Comparison of three adhesive systems in class II composite restorations in endodontically treated teeth: Influence of Er:YAG laser conditioning and gingival margin levels on microleakage.

BACKGROUND: Dental surface conditioning by Er:YAG laser is currently being investigated, as not all of the mechanisms and effects of this technique have been clearly studied. Thus, the aim of the present study was to assess the cervical microleakage of Class II resin composite restorations in endodontically treated teeth following either the respective conventional conditioning or additional Er:YAG laser conditioning, in association with varied adhesives. MATERIAL AND METHODS: Standardized mesial-occlusal-distal cavities (two gingival walls positioned in dentin and enamel, respectively) were created in 60 extracted human premolar teeth. Following the completion of the endodontic therapy, the teeth were grouped into six categories based on conditioning modality and adhesive strategy as follows: group 1-37% phosphoric acid/Adper Single Bond 2 (ASB2); group 2-Er:YAG laser/37% phosphoric acid/ASB2; group 3-Clearfil SE Bond (CSE); group 4-Er:YAG laser/CSE; group 5-Adper Easy One (AEO); and group 6-Er:YAG laser/AEO. Specimens were submitted to thermocycling and dye penetration, followed by longitudinal sectioning. The dye penetration was evaluated using a stereomicroscope. One specimen from each group was assessed under a scanning electron microscope for adhesive interface analysis. RESULTS: No significant differences were found between the conditioning modalities, nor between the adhesive systems at both margins. Groups 1 and 2 showed a lower degree of microleakage in the enamel vs. dentin (p = 0.002). Group 2 showed a significantly lower incidence of microleakage in enamel vs. dentin (p = 0.005). CONCLUSIONS: CSE and AEO were comparable with that of ASB2 regarding sealing ability. Additional Er:YAG laser conditioning may be beneficial before ASB2 application in enamel. Key words:Endodontically treated teeth, etch-and-rinse adhesive, Er:YAG laser, gingival level, sealing ability, self-etch adhesive.

Odontogenic effects of two calcium silicate-based biomaterials in human dental pulp cells.

BACKGROUND: The goal of treating exposed pulp with an appropriate pulp capping material is to promote the dentinogenic potential of the pulpal cells. There have been recent attempts to develop more effective pulp-capping materials. OBJECTIVES: The aim of this study was to evaluate the effect of newly developed calcium silicate-based material on odontogenic differentiation of primary human dental pulp cells (HDPCs), in comparison with a contemporary calcium silicate-based material. MATERIAL AND METHODS: Human dental pulp cells isolated from dental pulps were cultured in standard culture conditions in Dulbecco's Modified Eagle's Medium (DMEM) and then the effects of Micro-Mega mineral trioxide aggregate (MM-MTA) (Micro-Mega, Besançon, France) and ProRoot MTA (MTA) (Dentsply Sirona, Tulsa, USA) (positive control) were evaluated on HDPCs at 1, 7 and 14 days. Untreated cells were used as a negative control. Odontoblastic differentiation was assessed by alkaline phosphatase (ALP) activity. Runtrelated transcription factor 2 (RUNX2), alkaline phosphatase liver/bone/kidney (ALPL), bone morphogenetic protein 2 (BMP2), dentin sialophosphoprotein (DSPP), and Distal-less homeobox 3 (DLX3), as odontoblastic/ osteoblastic expression markers, were evaluated by semi-quantitative real-time polymerase chain reaction (RT-PCR) analysis. Calcium levels of culture media were also determined. RESULTS: The MM-MTA group significantly increased the expression of BMP2 compared with that of the MTA group at 3 different time periods (p < 0.05). The up-regulation of ALPL between day 1 and 14 and the up-regulation of DSPP between day 7 and 14 were significant in both groups (p < 0.05). Micro-Mega MTA and MTA exhibited similar messenger RNA (mRNA) expression levels of ALPL, DSPP, RUNX2, DLX3, and ALP activities, as well as calcium levels. CONCLUSIONS: Based on the cell responses observed in this study, MM-MTA might be used efficiently in dental pulp therapy as a potential alternative to MTA.

