionomer cement; and 3. Hybrid resin composite. In each subgroup, intracoronal bleaching was performed using either sodium perborate with distilled water or 35% hydrogen peroxide gel for 3 weeks. The leakage of specimens was measured using fluid-filtration and dye penetration tests. The data were analyzed statistically with One-way ANOVA, Repeated Measures t-test and Independent Samples t-test (p=0.05). Results: The fluid conductance values of the test groups were not influenced by the type of the bleaching agent, the intraorifice barrier, or the root filling material (all p>0.05). However, the extent of dye leakage was significantly affected by the type of intraorifice barrier material (p<0.05), which showed the following statistical ranking: glass ionomer cement > resin composite > ProRoot-MTA (p<0.05). Conclusions: The effect of 35% hydrogen peroxide gel or sodium perborate/distilled water on the sealing properties of tested intraorifice barriers and root filling materials varied conforming leakage assessment. These properties were not affected by using fluid filtration test, while the glass ionomer barrier showed the greatest amount of dye leakage in both gutta-percha and Resilon root-filled teeth. Key words:Tooth Bleaching, root canal filling materials, glass ionomer cement, mineral trioxide aggregate, micro leakage

Change in Periapical Lesion and Adjacent Mucosal Thickening Dimensions One Year after Endodontic Treatment: Volumetric Cone-beam Computed Tomography Assessment

Introduction: Changes in periapical lesion dimensions along with mucosal thickening after endodontic treatment have not been studied yet. Therefore, the objectives of this study were (1) to obtain linear and volumetric measurements of lesion dimensions in maxillary first molars with periapical pathology and (2) to measure maxillary sinus mucosal thickening in the vicinity of periapical lesions before and 1 year after endodontic treatment by using cone‐beam computed tomography (CBCT). Methods: Twenty‐one maxillary first molar teeth of 21 patients (14 female and 7 male) with periapical lesion that had local mucosal thickening in the vicinity of the periapical lesion were endodontically treated. A total of 21 maxillary first molar roots (8 mesiobuccal roots, 6 distobuccal roots, and 7 palatal roots), each one from different patients, was included. Pretreatment and 1‐year post‐treatment CBCT images of each tooth were obtained by using Kodak CS 9300 3D CBCT unit. Width, height, surface area, and volume measurements of periapical lesions and mucosal thickening of the maxillary sinus mucosa in the vicinity of the periapical lesion were measured before and 1 year after endodontic treatment. General linear model (analysis of variance) was used for the comparisons between measurements, and significance was set at P < .05. Regression analysis was also used to test the correlation between different measurements. Results: We found statistically significant differences between mean pretreatment and mean post‐treatment measurements conducted by using CBCT images (width, P = .002; height, P < .001; maximum mucosal thickening, P < .001; medium mucosal thickening, P < .001; minimum mucosal thickening, P < .001; surface area, P = .032; and volume, P = .034). Considering gender, age, and root‐type variables, no significant differences were found for all the measurements conducted (P > .05). There were 36%, 41%, 53%, 54%, 53%, 73%, and 75% mean reductions in lesion width, lesion height, maximum sinus mucosal thickness, medium sinus mucosal thickness, minimum sinus mucosal thickness, lesion surface area, and lesion volume, respectively, before and 1 year after endodontic treatment. Regression analysis of pretreatment lesion volume versus percentage of post‐treatment lesion volume change revealed a low regression coefficient (R2 = 16.7%, P > .05), showing a weak linear relationship. Conclusions: CBCT assessment of changes in periapical lesion and mucosal thickening dimensions may reveal useful information regarding endodontic treatment success.

Benign Paroxysmal Positional Vertigo After Nonotologic Surgery: Case Series

Benign paroxysmal positional vertigo is one of the most common types of vertigo caused by peripheral vestibular dysfunction. Although head trauma, migraine, long-term bed rest, Ménière disease, viral labyrinthitis, and upper respiratory tract infections are believed to be predisposing factors, most cases of benign paroxysmal positional vertigo are idiopathic. Ear surgery is another cause, but after non-otologic surgery, attacks of benign paroxysmal positional vertigo are rare. We describe three cases of benign paroxysmal positional vertigo attacks after non-otologic surgery (one patient after a nasal septoplasty and two patients after dental endodontic treatment) and discuss the pathophysiological mechanism of benign paroxysmal positional vertigo seen after non-otologic surgery, its diagnosis and treatment.

