Distolingual root prevalence in mandibular first molar and complex root canal morphology in incisors: a CBCT analysis in Indian population.

Cone-beam computed tomography was used to understand the possible correlation between the prevalence of distolingual root (DLR) in permanent mandibular first molars (MFMs) and the associated complicated mandibular incisor's root canal morphology (MIs) in an Indian population. A total of 400 scans were evaluated for MFMs and MIs. The prevalence of DLRs and root canal anatomy of MIs were assessed based on Vertucci's classification, and then the sample were grouped according to age, sex and side. Statistical analysis was used to evaluate the possible correlation between the presence of DLRs in the first molar and root canal morphology of incisors. Chi square test was used to evaluate the correlation between the root canal configurations of MIs with the existence of DLRs in MFMs. There was no statistically significant difference between sexes or ages for the prevalence of DLRs in the first molars (p > 0.05), which was 6.62%, with the right side having a greater frequency of DLRs (7.8%) than the left (5.5%). Vertucci Type I canal configuration was most common for the mandibular central (66.75%) and lateral incisors (58.62%). Vertucci Type III was the most common complicated canal morphology, followed by Types V, II, and IV for MIs, with no statistically significant difference in the studied sample's age and sex. (p < 0.05). No association was observed between the presence of DLRs in first molars and complicated root canal configurations in MIs. Taken together, the possibility of complicated root canal configuration in MIs was lesser in the presence of DLRs in MFMs among the Indian population.

Low Prevalence of Amalgam-Associated Lichenoid Lesions in the Oral Cavity: A Prospective Study.

INTRODUCTION: Amalgam has been the restoration of choice for years, but its popularity has declined due to concerns about aesthetics, mercury toxicity and lichenoid lesions associated with it. Lichenoid reaction is considered to be a delayed hypersensitivity type of reaction and it has been associated with dental materials in general and amalgam in particular. MATERIALS AND METHODOLOGY: Two thousand patients having at least one amalgam restoration were examined for signs of lichenoid lesions when visiting the OPD of Conservative Dentistry and Endodontics at the Nair Hospital Dental College in Mumbai, India. Indirect spatial correlation to the amalgam restoration and the same were recorded. Descriptive analysis was used. RESULTS: Three (0.15%) out of 2000 patients with amalgam-associated lichenoid lesions showed complete resolution of lesions after the replacement of the restorations. CONCLUSION: Amalgam associated lichenoid lesions have a low prevalence and should not be a contraindication to its use in routine restorative dental practice. Patch tests and biopsies have questionable diagnostic and prognostic value. Identification of the lesions should be made after the elimination of all other causative factors for the presenting symptoms. A close spatial association of the lesion to amalgam and the regression of symptoms after its removal should be considered as confirming the diagnosis.

The precision of case difficulty and referral decisions: an innovative automated approach.

OBJECTIVES: Endodontic treatment works as a successful treatment modality in several cases. However, it may fail due to some reasons unforeseeable by the dentist. Many failures can be prevented by carefully assessing the difficulty level of the case before initiating treatment or by referral to a specialist. This study presents an approach using machine learning to generate an algorithm which can help predict the difficulty level of the case and decide about a referral, with the help of the standard American Association of Endodontists (AAE) Endodontic Case Difficulty Assessment Form. MATERIALS AND METHODS: Using the AAE Endodontic Case Difficulty Form after obtaining the patients' consent, 500 potential root canal patients were diagnosed. The filled forms were assessed by two pre-calibrated endodontists, and, in cases of conflicting opinion, a third endodontist's opinion was taken. Artificial neural network was used for generating the algorithm. RESULTS: Using 500 filled AAE forms, a sensitivity of 94.96% was achieved by the machine learning algorithm. CONCLUSION: This study provides an option for automation to the conventional method of predicting the difficulty level of a case, thus increasing the speed of decision-making and referrals if necessary. CLINICAL RELEVANCE: An AAE Endodontic Case Difficulty Assessment Form when utilized along with machine learning can assist general dentists in rapid assessment of the case difficulty. This is a helpful tool in developing countries, where endodontic treatment and referral guidelines are often neglected. It also helps to make difficulty level assessments easier for novice practitioners, when they are in doubt about the same.

Development and validation of an HPLC-UV method for analysis of methylphenidate hydrochloride and loxapine succinate in an activated carbon disposal system / 药物分析学报

Unused medications have the possibility of being abused, causing serious harm to individuals who were not prescribed the drug. The Food and Drug Administration (FDA) recommends the proper disposal of unused prescribed medications to maintain safety and prevent environmental hazards. However, many of the current disposal techniques do not properly address safety. A drug disposal pouch containing granular activated carbon offers a unique disposal method to deactivate residual or expiredmedication in a convenient, effective, and safe manner. A robust and validated method for methylphenidate hydrochloride and loxapine succinate was developed using high-performance liquid chromatography (HPLC) and the deactivation efficiency of the disposal system was tested. Methylphenidate hydrochloride was analyzed on a C18 analytical column (250mm × 4.60mm, 100?) using acetonitrile-water (0.05％ (v/v) trifluoroacetic acid) as the mobile phase at a flow rate of 1.0mL/min with a run time of 15min and retention time of 7.8min. Loxapine succinate was separated on a C8100? (250 mm × 4.6 mm, 5 μm) column maintained at 25 °C using a flow rate of 1.0mL/min. The run time was 10min and the retention time of the drug was around 4.6min.Mobile phase was composed of acetonitrile and water (0.3％ triethylamine) at pH 3.0 as 40:60 (v/v). Reference standard solutions (100 μg/mL) for both drugs were prepared by dissolving in mobile phases. These methods provide good linearity (R2 = 0.999) over the range of 5–100 μg/mL for methylphenidate hydrochloride and 0.1–100 μg/mL for loxapine succinate. The assay methods were successfully applied to study the deactivation of these drugs.

A Cone Beam Computed Tomography (CBCT) evaluation of MB2 canals in endodontically treated permanent maxillary molars. A retrospective study in Indian population.

BACKGROUND: Current technological advances have allowed application of different study designs and techniques for investigation of dental anatomy. Some clinical studies have provided evidence that Cone Beam computed tomography (CBCT) scanning is an important resource in assessment of root canal systems notably to identify MB2 canals in maxillary molars as CBCT scans allow in vivo dental investigation in axial, sagittal and coronal planes simultaneously. The current study was undertaken to detect and evaluate filled/unfilled MB2 canals in endodontically treated, asymptomatic maxillary molars utilizing cone beam computed tomography (CBCT). MATERIAL AND METHODS: A retrospective study of 100 CBCTs of patients were underwent scanning for various treatment modalities, with asymptomatic endodontically treated permanent first and second maxillary molars were selected. History of root canal treatment varied from minimum of 1 year to a maximum of 10 years. Axial and paraxial images obtained were used to assess the presence of MB2 canal. Paraxial images were used to assess the periapical status. RESULTS: Of the 100 scans, 66 were of permanent maxillary first molar and 34 were of permanent maxillary second molar. The incidence of MB2 canal was 86.36% in maxillary first molars and 29.4% in maxillary second molars. 77.19 % of maxillary first molars and 90% of maxillary second molars had an unfilled MB2 canal. 72.7% of maxillary first molars and 88.8% of maxillary second molars showed significant periapical radiolucencies in unfilled MB2 canals. CONCLUSIONS: MB2 canals were present in majority of cases and most of the unfilled MB2 canals showed evidence of periapical radiolucencies. Key words:MB2 Canals, Cone Beam computed Tomography (CBCT), Filled /Unfilled canals, Endodontically treated teeth.