Current situation and strategy on perforation repair / 华西口腔医学杂志

Perforations are common complications of root canal therapy. In clinic, perforations that were improperly and untimely repaired can seriously affect the prognosis of teeth after root canal treatment. At present, the status of perforation repair in our country is worrisome. This paper focused on the progress of perforation repair in the country by discussing the current situation of repair methods and materials. This review aims to improve knowledge and aid clinical doctors in the sophistication of perforation repair in order to improve the retention rate of root-canal-treated teeth.

Morphology and microleakage study of repairing subpulpal wall perforation with resinous inlay / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study is to study the sealing ability and the furcal appearance of repairing subpulpal wall perforation with resinous inlay.</p><p><b>METHODS</b>Fifty newly extracted human molars were randomly divided into three experiment groups (group A, group B, group C, 15 teeth each) and one control group (5 teeth). In experiment groups, perforations were made perpendicularly to the center of the pulp chamber floor. Perforations of group A and B were repaired with resinous inlay and sealed by AH Plus sealer and luting glass-ionomer, respectively. Perforations of group C were directly repaired using light-cure composite resin. Perforations were not made in five teeth of control group. The furcal appearances were evaluated under stereomicroscope after repairing. Microleakage was measured by glucose oxidase detection.</p><p><b>RESULTS</b>The fineness rate of furcal appearances with resinous inlay repairing were 83.3%, while the fineness rate of furcal appearances with light-cure composite resin directly repairing were 46.7%. There were statistics difference between resinous inlay repairing and light-cure composite resin directly repairing (P<0.05). There were statistics difference among the daily microleakage of three experiment groups, group A<group B<group C (P<0.05).</p><p><b>CONCLUSION</b>Using resinous inlay to repair the subpulpal wall perforation can improve the sealing effect and avoid material overextension. AH Plus can be used as perforation sealant because of its better sealing ability.</p>

Cytotoxicity evaluation of three kinds of perforation repair materials on human periodontal ligament fibroblasts in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To select three kinds of perforation repair materials, mineral trioxide aggregate (MTA), Z350, amalgam. And to evaluate the cytotoxicity of three kinds of perforation repair materials on human periodontal ligament fibroblasts (HPDLF) in vitro.</p><p><b>METHODS</b>The proliferation of HPDLF to three perforation repair materials were examined by methyl thiazolyl tetrazolium (MTT) assay at 1, 3 and 5 days. The mRNA expression levels of bone-associated alkaline phosphatase (ALP) and osteocalcin (OC) were determined using a real-time quantitative polymerase chain reaction (PCR).</p><p><b>RESULTS</b>MTA shew almost no inhibition to HPDLF, the expression of ALP mRNA and OC mRNA in the HPDLF cultured on MTA were higher. Z350 induced a slight inhibition to HPDLF, and the expression of ALP mRNA but there was no difference in the expression of OC mRNA. Cell proliferation was significantly impaired by amalgam with grade 3, and the expression of ALP mRNA and OC mRNA were significantly reduced.</p><p><b>CONCLUSION</b>MTA have minimum cytotoxicity on HPDLF and can promote cell differentiation and regenerate of periodontal tissue. Z350 have lower cytotoxicity on HPDLF. Amalgam show highest cytotoxicity on HPDLF in the three materials and inhibit cells differentiation.</p>

Use of calcium sulfate as internal matrix to repair furcal perforations / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of internal matrix on sealing ability and furcal appearance of perforations repair with amalgam and resin.</p><p><b>METHODS</b>Perforations created in the pulpal floor of human extracted molars were repaired as follows: Amalgam, amalgam plus calcium sulfate, light-cured resin, and resin plus calcium sulfate (15 teeth/group). The furcal appearance of samples was evaluated under an operating microscope after repair. With the leakage test device, coronal 1 mol/L glucose solution was forced toward the pulpal floor. Leakage was measured by the concentration of leaked glucose in bottom reservoir at 1, 2, 4, 7, 10, 15 and 20 days with enzymatic glucose oxidase method.</p><p><b>RESULTS</b>No significant difference was found between group 1 and group 2 (P > 0.05). Leakage in group 4 was obviously lower than group 3 (P < 0.05) after the 7th day.</p><p><b>CONCLUSION</b>Calcium sulfate significantly improved the sealing effect of resin and provided successful barriers against its overextension.</p>

Clinical analysis of 1 423 cases of root canal therapy / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical quality of root canal therapy (RCT) in West China Dental Hospital of Sichuan University.</p><p><b>METHODS</b>1 423 RCT teeth were finished from Mar. 2001 to Feb. 2002 in West China Dental Hospital. Root canal filling quality and treatment period of these teeth were evaluated. 695 teeth of the total were revisited 2 years later and 2-year success rate were evaluated.</p><p><b>RESULTS</b>The ratios of adequate filling, underfilling, and overfilling were 79.97%, 14.62% and 5.41%, receptively. Full canal RCT ratio of molar was 89.44%. Average RCT treatment period was 2.8 weeks. 2-year success rate of RCT was 94.39%.</p><p><b>CONCLUSION</b>Clinical RCT level of West China Dental Hospital was satisfactory from 2001 to 2002.</p>

A study of the related factors and prophylactic measures of endodontic interappointment emergencies / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To estimate the related factors and prophylactic measures of endodontic interappointment emergencies (EIE).</p><p><b>METHODS</b>The clinical cases were divided into three groups. Cases in the routine group were treated according to the routine procedures of root canal therapy. Cases in the medicament group took dexamethasone tablets after the instrumentation. Root canals in the drainage group were prepared at the first visit and had been left open for two or three days. The related factors were recorded. The incidences and flare-up index (FUI) value of EIE were statistically analyzed.</p><p><b>RESULTS</b>The EIE incidence of the routine group was 19.1%. The EIE incidence and FUI value of the overinstrumented teeth were significantly higher than those of other teeth (P < 0.05). EIE were not significantly related to the age, gender, tooth location and pathosis of the pulpal and periapical tissue (P > 0.05). The FUI value of the medicament group was significantly lower than that of the routine group (P < 0.05). Less severe EIE occurred in the cases of the drainage group than those of the control group (P > 0.05).</p><p><b>CONCLUSION</b>The occurrence of EIE was significantly related to overinstrumentation. Taking dexamethasone may relieve EIE.</p>