Comparison of Three Final Irrigation Activation Techniques: Effects on Canal Cleanness, Smear Layer Removal, and Dentinal Tubule Penetration of Two Root Canal Sealers.

OBJECTIVE: The aim of this study was to compare three final irrigation activation techniques with respect to their effects on debridement efficacy, smear layer removal, and dentinal tubule penetration of two different root canal sealers. BACKGROUND DATA: Different applications to improve the delivery of irrigating solutions within the root canal system are currently being investigated, as not all of the mechanisms and effects of these techniques have been clearly identified. MATERIALS AND METHODS: One hundred forty-two single-rooted teeth were randomly divided into a control group and three experimental groups based on the irrigant activation technique used: EndoVac (EV) system, photon-induced photoacoustic streaming (PIPS), and conventional syringe irrigation (CSI). Thirteen specimens from each experimental group were evaluated for debris and smear layer removal using scanning electron microscopy. The remaining 30 specimens per group were divided into two subgroups according to the root canal sealer used: AH Plus and TotalFill BC. The maximum depth and total percentage of sealer penetration were measured using confocal laser scanning microscopy. RESULTS: PIPS resulted in significantly less debris in the middle third of the root canal compared with CSI (p < 0.01). There were no significant differences among CSI, EV, and PIPS concerning debris removal at coronal and apical levels or smear layer removal at all levels (p > 0.05). TotalFill BC use after final irrigation with EV and CSI at 2 mm or PIPS at 5 mm exhibited a significantly higher percentage of sealer penetration than that with AH Plus (p < 0.05). When AH Plus was used, PIPS allowed deeper sealer penetration than CSI at 2 mm (p < 0.05). CONCLUSIONS: The effects of EV, PIPS, and CSI on debridement efficacy, smear layer removal, and dentinal tubule penetration were almost comparable. TotalFill BC showed superior tubular penetration than AH Plus.

Incidence of root canal treatment of second molars following adjacent impacted third molar extraction.

BACKGROUND/PURPOSE: The aim of this study was to evaluate the incidence of requirement for root canal treatment of adjacent second molars following the surgical extraction of an impacted third molar. MATERIALS AND METHODS: The dental records of 6323 consecutive patients who had impacted third molars removed surgically were evaluated and the incidence of postoperative root canal treatment requirement of adjacent second molars was determined. Patients who required root canal treatment of neighboring second molars were accepted as the study group, while the remaining patients were accepted as a control group. Sex, age at the time of the operation, localization of third molar, the depth of impaction, angulation of the tooth, and the professional experience of the surgeon performing the operation were evaluated from patient records. RESULTS: The incidence of requirement of root canal treatment for second molars following a neighboring impacted third molar extraction was 0.17% (11/6323) and invariably occurred in the mandible. The mean age of the study group was found to be significantly higher than the control group (31 years vs. 23 years). The years of professional experience of the surgeons was significantly lower in the study group than in the control group. CONCLUSION: Although the incidence is minimal, iatrogenic subluxation injuries occurring during the surgical removal of impacted third molars can lead to pulpal complications and a requirement for root canal treatment of adjacent second molars.

The evaluation of endodontic flare-ups and their relationship to various risk factors.

BACKGROUND: To evaluate the incidence of flare-ups and identify the risk factors including age, gender, tooth type, number of root canals, initial diagnosis, the type of irrigation regimen, treatment modality and the number of visits, in patients who received root canal treatment from January 2002 to January 2008. METHODS: Records of 1819 teeth belonging to 1410 patients treated by 1 endodontics specialist during 6-year period were kept. Patient, tooth, and treatment characteristics were evaluated and the relationships between these characteristics and flare-ups were studied. Statistical analysis was carried out by using Pearson Chi-square test, Fisher's Exact test, and Binary Logistic regression analyses. RESULTS: The incidence of flare-ups was 59 (3.2 %) out of 1819 teeth that received endodontic therapy. Pulpal necrosis without periapical pathosis was the most common indication for flare-up (6 %) (p < 0.01). Teeth undergoing multiple visits had a higher risk of developing flare-ups compared to those with single appointments (OR: 3.14, CI: 1.414-7.009, p < 0.01). There were also no statistically significant differences in the incidence of flare-ups regarding to age, gender, tooth type, number of root canals, treatment modality, and the irrigation solutions that used during the treatment. CONCLUSIONS: The incidence of flare-up is minimal when teeth are treated in one visit. Absence of a periapical lesion in necrotic teeth is a significant risk factor for flare-ups.

