Micro-CT evaluation of four final irrigation protocols on hard-tissue debris removal from mesial roots of mandibular molars containing isthmus.

OBJECTIVES: To evaluate by means of microcomputed tomography (micro-CT), the efficacy of four final irrigation protocols in the removal of hard-tissue debris (HTD) in mesial roots of mandibular molars containing isthmus. MATERIALS AND METHODS: Forty standardized mesial roots of extracted mandibular molars presenting isthmus were selected. The root canals were prepared and randomly divided into 4 groups (n = 10): EA, EndoActivator (Dentsply Sirona); EC, Easy Clean (Easy Dental Equipment, Belo Horizonte, Brazil); XPF, XP-Endo Finisher (FKG Dentaire, La Chaus-de Fonds, Switzerland); and PUI, passive ultrasonic irrigation using Irrisafe tip (Satelec Acteon, Merignac, France). Each final irrigation protocol was performed in two cycles (60 s), using, respectively, 2.5% sodium hypochlorite and 17% EDTA. Micro-CT scans were obtained pre-operatory, post-preparation, and post-irrigation. The percentage of HTD reduction was calculated. Data was analyzed statistically (ANOVA and Kruskal-Wallis, significance set at 5%). RESULTS: The percentage of HTD reduction was greatest for the XPF group (77.92%), followed by EA (62.92%), PUI (47.48%), and EC (32.65%). Statistical differences (p < .05) were found between XPF and EC only. A significant difference (p < .05) was found between XPF and EC in all thirds and between PUI and EC in the middle third. CONCLUSIONS: XPF, EA, and PUI were similarly effective in HTD reduction. However, none of the evaluated protocols was able to completely remove all the debris. CLINICAL RELEVANCE: Final irrigation protocols aim to clean the canal complexities that are not addressed by the shaping procedures. Micro-CT allowed to assess the removal of hard-tissue debris in the isthmus and canals of mandibular molars.

Higher Speed and No Glide Path: A New Protocol to Increase the Efficiency of XP Shaper in Curved Canals-An In Vitro Study.

INTRODUCTION: This in vitro study compared the performance of the XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland) in curved canals when used with a higher speed (3000 rpm) without a glide path with the manufacturer's protocol. METHODS: Twenty extracted mandibular molars with separate mesial curved canals were matched to obtain 2 standardized groups (n = 20). For the XP 1000 group, a glide path up to a size 15 hand file was performed followed by rotary instrumentation with the XP shaper at 1000 rpm, following the manufacturer's recommendations. For the canals in the XP 3000 group, the file was rotated at 3000 rpm after only negotiation the canal with a size 8 hand file (patency file). The operating time and the number of strokes taken to reach the working length (WL) and fit a 30/.04 gutta-percha cone to the WL were recorded. The shaping abilities were evaluated by micro-computed tomographic imaging and file deformation by scanning electron microscopy. Data were analyzed using analysis of variance and chi-square tests at a 5% significance level. RESULTS: The XP 3000 group required less time and strokes to reach the WL (P < .05) and resulted in a higher percentage of adequate cone fit (P < .05). No difference was found between groups regarding the micro-CT parameters, except for the taper, which was larger in the XP 3000 group in the apical and middle thirds (P < .05). No difference was found regarding file deformation between the 2 groups. CONCLUSIONS: The suggested protocol for the use of the XP (3000 rpm without a glide path) appears to be more efficient than the manufacturer's recommended protocol to prepare curved canals in vitro.

Detection of Tooth Color Before and After Bleaching Using an Electronic Device.

The purpose of this article is to present a new computerized technique for evaluating tooth color before and after internal bleaching. Internal bleaching is a common and relatively safe procedure, from which results can be easily evaluated by both the dentist and the patient. Clinically, evaluation of the tooth color before, during and after internal bleaching is usually completed by using a color scale and comparing the shade to that of the tooth. However, since in some cases the bleaching results are not obvious, this method has limited value for complicated cases and especially for dental research. The case presented here demonstrates the digital color evaluation process of a tooth going through all phases of internal bleaching. The detected color is presented as the color scale numbers and can easily be saved for follow-up. Those results are presented on the device screen for the all-labial surface and also separately for the incisal, middle and cervical areas. This digital method for color detection can easily be used at every dental clinic as a validated dental record for the bleaching process. This method can also be used for dental research that evaluates the efficacy of bleaching techniques. The esthetic results can be verified easily and precisely.

A Multidisciplinary Approach for Managing Severely Malaligned Lower Molars.

An impacted mandibular molar is a common clinical situation that may damage adjacent teeth and impair periodontal health. Improper treatment brings the risk of damaging adjacent vital tissues. The risk can be reduced by early diagnosis and extraction of the impacted tooth by an experienced clinician. However, in clinical cases of two impacted molars, it may be beneficial for the patient to save at least one molar. This can be achieved by orthodontic alignment of one of the molars, while extracting the other. The decision should be based upon prognosis and risks for each procedure and for both teeth. The case presented here demonstrates a recommended clinical decision-making process before treatment, followed by monitored multidisciplinary treatment with adaptations made as the treatment progresses.

Fractured Endodontic Instrument: A Clinical Dilemma Retrieve, Bypass or Entomb?

A common clinical complication of root canal treatment is fracture of an endodontic file. The risk of treatment failure because of incomplete cleaning and shaping encourages the dentist to retrieve the fractured part. Several techniques have been offered to remove the fractured file, yet those techniques sacrifice sound dentin, which may lead to increased risk for perforations and root fractures. The aim of this article is to describe a clinical approach to accessing fractured files, depending on their location in the canal and stage of cleaning and shaping. This prudent approach may decrease complications from unnecessary dentin removal, while respecting the biological aspects of cleaning the canals.

Extranodal large B cell lymphoma of the anterior maxilla. Case report and review of literature.

In the oral cavity, lymphoproliferative disorders can manifest in various ways, often as an extranodal externalization. In the case presented here, it was a B cell lymphoma originating in the periapical bone of the anterior maxilla. X-ray revealed a periapical radiolucency associated with an intact tooth with no decay, fillings or history of trauma. The tooth tested non-vital. After root canal treatment, an apicoectomy was performed with a biopsy. The most common diagnosis would be of dental etiology. The pathology report revealed a non-Hodgkin's B cell lymphoma. Most often, this disease appears as localized dental or oral pathology. Non-specific signs and symptoms present in association with lymphoproliferative disorders include lymphadenopathy, trismus, pain, swelling, sinusitis, fever, sepsis, prosthetic instability and paresthesia. Early detection results in decreased morbidity and a better prognosis for the patient.

Fractured endodontic instrument: a clinical dilemma. Retrieve, bypass or entomb?

A common clinical complication of root canal treatment is fracture of an endodontic file. The risk of treatment failure because of incomplete cleaning and shaping encourages the dentist to retrieve the fractured part. Several techniques have been offered to remove the fractured file, yet those techniques sacrifice sound dentin, which may lead to increased risk for perforations and root fractures. The aim of this article is to describe a clinical approach to accessing fractured files, depending on their location in the canal and stage of cleaning and shaping. This prudent approach may decrease complications from unnecessary dentin removal, while respecting the biological aspects of cleaning the canals.