Endodontic Management of a Maxillary First Molar with Taurodontia and Two Palatal Canals: A Case Report

The present case report describes an endodontic treatment of a three-rooted maxillary first molar with taurodontia and a palatal root with two separate canals. Maxillary first molar with two palatal canals is rare since extra canals are found most in the mesiobuccal root as the second mesiobuccal canal. Clinicians should have a thorough knowledge of the root canal system and internal anatomy and be alert about the possible existence of any variation in the canal morphology because it determines the successful outcome of an endodontic treatment

Effect of Intra-Canal Calcium Hydroxide Remnants on the Push-Out Bond Strength of Two Endodontic Sealers

Introduction: The aim of this study was to evaluate the effect of intra-canal calcium hydroxide (CH) remnants after ultrasonic irrigation and hand file removal on the push out bond strength of AH-26 and EndoSequence Bioceramic sealer (BC Sealer). Methods and Materials: A total of 102 single-rooted extracted human teeth were used in this study. After root canal preparation up to 35/0.04 Mtwo rotary file, all the specimens received CH dressing except for 34 specimens in the control group. After 1 week, the specimens with CH were divided into 2 groups (n=34) based on the CH removal technique; i.e. either with ultrasonic or with #35 hand file. Then specimens were divided into two subgroups according to the sealer used for root canal obturation: AH-26 or BC Sealer. After 7 days, 1 mm-thick disks were prepared from the middle portion of the specimens. The push out bond strength and failure mode were evaluated. Data were analyzed by the two-way ANOVA and Tukey’s post hoc tests. Results: The push out bond strength of both sealers was lower in specimens receiving CH. These values were significantly higher when CH was removed by ultrasonic (P<0.05). The dominant mode of failure in all subgroups was of mixed type except for the BC Sealer specimens undergoing CH removal with hand file which dominantly exhibited adhesive mode of failure. Conclusion: CH remnants had a negative effect on the push out bond strength of AH-26 and BC Sealer. Ultrasonic irrigation was more effective in removing CH.Keywords: AH-26; Calcium Hydroxide; Endosequence BC Sealer; Push-Out Bond Strengt

The Effect of Photobiomodulation on the Depth of Anesthesia During Endodontic Treatment of Teeth With Symptomatic Irreversible Pulpitis (Double Blind Randomized Clinical Trial)

Introduction: Achieving appropriate anesthesia in patients with symptomatic irreversible pulpitis in mandibular molars during endodontic treatment is always one of the most challenging aspects. Photobiomodulation (PBM) has been used in dentistry due to its anti-inflammatory properties and regenerative effects. This study evaluates the effects of PBM in the depth of anesthesia in inferior alveolar nerve block.Methods: In this randomized clinical trial, 44 patients requiring endodontic treatment in lower molar, left or right were selected, half of them were randomly treated with PBM therapy. Laser irradiation by 980 nm diode laser with a single dose (15 J/cm2, for 20 seconds) before anesthesia was performed at the buccal aspect. Inferior alveolar nerve block was performed once. Success was defined as no or mild pain (no need for any supplemental injection), based on the visual analogue scale during access cavity preparation. Results were evaluated using SPSS software.Results: The results of this study showed that the necessity for supplemental injection was lower in the group receiving laser than in the group without laser (P = 0.033). The mean pain intensity during dentin cutting was lower in the group receiving laser than in the group without laser (P = 0.031). Also, the mean pain intensity during pulp dropping was lower in the group receiving laser, than the group without laser (P = 0.021).Conclusion: Based on the results of this study, it seems that the application of PBM before anesthesia is effective on increasing depth of anesthesia

Retreatment of a 6-Canalled Mandibular First Molar with Four Mesial Canals: A Case Report

Successful root canal treatment requires adequate knowledge regarding morphologic variations in root canal system of teeth. This report describes a six-canalled mandibular first molar with four mesial root canals requiring endodontic retreatment. The two additional canals in the mesial root were found during retreatment with the aid of illumination and magnification. In conclusion, the possibility of atypical morphology and additional canals should never be over looked

