The effect of an intraorifice barrier and base under coronal restorations on the healing of apical periodontitis: a randomized controlled trial.

AIM: To evaluate the effect of intraorifice barriers and bases on the healing of apical periodontitis following root canal treatment in mandibular molars. METHODOLOGY: A total of 120 permanent mandibular molars with necrotic pulps and periapical radiolucencies (PAI score ≥ 3) were recruited. Root canal treatment was performed in all teeth using a standard protocol, following which they were randomly allocated to one of the three treatment groups: intraorifice barrier group: coronal 3-mm gutta-percha was removed and replaced with glass-ionomer cement (GIC) barrier. The floor of the pulp chamber was then sealed with 2-mm-thick GIC base followed by final composite resin restoration; base group: received 2-mm-thick GIC base before placement of composite resin restoration; and control group: had pulp chamber entirely filled with composite resin only. Follow-up was done at 3, 6, 9 and 12 months. Combination of clinical and radiographic parameters were used to assess treatment outcome. The data were analysed using Kruskal-Wallis, chi-square and Wilcoxon signed-rank tests and logistic regression analysis. RESULTS: At the end of 12 months, the base group had the most favourable healing (97.1%), whilst the control group had the least favourable healing (83.8%). The intraorifice barrier group had healing of 92.1%. However, there was no significant difference in healing between groups at the end of the follow-up period (P > 0.05). Additional subgroup analysis revealed a nonsignificant effect of periodontal status and root filling level on periapical healing. CONCLUSION: The use of an additional barrier under permanent restorations did not significantly improve the outcome of primary root canal treatment in posterior teeth after 12 months. However, its influence in the long term requires further evaluation.

2D and 3D radiographic outcome assessment of the effect of guided tissue regeneration using resorbable collagen membrane in the healing of through-and-through periapical lesions - a randomized controlled trial.

AIM: To evaluate the effect of collagen membrane on the healing of through-and-through periapical lesions using 2-dimensional (2D) and 3-dimensional (3D) imaging techniques. METHODOLOGY: Thirty-two patients with periapical radiolucencies measuring at least 10 mm and with confirmed loss of buccal and lingual cortical plates were randomly divided into GTR and control groups. Periapical surgery was performed in both groups, using a resorbable collagen membrane in the GTR group only. 2D healing was evaluated according to Molven's criteria, while 3D healing was assessed using modified PENN 3D criteria, RAC indices and the B index, 12 months after surgery. Data were analysed using Chi-square, Mann-Whitney and Wilcoxon signed rank tests. RESULTS: Thirty patients were analysed at the 12 months follow-up. Both groups had a significant reduction in the size of lesions [92 ± 12% (control) and 86 ± 14% (GTR) in 2D and 85 ± 19% (Control) and 82 ± 13% (GTR) in 3D], with no significant difference between the groups (P > 0.05). A total of 29(14 control, 15 GTR) teeth and 26(13 control, 13 GTR) teeth were classified as success according to Molven's (2D) and modified PENN 3D criteria, respectively, with no significant difference in success between 2D and 3D assessments. RAC indices of 3D images revealed the greatest percentage of complete healing in R scores (55% for Control, 41% for GTR), whereas cortical plate had the lowest percentage of healing (30% for Control, 27% for GTR) (P > 0.05). Only 2 (13%) patients in each group had complete healing using the B index. CONCLUSION: Periapical surgery with or without GTR was a predictable and viable solution for through-and-through lesions. There was no benefit in using a collagen membrane with regard to the outcome of periapical surgery in through-and-through lesions. Both cone beam computed tomography (CBCT) and periapical radiographs (PA) allowed similar assessment of healing after periapical surgery.

Effect of continuous ultrasonic irrigation on postoperative pain in mandibular molars with nonvital pulps: a randomized clinical trial.