Influence of Dynamic Loading and Different Adhesive Systems on the Microleakage in Root Canals

Abstract The objective of this study was to evaluate the influence of dynamic loading and different adhesive systems on the microleakage in root canals. 80 human premolars were used in this study. The crowns of the teeth were sectioned at the cemento-enamel junction using a low speed diamond saw. After post space preparation, the roots were randomly assigned to 4 groups (n = 20) and restored with different adhesive systems. Group 1: Rely X ARC (RA) + Single Bond (SA), Group 2: Clearfil SA Cement (CL), Group 3: Panavia F 2.0 (PAN), Group 4: Rely X Unicem (RU). All the teeth were restored with the same type of glass fiber post and coronal cores built up with light-polymerizing hybrid composite resin. Half of the specimens of each group (n = 10) were subjected to additional dynamic loading in a universal testing machine. Apical parts of the roots were attached to computerized fluid filtration device for leakage measurement. The two-way ANOVA test was used first to detect overall significance, followed by two-sample t-test to identify which pairs of groups had significant differences. For each outcome statistical significance was set at p < 0.05. Dynamic loading significantly increased the microleakage values for Rely X ARC (p = 0.005), Clearfil SA Cement (p = 0.002) and Rely X Unicem groups (p = 0.001) but Panavia F 2.0 group was not affected by the dynamic loading (p = 0.111). One-way ANOVA test was applied to detect any significant differences in microleakage values for the adhesive systems. In the unloaded groups, there is no difference between the adhesive systems (p = 0.13). For the dynamically loaded groups, there is only significant difference between PAN and RA groups (p = 0.010). Post-hoc pairwise comparisons were done using Tukey’s multiple comparisons. Differences between Rely X ARC-Clearfil SA Cement and Rely X ARC-Panavia F 2.0 are statistically significant (p = 0.009, 0.013).

A Comparison of Er:YAG Laser with Photon-Initiated Photoacoustic Streaming, Nd:YAG Laser, and Conventional Irrigation on the Eradication of Root Dentinal Tubule Infection by Enterococcus faecalis Biofilms: A Scanning Electron Microscopy Study

This study evaluated the antimicrobial efficacy of Er:YAG laser activation with photon-initiated photoacoustic streaming (PIPS), Nd:YAG laser disinfection, and conventional irrigation on Enterococcus faecalis biofilms using scanning electron microscopy (SEM). Biofilms were grown on 110 root halves and divided into the following: Groups 1 and 2 (saline and 1% NaOCl with apical position of PIPS, resp.), Groups 3 and 4 (saline and 1% NaOCl with coronal position of PIPS, resp.), Groups 5 and 6 (Nd:YAG laser after saline and 1% NaOCl irrigation, resp.) and Groups 7, 8, and 9 (conventional irrigation with 1% NaOCl, 6% NaOCl, and saline, resp.). SEM images of the apical, middle, and coronal levels were examined using a scoring system. Score differences between Groups 1 and 2 were insignificant at all levels in the remaining biofilm. Group 4 had significantly greater bacterial elimination than Group 3 at all levels. Differences in Nd:YAG laser irradiation between Groups 5 and 6 were insignificant. Groups 7 and 8 were insignificantly different, except at the middle level. Saline group had a higher percentage of biofilms than the others. In this study, PIPS activation with NaOCl eliminates more E. faecalis biofilms in all root canals regardless of the position of the fiber tip.

Effect of adhesive systems on microleakage in endodontically treated teeth restored with glass fiber posts

The effect of adhesive systems on microleakage in endodontically treated teeth restored with glass fiber posts was studied. Forty carious and crack-free premolars were prepared using a stepback technique and obturated with gutta-percha. The endodontically treated roots were randomly divided into four groups (n = 10). Glass fiber posts cemented following adhesive luting agents; group 1: All Bond 3/Duo Link (ALB/DL), group 2: One-Step Plus/Duo-Link (OSP/DL), group 3: Panavia F 2.0/Panavia ED Primer II (PAN/ED), and group 4: Rely X Unicem (RU). All specimens were thermal cycled and stored in basic fuchsin solution for one week. The roots were sectioned horizontally into three sections: apical, middle, and coronal. The occlusal direction of each section was digitally photographed under a stereomicroscope. Dye penetration area was calculated as the basic fuchsin infiltrated surface divided by total dentin. The data were statistically analyzed using the Mann–Whitney U and Wilcoxon Signed Ranks Tests (α = 0.05). The mean area measurements were ranged between 0 and 3.7357. According to the Mann–Whitney U test, there was no significant difference among the groups and sections (p > 0.05). Intragroup comparisons showed a significant difference between coronal-apical and middle-coronal sections in Panavia group (p = 0.043) by Wilcoxon Signed Test. It was found that there was no significant difference among four groups and the apical, coronal, and middle sections. The only difference was found for the group of PAN/ED between coronal-apical and coronal-middle sections.