Technical quality of root canal treatment in Taiwan.

AIM: To evaluate the current technical quality of root canal treatment (RCT) in Taiwan. METHODOLOGY: A total of 1085 RCT cases, randomly selected from a large sample and representative of the Taiwanese population from April to September 2000, were evaluated by eight endodontic specialists. The qualitative evaluation of RCT cases was based on two variables: length of the root filling and density of the obturation. A root canal with both adequate filling length (the apical termination of the root filling within 2 mm of the radiographic apex) and complete obturation (no lateral or apical canal lumen visible in the apical one-third of the root canal) was defined as having good-quality endodontic work (GQEW). A tooth was defined as having a GQEW when all its canals were categorized as GQEW. RESULTS: From a total of 1867 root canals, overfilling occurred in 235 (12.6%), adequate filling length in 1152 (61.7%), underfilling in 466 (25.0%) and no filling in 12 (0.6%). Of the 1867 root canals, 710 (38.0%) demonstrated complete obturation and 1157 (62%) demonstrated incomplete obturation. GQEW was found in 650 (34.8%) root canals and 329 (30.3%) teeth. The percentage of teeth with GQEW in hospital cases (38.1%) was significantly greater (P < 0.001) than that in private clinic cases (24.3%). In addition, the frequency of teeth with GQEW in the anterior teeth (40.4%) or in the premolars (33%) was significantly greater (P < 0.001) than that in the molars (18.4%). CONCLUSIONS: Approximately 70% of the teeth receiving RCT in Taiwan were either of inadequate filling length or sealing density.

Microleakage between endodontic temporary restorative materials placed at different times.

Occlusal endodontic access preparations are occasionally made in teeth without removing the original restoration. However, microleakage between restorative materials that are placed at different times has not been extensively studied. Therefore, our objective was to compare microleakage at three areas: between an access opening restorative material and the cavity wall; between an additional material placed later to patch a secondary opening in the first restorative material and the original restorative material itself; and between the secondarily placed material and the cavity wall. Standard endodontic access preparations were made in 120 noncarious, nonrestored crowns of extracted human molars. These teeth were divided into six experimental groups. Another four molars were controls. The endodontic access cavities were restored with either IRM or amalgam as the primary restorative material. After 14 days, half of the primary restorations was removed, and this defect was filled with a secondary restorative material: IRM, Caviton, or a double seal of Caviton and IRM. Microleakage was measured linearly as the extent of basic fuchsin dye penetration under a stereomicroscope after thermal cycling (5 degrees and 55 degrees C for 100 cycles) and tooth sectioning. Wilcoxon signed-rank test was used for statistical analysis. Results indicated significantly less microleakage between primary and secondary restorative materials placed at different times than microleakage between primary temporary restorative materials and the access cavity wall, regardless of the type of primary restorative material used (IRM or amalgam).

Oral manifestations of human immunodeficiency virus-infected patients in Taiwan.

To understand the characteristic clinical features of human immunodeficiency virus (HIV)-related oral lesions and determine the prevalence of various oral lesions in HIV-infected patients in Taiwan, we conducted a cross-sectional study of 207 HIV-infected patients at the Taipei Municipal Institute for Venereal Disease Control. Overall, 108 (52.2%) patients had at least one oral lesion. The most common oral manifestation of HIV infection among these 207 patients was oral hairy leukoplakia (OHL, 29.5%), followed by candidiasis (12.1%), xerostomia (10.6%), aphthous ulcers (8.7%), and linear gingival erythema (5.8%). Less frequently encountered oral lesions included leukoplakia (1.9%), papilloma (1.4%), necrotizing ulcerative periodontitis (1.0%), Kaposi's sarcoma (1.0%), herpes simplex (0.5%), Burkitt's lymphoma (0.5%), and parotid gland enlargement (0.5%). Thirty-one (15%) patients had multiple oral lesions. Patients with oral candidiasis or multiple oral lesions had significantly lower mean CD4 lymphocyte counts and CD4/CD8 lymphocyte ratios than those without any oral lesions (p < 0.05). Chi-square analysis revealed that patients with CD4 lymphocyte counts below 200 cells/mm3 were more prone to have OHL (p < 0.002), oral candidiasis (p < 0.001) and multiple oral lesions (p < 0.001). Those with CD4/CD8 lymphocyte ratios below 0.4 were more likely to have OHL (p < 0.02), oral candidiasis (p < 0.01) and multiple oral lesions (p < 0.02) than those with higher counts. In conclusion, the occurrence of oral lesions, especially OHL and oral candidiasis, is fairly common in Taiwanese HIV-infected patients.

Microleakage of endodontic temporary restorative materials.

This study compared the sealing of Caviton, Cavit, and IRM at two powder to liquid ratios of 6 g/ml and 2 g/ml. Standard endodontic access preparations were made in 140 noncarious, nonrestored crowns of extracted human molars. They were divided into six groups, including positive and negative controls. Microleakage assessment was evaluated by basic fuchsin dye penetration after thermal cycling (5 to 55 degrees C for 100 cycles). The results indicated that Caviton provided the best seal, followed by Cavit. Cavit demonstrated better sealing than IRM at the powder to liquid ratio of 6 g/ml and 2 g/ml. There was a statistically significant difference in leakage between the Cavit group and IRM (powder to liquid = 6 g/ml), between the Cavit group and IRM (powder to liquid = 2 g/ml) group (p < 0.05). However, no statistically significant difference between the two different powder to liquid ratio groups of IRM was disclosed.