AIM: To evaluate via a randomized clinical trial the effect of continuous ultrasonic irrigation (CUI) on postoperative pain in mandibular molars with nonvital pulps. METHODOLOGY: Seventy mandibular molars with nonvital pulps and apical periodontitis were treated endodontically using two different irrigation techniques. The patients were randomly allocated to one of two groups, CUI (n = 35) and syringe irrigation (SI) (n = 35). The CUI group received irrigant activation using a Proultra Piezoflow ultrasonic needle as the final irrigation protocol, whilst in the SI group, the final irrigation was performed using 27-gauge needle. All the patients were prescribed ibuprofen 400 mg to be taken every 8 h, if required. Postoperative pain using a visual analog scale and analgesic intake were recorded everyday for 7 days. Data were analysed using chi-Square, Mann-Whitney and multiple linear regression tests. RESULTS: Mean postoperative pain was lower in the CUI as compared to SI group, but the difference was significant on the first day only (P = 0.032). The overall 24-h pain prevalence was 41.4%. CUI had a lower incidence of pain (31.4%) as compared to the SI group (51.4%), but the difference was not significant (P > 0.05). No significant difference was observed in analgesic consumption between the groups (P > 0.05). Regression analysis revealed a significant association of mean postoperative pain at 24 h with the irrigant protocol (P = 0.017) and preoperative pain (P = 0.000). CONCLUSION: A significant difference was observed between CUI and syringe irrigation on the first postoperative day following chemo-mechanical preparation. However, the benefit observed was not clinically relevant.

Effect of maintaining apical patency on endodontic pain in posterior teeth with pulp necrosis and apical periodontitis: a randomized controlled trial.

AIM: To evaluate the association between apical patency and post-operative pain in posterior teeth with pulp necrosis and apical periodontitis. METHODOLOGY: Sixty-eight patients requiring primary root canal treatment in mandibular first molars with necrotic pulps and apical periodontitis were included. The patients were randomly allocated to one of two groups: patency (n = 34) and nonpatency (n = 34). After administering local anaesthesia, root canal preparation was completed using ProTaper rotary instruments. A size 10 K-file was used as a patency file and carried 1 mm beyond the working length (WL) between each instrument change in the patency group, while it was carried up to WL in the nonpatency group. Patients were asked to record their pain experience on a pain chart daily for 7 days. Three patients (two in the patency group, one in the nonpatency group) did not return with completed pain charts on the subsequent visit, resulting in a total of 65 patients for the final analysis (patency, n = 32; nonpatency, n = 33). Data was analysed using Chi Square test, t-test, Mann-Whitney test and Wilcoxon Signed Ranks test. RESULTS: Overall, 43% of the patients experienced post-operative pain. The patency group had less incidence of pain (34%) as compared to the nonpatency group (52%), but the difference was not significant (P = 0.163). CONCLUSION: Maintenance of apical patency during chemomechanical preparation had no significant influence on post-operative pain in posterior teeth with necrotic pulps and apical periodontitis.

Cultured buffalo umbilical cord matrix cells exhibit characteristics of multipotent mesenchymal stem cells.

Recent findings have demonstrated umbilical cord, previously considered as a biomedical waste, as a source of stem cells with promising therapeutic applications in human as well as livestock species. The present study was carried out to isolate the umbilical cord matrix cells and culture for a prolonged period, cryopreserve these cells and test their post-thaw viability, characterize these cells for expression of stem cell markers and differentiation potential in vitro. The intact umbilical cord was taken out of the amniotic sac of a fetus and then incised longitudinally to remove umbilical vessels. Wharton's jelly containing tissue was diced into small pieces and placed in tiny drops of re-calcified buffalo plasma for establishing their primary culture. Confluent primary culture was trypsinized and passaged with a split ratio of 1:2 for multiplication of cells. Cryopreservation of cells was performed at three different passages in cryopreservation medium containing 15%, 20% and 25% fetal bovine serum (FBS). A significant increase in post-thaw viability was observed in cells cryopreserved in freezing medium with higher concentration of FBS. After re-culturing, frozen-thawed cells started adhering, and spike formation occurred within 4-6 h with similar morphology to their parent representative cultures. The normal karyotype and positive expression of alkaline phosphatase and pluripotency genes OCT4, NANOG and SOX2 were observed at different passages of culture. When induced, these cells differentiated into adipogenic and osteogenic cells as confirmed by oil red O and alizarin red stains, respectively. This study indicates that buffalo umbilical cord matrix cells have stemness properties with mesenchymal lineage restricted differentiation and limited proliferation potential in vitro.

Comparative evaluation of antimicrobial efficacy of Syzygium aromaticum, Ocimum sanctum and Cinnamomum zeylanicum plant extracts against Enterococcus faecalis: a preliminary study.