Extrusão cirúrgica de um dente com fratura coronorradicular: acompanhamento de 3.5 anos / Surgical extrusion of a crown-root fractured tooth: 3.5-year follow-up

Introdução: diferentes abordagens de tratamento sãoindicadas para dentes com fraturas coronorradiculares.A extrusão cirúrgica é um procedimento único, que envolveo reposicionamento imediato do dente à sua posiçãonormal. Objetivo: o objetivo deste relato de casofoi apresentar o tratamento multidisciplinar de um pré--molar superior com fratura coronorradicular. Métodos:neste caso, um pré-molar superior fraturado foi tratadopor meio da técnica de extrusão cirúrgica. Após aresolução da lesão periapical, o dente foi restauradocom coroa metalocerâmica. Resultados: após 3,5 anosde acompanhamento, o dente não apresentou sintomasou sinais clínicos e radiográficos de reabsorção radicularprogressiva, de perda óssea marginal ou de doença periapical.Conclusão: os resultados favoráveis do casodemonstram que a extrusão cirúrgica pode ser uma alternativade tratamento para os protocolos existentes.

Effect of Er,Cr:YSGG laser irradiation on apical sealing ability of calcium silicatecontaining endodontic materials in root-end cavities.

The aim of this research was to evaluate the apical sealing abilities of 60 root-end cavities filled with mineral trioxide aggregate (MTA) and iRoot BP cements after treated with either 17% EDTA solution or Er,Cr:YSGG laser irradiation. After the filling procedure, apical leakage quantity was measured at 4 weeks using a fluid filtration method. One root from each group was processed for scanning electron microscopy and energy dispersive X-ray spectroscopy analyses. Both EDTA/MTA and laser irradiation/MTA combinations showed significantly lower microleakage than EDTA/iRoot BP and laser irradiation/iRoot BP combinations (p<0.05). Between groups of the same filling material, there were no significant differences among specimens treated with EDTA or laser (p>0.05). Both MTA and iRoot-BP demonstrated tag-like structures within the dentinal tubules when used in conjunction with EDTA.

Rehydration of a reattached fractured tooth fragment after prolonged dehydration.

Crown fractures of the anterior teeth are one of the most common outcomes of trauma to the orofacial region. The reattachment of dental fragments is a conservative treatment and should be considered a primary treatment choice in the restoration of anterior tooth fractures. This article presents a clinical technique for the restoration of a fractured maxillary lateral incisor by reattaching the tooth fragment that was kept in dry conditions for five days with the aid of adhesive dentistry. The esthetic compromise of white color (due to excessive dehydration of the segment) was reconciled after one month of service in the mouth by regaining the natural color by rehydration. The one-year clinical evaluation revealed a successful outcome for this technique, and the patient was pleased with the esthetic results of the conservative treatment modality.

Evaluating the potential key factors in assessing the morphology of mesiobuccal canal in maxillary first and second molars.

The purpose of this study was to provide further information on the morphology of the root canals and pulp chambers of 100 maxillary first and 100 maxillary second molars, with particular reference to the anatomical relationship of the root canal patterns and the distance between mesiobuccal (MB) and mesiolingual (ML) orifices. Each transverse section was digitally imaged to measure the interorificial distance using a stereomicroscope. The angles of primary curvatures were determined in both buccolingual (clinic view, CV) and mesiodistal (proximal view, PV) directions and the canal configuration of the MB root was classified according to the Weine classification. The rhomboidal pulp chamber floor morphology predominated in each tooth type. The mean interorificial distance in both maxillary first and second molars was significantly shorter in type II compared with type III (P < 0.05). The interorificial distance was correlated with the primary curvature of MB canal in PV in maxillary first molars (P < 0.05), whereas the primary curvature of ML canal in CV was correlated with the primary curvature of ML canal in PV in maxillary second molars (P < 0.01). The evaluation of interorificial distance in both types of maxillary molars and the curvature of ML canal in CV in maxillary second molar can give valuable information to the clinician.

