Mete Ungor

The Effect of Two Different Root Canal Sealers and Smear Layer on Resistance to Root Fracture

The purpose of this in vitro study was to test the effect of Ketac-Endo (KE) and AH 26 on resistance to root fracture and also to evaluate the effect of smear layer. Seventy-two human maxillary canine teeth were randomly divided into six groups (n = 12) and were prepared using six different methods: group 1: KE, without smear layer (smear -); group 2: KE, with smear layer (smear +); group 3: AH 26, smear (-); group 4: AH 26, smear (+); group 5 (negative control): nonprepared; group 6 (positive control): prepared but unfilled. After storing 1 week in 100% humidity at 37 degrees C, the coronal lingual walls and root canal spaces were lowered 2 mm below the buccal walls of the roots. The samples were placed into acrylic resin blocks so that 10 mm of buccal roots were exposed and were placed in a specially designed steel pad at an angle of 15 degrees to the long axis of the root. A slowly increasing force was applied at the junction of the buccal wall and root canal space until fracture occurred. The force required to fracture each tooth was recorded as kg and statistically analyzed using one-way analysis of variance and Duncan tests. The results indicated that instrumentation of the root canals significantly weakened the tooth structure to fracture (p < 0.05). The canals obturated with either sealer were significantly stronger than roots whose canals were instrumented but not obturated (p < 0.05), and there was no difference between the sealers. The presence or absence of the smear layer did not cause any significant effect on the root fracture resistance of the teeth (p > 0.05).

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.

Intentional re‐plantation of a vertically fractured tooth repaired with an adhesive resin

AIM To present the successful treatment of a vertically fractured tooth by intentional re-plantation after root canal treatment and repair with an adhesive resin. SUMMARY Vertical root fracture is a challenging problem in respect of diagnosis and management options. In this case, a vertically fractured maxillary premolar was treated by intentional re-plantation after repairing it with 4-Methacryloxyethyl trimellitate anhyride/methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin cement. At the 36-month follow-up, the tooth was asymptomatic, radiographically sound with reduced deep periodontal pockets and vertical bone loss. KEY LEARNING POINTS • Intentional replantation after repairing fractured fragments with an adhesive resin extraorally is a treatment option. • Long-term follow-up is necessary to evaluate the outcome of this technique.

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.

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.

Multidisciplinary approach to traumatized teeth: a case report.

Treatment of crown fractures often requires a multidisciplinary approach. In the anterior teeth, reestablishment of proper esthetics and function is quite important for the patient. However, crown-root fractures with fracture line below the gingival attachment or alveolar bone crest presents restorative difficulties. This case report presents a cervical tooth fracture that had been treated with minimal invasive approach with different disciplines. The tooth had endodontic treatment and a glass-fiber post, and a composite core was accomplished. Then, the tooth was extruded to the desired level with orthodontic forced eruption before definitive restoration.

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

BackgroundTo 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.MethodsRecords 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.ResultsThe 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.ConclusionsThe 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.

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.

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.

Odontogenic effects of two calcium silicate-based biomaterialsin 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 Dulbeccos Modified Eagles 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.