AIM: To evaluate the antimicrobial efficacy of Ocimum sanctum, Cinnamomum zeylanicum, Syzygium aromaticum and 3% sodium hypochlorite (NaOCl) against Enterococcus faecalis in planktonic suspension and biofilm phenotypes. METHODOLOGY: The antibacterial efficacy of different concentrations of aqueous ethanolic extracts of O. sanctum, C. zeylanicum and S. aromaticum against E. faecalis at various time intervals was assessed using the agar well diffusion test, microdilution test and biofilm susceptibility assay (BSA) on cellulose nitrate membrane as well as in a tooth model. NaOCl was used as the positive control. Distilled water was used as negative control for agar diffusion and microdilution tests and phosphate-buffered saline for the BSA. The results of the agar diffusion test were analysed statistically using anova and Tukey's tests. RESULTS: Cinnamomum zeylanicum, S. aromaticum and O. sanctum exhibited minimum bactericidal concentration at 10%, 10% and 40%, respectively. Cinnamomum zeylanicum, S. aromaticum, O. sanctum and NaOCl showed complete bacterial inhibition in planktonic form after exposure of 30, 15, 35 and 1 min, respectively. In BSA on cellulose nitrate membrane, NaOCl was associated with complete bacterial inhibition after contact of 2 min, whilst 10% C. zeylanicum, 10% S. aromaticum and 40% O. sanctum showed cessation of growth after 12, 12 and 24 h, respectively. The results of BSA on tooth model were similar except for O. sanctum, which was not included in the model. CONCLUSION: Cinnamomum zeylanicum, S. aromaticum and O. sanctum demonstrated antimicrobial activity against planktonic and biofilm forms of E. faecalis with C. zeylanicum and S. aromaticum having better antimicrobial efficacy than O. sanctum. NaOCl had superior antimicrobial efficacy amongst all the groups.

Tertiary dentinogenesis with calcium hydroxide: a review of proposed mechanisms.

Calcium hydroxide has been used extensively in dentistry for a century. Despite its widespread use as a pulp-capping agent, its mechanisms of action still remain ambiguous. Understanding its modes of action will lead to a broader understanding of the mechanisms associated with induced dentinogenesis and help in optimizing the currently available agents to target specific regenerative processes to obtain the best possible clinical outcomes. A literature search relating to mechanisms of dentinogenesis of calcium hydroxide up to December 2011 was carried out using pubmed and MEDLINE database searches as well as manual searching of cross-references from identified studies. Resulting suggestions regarding dentinogenic mechanisms of calcium hydroxide range from direct irritating action of the material to induction of release of biologically active molecules. The purpose of this article is to discuss various mechanisms through which calcium hydroxide may induce tertiary dentinogenesis in the light of observations made in included studies.

Transvenous renal biopsy in an ex vivo swine kidney model: a comparison of five devices.

PURPOSE: To compare the efficacy of end-cut and side-cut devices in transvenous renal biopsies of ex vivo swine kidneys and to examine the use of the swine kidney as an animal model in this setting. MATERIALS AND METHODS: Biopsy specimens of ex vivo swine kidneys were obtained after selective renal vein cannulation with use of five separate biopsy devices (Quick-Core 16 gauge and 18 gauge, Colapinto 16 gauge, Mansfield biopsy forceps, Flexi-Temno 16 gauge). Biopsy specimens were defined as the material obtained from three separate passes at a given site, with 30 biopsy specimens obtained per device. Capsular perforation was examined for each pass. A blinded pathologist recorded the presence of tissue and the number of glomeruli present for each pass. A diagnostic biopsy was defined as six or more glomeruli obtained. RESULTS: The median number of glomeruli obtained for each device per biopsy was Colapinto 0.0 (range, 0-13), Mansfield 0.0 (range, 0-19), Flexi-Temno 2.0 (range, 0-13), 18-gauge Quick-Core 8.5 (range, 0-30), and 16-gauge Quick-Core 16.0 (range, 0-52). The Quick-Core 16-gauge and 18-gauge devices obtained diagnostically adequate biopsy specimens 83% and 77% of the time, respectively, compared to 20% or less for the other devices. CONCLUSION: The Quick-Core 16-gauge and 18-gauge side-cut biopsy devices are the most efficacious for obtaining diagnostic quality biopsy specimens in the ex vivo swine kidney model.