Active Bacteria in Carious Dentin of Mandibular Molars with Different Pulp Conditions: An In Vivo Study.

INTRODUCTION: This study evaluated the relative abundance and ribosomal activity of selected bacteria in carious dentin of teeth with different pulp conditions. METHODS: Thirty healthy patients with class I occlusal caries in molars were categorized into 3 groups based on the pulp diagnosis: normal pulp (NP, n = 10) with caries extending less than half the thickness of dentin (as assessed radiographically), reversible pulpitis (n = 10), and symptomatic irreversible pulpitis (n = 10) with caries extending more than two thirds of the thickness of dentin. Carious dentin samples were collected from the deepest part of the cavity and stored in RNAlater solution (Ambion Inc, Austin, TX). Eight bacterial taxa were evaluated from the samples: Streptococcus mutans, Lactobacillus fermentum, Veillonella, Actinomyces, Rothia dentocariosa, Olsenella profusa, Prevotella intermedia, and Bifidobacterium dentium. The 16S ribosomal RNA (rRNA) gene and 16S rRNA were quantified by real-time polymerase chain reaction and used to calculate the relative genome abundance and relative ribosomal abundance. The Fisher exact test was used to compare proportions between groups. The mean rank difference between the various groups was assessed using the Kruskal-Wallis test with the Bonferroni-Holm correction. RESULTS: The reversible pulpitis group had significantly higher 16S rRNA gene and rRNA counts of Actinomyces (P < .001 and P = .002) and B. dentium (P = .005 and P = .007) relative to the NP group. The symptomatic irreversible pulpitis group had significantly higher 16S rRNA gene and rRNA counts of L. fermentum (P < .001 and P < .001), Actinomyces (P < .001 and P < .001), O. profusa (P < .001 and P < .001), P. intermedia (P = .001 and P = .002), and Bifidobacterium (P < .001 and P < .001) relative to the NP group. CONCLUSIONS: Specific bacterial activity varies in carious dentin of teeth with different pulp conditions.

The time taken for retrieval of separated instrument and the change in root canal volume after two different techniques using CBCT: An in-vitro study.

Introduction: Retrieval of separated instrument from a root canal may lead to increased dentin loss and prolonged treatment time. Aim: The aim of this study was to evaluate the retrieval time and increase in root canal volume after instrument retrieval with two retrieval techniques under dental operating microscope. Materials and Methods: Forty extracted human mandibular molars with 30°-40° mesiobuccal root canal curvature were selected based on cone-beam computed tomography (CBCT) and divided into two groups (n = 20 each). Group 1: Terauchi group (Terauchi ultrasonic tips) and Group 2: Satelec group (Satelec ET25 ultrasonic tip) based on the retrieval technique. Groups 1 and 2 were further divided into two subgroups (n = 10 each) based on the size of the separated instrument; Groups 1a and 2a with ProTaper Gold (PTG) F1 and Groups 1b and 2b with PTG F2. The time taken for retrieval was calculated and increase in root canal volume was evaluated using CBCT. Results were statistically analysed with paired t-test and post hoc analysis by Tukey's HSD test. Results: All separated instruments were successfully retrieved. The mean time for instrument retrieval was lower in Terauchi group than in the Satelec group (P > 0.05) but not significantly. The mean increase in total root canal volume post-retrieval as well as the mean volume corresponding to the coronal part of the separated instrument was significantly lower in Terauchi group than in Satelec group (P < 0.05). Conclusion: Terauchi ultrasonic instruments resulted in reduced instrument retrieval time with lower loss of root dentin.

Coronal Bacterial Penetration after 7 days in class II endodontic access cavities restored with two temporary restorations: A Randomised Clinical Trial.

The aim of this in vivo randomised clinical trial was to assess coronal bacterial penetration after placement of Cavit G and IRM temporary restorations in Class II endodontic access cavities. After completion of endodontic treatment, placement of an orifice seal and disinfection of the operating field, sterile cotton pellets were placed in the pulp chamber and the cavities were restored with Cavit G or IRM. After 7 days, coronal and proximal restoration thickness was measured by digital radiographs. Cotton pellet was evaluated by culture methods and polymerase chain reaction assay and bacterial species identified. Bacterial growth was observed in 5 of the 27 (18%) Cavit G samples and in 11 of the 27 (40%) IRM samples which was not significant. Coronal restoration thickness of 4-5 mm and proximal restoration thickness of more than 2.15 mm for Cavit G and 2.35 mm for IRM are recommended to prevent bacterial penetration over 7 days. Adequate restoration thickness is critical to prevent bacterial penetration.

Endodontic management of a hypertaurodontic tooth associated with 48, XXYY syndrome: A review and case report.

Taurodontism is a developmental anomaly of a tooth characterized by large pulp chamber and short roots. Patients with multiple taurodontic teeth are associated with the probability of a systemic syndrome or chromosomal anomaly. This is the first reported incidence of the endodontic management of a hyper taurodontic mandibular second molar in a patient diagnosed with 48, XXYY syndrome.