METHODS: 75 human mandibular molars were randomly divided into five equal groups. Teeth were standardized, endodontically-treated and restored according the assigned group as follows: amalgam core only, prefabricated titanium post in the distal canal and amalgam core, composite core only; fiber post in the distal canal and composite core. One group of untreated sound teeth was used as a control. Non-precious metal crowns were fabricated and cemented on the prepared specimens with Rely X U200 resin cement. All specimens were subjected to a compressive load at crosshead speed 0.5 mm/minute, 25° to the long axis of the tooth. Failure loads and modes were recorded.
RESULTS: Mean failure loads among the groups were significantly different (P= 0.035). Post-hoc multiple pair-wise comparisons revealed the amalgam core and composite core groups produced significantly lower fracture resistance than the control group (P= 0.041 and P= 0.025, respectively) and no significant differences among the different intra-radicular techniques (P> 0.05). The composite core with fiber post and amalgam core with titanium posts showed the highest percentage of favorable failures (67%) and non-favorable failures (87%) respectively.
CLINICAL SIGNIFICANCE: The composite core with fiber post is the most appropriate intraradicular restoration in cases of severely compromised molars.
DESIGN: Dental pulp from extracted human permanent teeth was processed for fluorescence immunohistochemistry. Ten asymptomatic (normal) and 10 symptomatic (symptoms associated with pulpitis) teeth were used in this study. Nerve fibers were identified by immunostaining for a marker, protein gene product 9.5, and the cells were counterstained with 4',6-diamidino-2-phenylindole. An anti-TRPV4 antibody was used to trace TRPV4 expression.
RESULTS: TRPV4 expression was co-localized with the nerve fiber marker. Immunoreactivity for TRPV4 was more intense (p
METHODS: Sixty-five subjects who voluntarily discontinued therapy were recalled. The subjects' demographic data and dental history since discontinuation of periodontal treatment were collected via questionnaires. The subjects' periodontal condition, radiographic data and individual tooth-based prognosis at pre-discontinuation and recall were compared.
RESULTS: A total of 229 teeth had been lost over time, mainly due to periodontal reasons. Upper and lower molars were most frequently lost. Rate of tooth loss (0.38/patient per year) was comparable to untreated patients. Deterioration in periodontal health in terms of increased percentage of sites with bleeding on probing (BOP) and sites with probing pocket depths (PPD) of 6 mm or more at re-examination was observed. Positive correlations were found between tooth loss and: (i) years since therapy discontinued; (ii) percentage of sites with PPD of 6 mm or more at pre-discontinuation; and (iii) at re-examination. Percentage of sites with PPD of 6 mm or more at recall was positively correlated with periodontal tooth loss and negatively correlated with percentage of sites without BOP.
CONCLUSIONS: Patients not completing a course of periodontal therapy are at risk of further tooth loss and deterioration in periodontal conditions over time.