Effect of Er,Cr:YSGG laser irradiation on the apical sealing ability of AH Plus/gutta-percha and Hybrid Root Seal/Resilon Combinations.

OBJECTIVE: The objective of this study was to evaluate the sealing ability of 2 different resin-based endodontic filling systems after smear layer removal with 2 different techniques. STUDY DESIGN: Extracted human single-rooted teeth (n = 74) were instrumented using HERO Shaper rotary instruments and irrigated with 1 mL of 2.5% NaOCl between each instrument. Additionally, the canals received either an extra 3-minute rinse with 2 mL of 17% EDTA or a 40-second Er,Cr:YSGG laser treatment. The root canals were filled with either Hybrid Root Seal/Resilon combination or AH Plus/gutta-percha combination using lateral condensation technique (n = 11). Apical leakage quantity was measured with the computerized fluid filtration meter at 1 and 4 weeks. One root from each group, which was not submitted to the fluid filtration test, was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using 3-way ANOVA and the post hoc Tukey HSD test (α = 0.05). RESULTS: A significant decrease was observed in the microleakage values of all the experimental groups tested with time (P < .0001). EDTA + AH Plus/gutta-percha combination exhibited the least microleakage, whereas laser irradiation + Hybrid Root Seal/Resilon combination showed the greatest microleakage at each of the 2 time periods. Each experimental combination exhibited architecture in SEM that seemed to correlate with its sealing performance. CONCLUSION: Er,Cr:YSGG laser treatment does not enhance the sealing ability of the sealers compared with EDTA application. The root canal adaptation and sealing ability of the Hybrid Root Seal/Resilon combination is not superior to that of the AH Plus/gutta-percha combination.

Evaluation of antifungal efficacy of erbium, chromium: yttrium-scandium-gallium-garnet laser against Candida albicans.

OBJECTIVE: The purpose of this in vitro study was to investigate the ability of Er,Cr:YSGG laser irradiation at different energy settings to eliminate Candida albicans, either with or without 5.25% sodium hypochlorite (NaOCl) treatment. METHODS: In total, 90 extracted human single-rooted teeth were shaped by using a crown-down technique with HERO Shaper rotary instruments and irrigated with 1 mL of 2.5% NaOCl between each instrument. The specimens were autoclaved and incubated with a suspension of C. albicans (ATCC 90028). Then the specimens were divided into six treatment groups (n = 15 per group): group 1, NaOCl + 1-W laser; group 2, 1-W laser; group 3, NaOCl + 0.75-W laser; group 4, 0.75-W laser, group 5, NaOCl; and group 6, no treatment. Aliquots of the experimental teeth were transferred onto Sabouraud's dextrose agar plates with paper points, and colony-forming units (CFUs) were counted as a measure of antifungal activity. One root from each group, which was not submitted to the sampling procedure, was fixed in glutaraldehyde, split into two halves, and evaluated with scanning electron microscopy (SEM). Statistical analysis was performed by using analysis of variance (ANOVA) and the Dunnett t test. Significance was set at alpha = 0.05. RESULTS: All the treatment groups resulted in a significant reduction of C. albicans, but no sterilization, and all the groups were significantly different from each other (p < 0.0001). Group 1 (NaOCl and 1-W laser combination) exhibited the greatest reduction, whereas group 5 (NaOCl) resulted in a minimal reduction in CFUs of C. albicans. The SEM observations were in accordance with the microbiologic analysis. CONCLUSIONS: The 5.25% NaOCl and 1-W laser treatment combination may be a valuable cleaning tool for root canals infected with C. albicans.

An in vitro evaluation of the apical sealing ability of new polymeric endodontic filling systems.

