Use of rubber dams during root canal treatment in Taiwan.

BACKGROUND/PURPOSE: Isolation of teeth with rubber dams is an important procedure for infection control in dentistry, especially in endodontic treatment. This study surveyed the prevalence of rubber dam usage in nonsurgical root canal treatment (RCT) by dentists under the National Health Insurance system in Taiwan. METHODS: A total of 1,332 completed RCT cases were randomly selected from a large database from the Bureau of National Health Insurance in Taiwan in 2004. The radiographs and dental charts of the selected cases were evaluated for the prevalence of rubber dam usage in RCT. The frequencies of rubber dam usage for RCT by dentists were compared between hospitals and private dental clinics and among six different regions in Taiwan. RESULTS: The overall prevalence of rubber dam usage for RCT by dentists under the National Health Insurance system in Taiwan was 16.5%. The frequency of rubber dam usage for RCT by dentists in hospitals (32.8%) was significantly higher than that (10.3%) in private dental clinics (p < 0.0001). However, there was no significant difference in the frequency of rubber dam usage for RCT by dentists among six different geographic regions in Taiwan. CONCLUSION: The prevalence of rubber dam usage for RCT by dentists in Taiwan is relatively low. Because rubber dam isolation of an endodontically-treated tooth can provide better infection control, increase patient protection, and improve treatment efficiency, there is an urgent need to advise dentists in Taiwan to use rubber dams for every RCT case.

The morphologic characteristics of the distolingual roots of mandibular first molars in a Taiwanese population.

INTRODUCTION: The prevalence of extra distolingual (DL) roots in mandibular first molars in Chinese population is about 20%. The purpose of this study was to evaluate the difference of root length and root curvatures between distobuccal (DB) and DL roots of three-rooted mandibular first molars in a Taiwanese (Chinese) population. METHODS: Of the 293 extracted mandibular first molars, DL roots were present in 29 (9.9%) teeth. Excluding teeth with fractured DB or DL roots, 21 mandibular first molars were further investigated. DB and DL root lengths were measured from the lower level of furcation at the distal surface to the root apex. The curvature of the DL root was measured on mesial-distal and buccal-lingual radiographs by Schneider's technique. RESULTS: The DL roots were significantly (p < 0.001) shorter than the DB roots with an average of 1.48 +/- 0.81 mm. Most DL roots had a greater curvature in a buccal-lingual orientation (36.35 degrees +/- 9.38 degrees ) than a mesial-distal orientation (9.24 degrees +/- 6.10 degrees ) and 28.57% of the curved DL roots had the curvature at the apical one third (p < 0.001). CONCLUSION: The results of this study verified the characteristics of shorter root length and severe buccal-lingual inclination of DL roots in three-rooted mandibular first molars.

Eugenol suppressed the expression of lipopolysaccharide-induced proinflammatory mediators in human macrophages.

Eugenol is commonly used as an analgesic agent during acute pulpitis and is a major component of root canal sealers. Despite the frequent applications of eugenol in the practice of dentistry, little is known about the role of eugenol under the status of inflammation. This study was aimed to investigate the influence of eugenol on human macrophages (U937) under the stimulation of lipopolysaccharide (LPS). Eugenol was shown to block the release of the bone resorbing mediators, including interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and prostaglandin E2 from LPS-stimulated macrophages. In contrast, eugenol alone did not alter the expression levels of these proinflammatory mediators in macrophages. Consistent with downregulation of bone-resorbing mediators, eugenol suppressed the messenger RNA expression of LPS-induced IL-1beta, TNF-alpha, and cyclooxygenase-2 in macrophages. The results suggest a potential anti-inflammatory effect of eugenol in the acute inflamed pulps and apical periodontitis.

Complicated root canal morphology of mandibular first premolar in a Chinese population using the cross section method.

The purpose of this study was to assess the canal anatomy and morphology of mandibular first premolars in a Chinese population. Eighty-two extracted mandibular first premolars with intact roots were collected and stored in a glutaraldehyde solution. The teeth were embedded in clear resin and the root length was measured. The roots were resected perpendicular to the long axis at 3, 6, 9, and 12 mm from the apex. The resected root surfaces were polished, rinsed, dried, and stained with methylene blue. Digital photographs of the cross-sectional root surfaces were made at 24X. The incidence of multiple canals and varied morphology was determined by two independent examiners. The results indicated that 54% of the mandibular first premolars demonstrated a single canal. Twenty-two percent contained two canals and 18% percent had C-shaped configuration. The C-shaped root canal occurred predominantly in the 3 and 6 mm sections with one or two canals coronally. A unique finding was the circumferential canal (apical delta), which was characterized by a single canal splitting into 3 or 4 canals. The incidence of circumferential canal was 6% and occurred only in the apical 3 mm cross-sections. Identification of this unique apical canal configuration and the high incidence of multiple canals in mandibular first premolars may explain endodontic treatment failure in this tooth group.

Nonsurgical endodontic treatment of a two-rooted maxillary central incisor.

This case report presents an uncommon case of a two-rooted maxillary central incisor with a periapical radiolucent lesion. A 17-yr-old female patient was referred for dental consultation after a motorcycle accident. The maxillary left central incisor had a bifurcated root that was confirmed by radiographs taken at different angles. Nonsurgical endodontic therapy was performed. At the 1 yr recall examination, the tooth was asymptomatic and the radiograph showed that the periapical radiolucent lesion had healed.

Nonsurgical endodontic treatment of dens invaginatus with large periradicular lesion: a case report.

The endodontic treatment of teeth with severe Type 3 dens invaginatus, characterized by an infolding of enamel and dentin, extending deep into the pulp cavity near the root apex, may be complicated and challenging. Because of the bizarre root canal anatomy and widely open apex, a combination of nonsurgical and surgical endodontic treatment or extraction is the most common choice of therapy. This article describes a nonsurgical endodontic treatment of a tooth with severe Type 3 dens invaginatus and an associated large periradicular lesion. After complete removal of the invaginated central mass of hard tissue and long-term calcium hydroxide treatment, nonsurgical endodontic treatment was performed. Complete healing of the periradicular lesion was observed at 25-month and 74-month follow-up examinations.