Restoration of Endodontically Treated Anterior Teeth by Modified Conservative Endocrowns: A Case Report with a 30-Month Follow Up

Objectives Restoration of severely damaged endodontically treated anterior teeth typically poses a challenge. Specific indication of post-retained restorations in such teeth has reasonably been questioned because of the potential tooth structure weakening. The present study aimed to describe a modified conservative endocrown (modified refers to intracanal extension while conservative refers to preparation at the finish line) to rehabilitate severely damaged anterior teeth. Case: Endodontically treated lower right central incisor had inadequate remaining tooth structure and restored by endocrwn restoration as a definitive treatment and followed for 30 month. Conclusion Considering the clinical outcome after 30 months of follow-up, it seems that this specific type of endocrown could efficiently serve as a conservative treatment approach to restore endodontically treated anterior teeth

Mandibular Second Premolar with Four Canals: A Case Report: Root canal treatment considerations of mandibular second premolar with four canals

The mandibular second premolar can be considered one of the most challenging teeth to treat endodontically; due to the complexity of its root canal morphology and increased incidence of multiple canals. The knowledge of internal anatomy of root canals and their possible variations as well as use of magnification, e.g. operating microscope, radiographic examination and illumination, can increase the chances of finding additional canals and contribute to the success of endodontic treatment. The purpose of the current investigation is to report the successful endodontic treatment of a mandibular second premolar with 4 canals; all of them in one single root

Minimum Intracanal Dressing Time of Triple Antibiotic Paste to Eliminate Enterococcus Faecalis (ATCC 29212) and Determination of Minimum Inhibitory Concentration and Minimum Bactericidal Concentration: An Ex Vivo Study

Objectives: Enterococcus faecalis (E. faecalis) is the most commonly isolated microorganism from teeth with postoperative infection. Triple antibiotic paste (TAP) has the ability to eradicate microorganisms from the root canal system when used as an intracanal medicament. The aim of this study was to determine the minimum duration of application of TAP required for elimination of E. faecalis from the root canal system and its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in an ex-vivo model. Materials and Methods: Root canals of 34 extracted human single canal teeth were inoculated with E. Faecalis after instrumentation, and then 4 g of TAP (ciprofloxacin, metronidazole and doxycycline) was mixed with 4.5 mL of saline and applied as intracanal medicament. The teeth were sectioned longitudinally and dentin chips were collected and evaluated to determine the count of bacterial colonies. Micro-dilution broth test was used to assess the MIC and MBC of TAP. Data were analyzed using SPSS version 22 via the Wilcoxon signed rank test. Results: After seven days of application of TAP as intracanal medicament, E. faecalis was eliminated from the dentinal tubules of the apical half of root canal up to 400 µ depth. The MIC and MBC of TAP in its original concentration were both found to be 16 µg/mL.   Conclusions: The original concentration of TAP was found to be 5×104 times its MIC. Considering the risk of coronal discoloration of teeth following the use of TAP, application of its lower concentrations is recommended

Conservative management of an advanced external cervical resorption with internal approach using bio‐ceramic materials: A case report

Key clinical message A successful management of an advanced external cervical resorption using a conservative approach with CBCT, dental operating microscope, and a new bio‐ceramic material. Abstract External cervical resorption (ECR) is a pathologic condition that is initiated on the external aspect of the root, below the epithelial attachment in the cervical position. This article will report a case of external cervical resorption (ESR) in an advanced stage, which was asymptomatic and was incidentally detected in a follow‐up radiograph after the end of orthodontic treatment. Cone‐beam computed tomography (CBCT) was prescribed to accurately diagnose the resorptive lesion and differentiate it from internal root resorption (IRR), and the final diagnosis was Heithersay's class IV ECR. Considering the health of the periodontium and the absence of attachment loss, it was decided to use a conservative internal approach to the management of this case. After the treatment, the patient was asymptomatic and the radiographic examinations showed no signs of peri‐radicular pathology during the follow‐up period. With the correct case selection and the availability of the appropriate materials and equipment such as a dental operating microscope (DOM) and bio‐ceramic materials, the internal approach can be a successful and minimally invasive treatment, even for the management of advanced ECR cases