OBJECTIVE: The objective of this study was to compare the short-term sealing abilities of recently introduced polymeric endodontic filling systems. STUDY DESIGN: Root canals of 120 extracted and decoronated human single-rooted teeth were instrumented using crown-down technique with HERO Shaper rotary instruments. The roots were divided randomly into 8 groups (6 experimental and 2 control groups of 15 roots each) and filled with different combinations of core and sealer as follows: group 1, RealSeal/Resilon; group 2, RealSeal/Herofill; group 3, Hybrid Root Seal/Resilon; group 4, Hybrid Root Seal/Herofill; group 5, MM-Seal/Resilon; group 6, MM-Seal/Herofill; group 7, positive controls (Herofill only); group 8, negative controls. Apical leakage quantity was evaluated after 1 week by using a fluid filtration model. For each sample, measurements of fluid movement were recorded at 2-minute intervals for a total of 8 minutes, and then averaged. The data were calculated and analyzed using the Kolmogorov-Smirnov test, 1-way analysis of variance (ANOVA), and the Tukey test. Significance was set at P less than .05. RESULTS: Multiple paired comparisons (Tukey test) showed that, of all the groups, MM-Seal/Herofill combination exhibited the least microleakage, and RealSeal/Herofill combination ranked second in this regard. The mean leakage values for the RealSeal/Resilon and MM-Seal/Resilon combinations were both significantly higher than the means for the other 4 experimental groups (P < .01). Hybrid Root Seal combined with Resilon resulted in significantly less microleakage than Hybrid Root Seal combined with Herofill (P = .001). CONCLUSION: The results suggest that the sealing properties of epoxy-resin-based sealer (MM-Seal) combined with gutta-percha (Herofill) are superior to those of methacrylate-based sealers (Hybrid Root Seal and Realseal) combined with Resilon.

Push-out bond strength and SEM evaluation of new polymeric root canal fillings.

OBJECTIVE: The objective of this study was to compare the interfacial strengths and failure modes of new polymeric endodontic obturation systems consisting of different material combinations. STUDY DESIGN: Extracted human single-rooted teeth (n = 105) were instrumented using HERO Shaper rotary instruments and obturated with different combinations of core and sealer as follows: group 1, RealSeal/Resilon; group 2, RealSeal/Herofill; group 3, Hybrid Root Seal/Resilon; group 4, Hybrid Root Seal/Herofill; group 5, MM-Seal/Resilon; group 6, MM-Seal/Herofill; group 7 (control). Failure modes of root slices (1.00 +/- 0.05-mm thick) after push-out testing were examined with stereomicroscope and scanning electron microscopy. RESULTS: Hybrid Root Seal/Resilon combination had significantly greater bond strength than all the other groups (P < .001); RealSeal/Resilon combination proved to have the second highest bond strength (P < .001). Bond failure was mainly mixed failure in both adhesive and cohesive modes at the dentin/sealer interface. CONCLUSION: The push-out bond strengths of methacrylate-based sealers (Hybrid Root Seal and RealSeal) and thermoplastic synthetic-polymer-based core material (Resilon) combinations were higher than epoxy-resin-based sealer (MM-Seal) and gutta-percha (Herofill) combination.

Sealing capacity of a flowable composite, as a protective base, with different conditioning methods in nonvital bleaching.

OBJECTIVE: The purpose of this in vitro study was to determine the microleakage of a nano-flowable composite used as a protective base, applied with different conditioning methods in nonvital bleaching. MATERIALS AND METHODS: Forty root-filled teeth were divided into four treatment groups (n = 10 per group): group 1--Er:YAG laser etching + Adper Single Bond 2; group 2-37% phosphoric acid + Adper Single Bond 2; group 3--Adper Prompt L-Pop; and group 4--No treatment. A nano-flowable composite (Filtek Supreme Flow) base was used in each group. For a 24-h period, 40% hydrogen peroxide solution was applied to the pulp chambers, and they were subsequently subjected to a dye (silver nitrate) challenge for 4 h. After the dye was washed out with water, each tooth was cut in half and both halves were exposed to sunlight for 2 h to promote oxidation of the dye, turning it black. Finally the sections were examined under 4x magnification to determine the degree of leakage as assessed with a four-point scale. Statistical analysis was performed with the Mann-Whitney U test. RESULTS: There were no significant differences between groups 1, 2, and 3 (p > 0.05), but the teeth in group 4 had significantly higher microleakage scores than the teeth in the other groups (p < 0.05). CONCLUSION: Self-etching adhesive application, Er:YAG laser etching, and phosphoric acid etching combined with an adhesive system all showed similar microleakge scores when a nano-flowable composite was applied as a protective base in nonvital bleaching.

In vivo evaluation of the biocompatibility of a new resin-based obturation system.

OBJECTIVE: The aim of this study was to evaluate the in vivo biocompatibility of the new resin-based Epiphany-Resilon root canal filling system after implantation in rat connective tissue. STUDY DESIGN: Thirty-six female Wistar albino rats, 9 months old, weighing 200 to 220 g, were used to evaluate the biocompatibility. Four subcutaneous pockets were created in the back of the rats, and each material (Resilon, gutta-percha, a Teflon tube containing Epiphany, and an empty Teflon tube) was implanted into a specific dorsal site. The empty Teflon tubes were used as control. After 1, 4, and 8 weeks, the implants were removed with the surrounding tissues. The inflammatory tissue reactions were graded after a histopathologic examination. RESULTS: At each time period, there was practically no difference in the reaction of all the implant materials (P > .05). The intensity of the reaction had diminished by the 4-week observation period, and this reduction continued through the 8-week observation period. CONCLUSION: All the tested materials showed an acceptable biocompatibility.

Dental erosion in chronic renal failure.

Dental erosion is a common oral finding in chronic renal failure and may develop due to extrinsic and/or intrinsic causes. The aim of this study was to compare the salivary calcium and phosphorus levels, salivary flow rate, salivary buffer capacity, salivary pH, serum calcium and phosphorus levels and parathyroid hormone levels in chronic renal failure patients with and without dental erosion. Twenty-four men and 19 women who had had chronic renal failure for at least 2 years were studied. Twenty-two subjects displayed erosion-like patterns on their teeth and the other 21 patients showed no signs of erosion. Two closely age- and sex-matched control groups (control groups 1 and 2) were enrolled in this study because of the age disparity between the erosion and non-erosion groups. The data were analyzed by Mann-Whitney U test, Student t test, Pearson's and Spearman's correlation tests. None of the comparisons were statistically different between the erosion and non-erosion groups. There were statistically significant differences in salivary calcium (P < 0.01) and phosphorus (P < 0.01) levels, serum phosphorus level (P < 0.01) and serum PTH level (P < 0.01) for the erosion group and control group 1 and also for the non-erosion group and control group 2. There was also a significant difference in salivary flow rate (P < 0.05) for the erosion group and control group 1. There was a positive significant correlation between saliva buffer capacity and salivary phosphorus level (r = 0.454, P < 0.05) in the erosion group.

An in vitro evaluation of the apical sealing ability of a new resin-based root canal obturation system.

The purpose of this study was to assess the apical sealing ability of the new resin-based Epiphany-Resilon root canal filling system, and to compare this with the sealing abilities of different pairings of AH plus, gutta-percha, Epiphany, and Resilon. Seventy extracted human single-rooted teeth were used. All teeth were instrumented using a set of ProTaper rotary instruments. The canal spaces were filled with different combinations of core and sealer using lateral condensation, as follows: group 1, AH Plus + gutta-percha; group 2, AH Plus + Resilon; group 3, Epiphany + Resilon; group 4, Epiphany + gutta-percha. Apical leakage quantity was measured with the computerized fluid filtration meter. Statistical analysis indicated that Epiphany gutta-percha combination had the least amount of microleakage than all the other groups; AH Plus gutta-percha combination proved to have second least amount of microleakage among the groups. AH Plus-Resilon combination demonstrated the greatest amount of microleakage. There were a significant difference between Epiphany gutta-percha and AH Plus-Resilon combinations (p < 0.05). It was found that there were no significant differences between Epiphany-Resilon combination and all the other groups (p > 0.05).