Effect of Trenched Zirconia Bar on Flexural Strength of IPS-Empress 2 Ceramic

Background and Aim : In the recent years, inlay-retained fixed partial dentures(FPDs)have gained attention due to the preservation of tooth structure and their conservative tooth preparation. The wettability of IPS2 ceramic surfaces can be increased by acid etching enhancingtheir bond to resin cement. High-strength ceramics cannot be etched due to the high resistance of alumina and zirconia. Inadequate bond between the zirconia and resin cement in zirconia-based FPDs leads to unequal stress distribution on the surface and consequent debonding and failure of the inlay-retainer. This study aimed to evaluate the effect of a trenched zirconia bar on the flexural strength of IPS-Empress 2 ceramic core .   Materials and Methods : In this experimental study, 21 ceramic specimens measuring 3x4x25 mm were divided into three groups:   Group 1 was the control group and fabricated from In-Ceram alumina ceramic   Group 2 specimens were fabricated from IPS-Empress 2 ceramic   Group 3 specimens were fabricated from IPS-Empress 2 and had an embeddedtrenched zirconia bar at the bottom   Specimens were subjected to three point flexural test with 15 mm support span at a cross head speed of 0.5 mm/min. The fracture forces were recorded and data were statistically analyzed using ANOVA and Tukey’s test. The fracture surfaces were evaluated with an electron microscope .   Results: The flexural strength of specimens was 302.66 in group 1, 187.25 in group 2 and 247.89 MPa in group 3. Flexural strength of In-Ceram specimens was significantly higher than that of IPS2 (P<0.019) but no difference existed between In-Ceram and IPS2 with an embeddedtrenched zirconia bar. Therefore, use of trenched zirconia bar at the bottom of specimens had limited effects on increasing their flexural strength ).   Conclusion : Flexural strength of IPS-Empress 2 specimenswith an embeddedtrenched zirconia bar was equal to that of the other two groups. Although the flexural strength value of the mentioned group was higher than that of IPS-Empress 2 specimens without the bar and lower than that of In-Ceram alumina specimens, these differences were not statistically significant

Longevity of Amalgam Build-Up Restorations in Endodontically Treated Teeth

Background and Aim: Restoration of endodontically treated teeth is one of the most important and challenging topics in restorative dentistry. Longevity of such restorations is an essential factor in treatment planning. Amalgam build-up is a conservative method for restoration of endodontically treated teeth. Therefore, this study aimed to assess the longevity of this type of restoration in endodontically treated molar teeth. Materials and Methods: In this retrospective study, 110 endodontically treated molar teeth of 98 patients that had received amalgam build-up restorations with at least one cusp coverage with 3-10 years of longevity were evaluated. The restorations included mesio-occluso-distal (MOD;40%), disto-occlusal (DO;23%), mesio-occlusal (MO;17%) and complex amalgam restorations (20%). Binary logistic regression and Kaplan-Meier tests were used for statistical analysis. Results: Of all restorations, cracks were observed in 22.7% of restorative materials and 10.9% of teeth. Secondary caries was found in 29% of the teeth. Based on binary lo-gistic regression, MOD restorations had significantly higher rate of marginal fracture and recurrent caries (P<0.05). Teeth with one or four built-up cusps were significantly more resistant to fracture compared to other groups. Patients, who regularly used dental floss had significantly lower rate of secondary caries and restoration fracture (P=0.032). Conclusion: The average longevity of amalgam build-up restorations was 8.45 years, which is comparable to minimum longevity of casting restorations. Thus, amalgam restorations seem to be an acceptable conservative method for restoration of endodontically treated teeth