Precision and trueness of implant placement with and without static surgical guides: An in vitro study.

STATEMENT OF PROBLEM: Malpositioning of implants is one of the main factors leading to hard- and soft-tissue deficiencies. Whether static computer-guided implant placement increases accuracy and prevents malpositioning is unclear. PURPOSE: The purpose of this in vitro study was to determine accuracy defined by trueness and precision (according to International Organization for Standardization 5725) of computer-assisted implant surgery (fully guided and partially guided) in comparison with freehand single implant placement. MATERIAL AND METHODS: Implants (n=20) were placed fully guided (sleeve-bone distance of 2, 4, or 6 mm), partially guided (guide used for pilot drill), or free hand in identical replicas produced from a cone beam computed tomography (CBCT) scan of a partially edentulous patient. The achieved implant position was digitized by using a laboratory scanner and compared with the planned position. Trueness (planned versus actual position) and precision (difference among implants) were determined. The 3D-offset at the crest of the implant (root mean square between virtual preoperative planning and postoperative standard tessellation language file) was defined as the primary outcome parameter. The means, standard deviation, and 95% confidence intervals were analyzed statistically with 1-way ANOVA and the Scheffé procedure. RESULTS: Fully guided implant surgery achieved significantly lower 3D deviations between the planned and actual implant position with 0.22 ±0.07 mm (2-mm sleeve-bone distance) than partially guided 0.69 ±0.15 mm and freehand placement 0.80 ±0.35 mm at the crest (P<.001). The distance among the implants in each group was again lowest in the fully guided group and highest in the freehand group. CONCLUSIONS: The static computer-assisted implant surgery showed high trueness and precision. The closer the sleeve to the bone, the more accurate and precise the method. Freehand implant placement was less accurate and precise than computer-assisted implant surgery (partially or fully).

Comparison of Sealing Ability of Bioceramic Sealer, AH Plus, and GuttaFlow in Conservatively Prepared Curved Root Canals Obturated with Single-Cone Technique: An In vitro Study.

BACKGROUND: Inadequate obturation techniques of the root canal system have been found to be the most frequent reason of failure post root canal treatment. An ideal endodontic sealer should fulfill all ideal requisites. The present study aimed to compare apical sealing ability between bioceramic (BC) sealer, GuttaFlow, and AH Plus. METHODOLOGY: One hundred and twenty-five curved roots of maxillary and mandibular third molar teeth with fully formed apex were collected for this study. The root canals were cleaned and shaped using a standard single-cone preparation to file at the established working length and divided into five groups of 25 each. Dye leakage was carried out. Group A: with GP, using EndoSequence BC sealer with conventional with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group B: with ceramic coated with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group C: with GP, using AH Plus sealer (Dentsply, De-Trey Konstanz, Germany) with 4% gutta-percha; Group D: with GuttaFlow bioseal (Roeko-Coltène/Whaledent, Langenau, Germany) with 4% Gutta-percha; and Group E is a negative control group. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test. RESULTS: The group AH Plus showed more leakage values than the GuttaFlow group and of two groups of BC sealer and negative control. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups. CONCLUSION: None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal.

Prevalence and Risk Factors for Oral Potentially Malignant Disorders in Indian Population.

Objective. To assess the prevalence of oral potentially malignant disorders and to determine the potential risk factors for its development in Indian population. Materials and Methods. This cross-sectional study was carried out on 1241 individuals in Indore, Madhya Pradesh. A questionnaire was designed to record information about sociodemographic characteristics, oral hygiene practices, dietary habits, and risk factors for oral potentially malignant disorders. Oral mucosal lesions were examined by a skilled person. Results. The overall prevalence of oral potentially malignant disorders was found to be 13.7% with oral submucous fibrosis (8.06%) found to be more common and erythroplakia (0.24%) found to be least prevalent. Results of Logistic Regression analysis showed that males (OR = 2.09, P value < 0.0001) who were ever consumers of tobacco (OR = 2.06, P value = 0.030) and areca nut chewing (OR = 2.64, P value = 0.004) were more likely to develop oral potentially malignant disorders compared to never consumers. Diabetic (OR = 2.21, P value = 0.014) and underweight individuals (OR = 2.23, P value = 0.007) were more likely to suffer from oral potentially malignant disorders. Conclusion. The study reinforces the association of tobacco and areca nut consumption with oral potentially malignant disorders. An association of oral potentially malignant disorders with diabetes and BMI was confirmed by this study.

Effect of non-surgical periodontal therapy on superoxide dismutase levels in gingival tissues of chronic periodontitis patients: a clinical and spectophotometric analysis.

BACKGROUND: Superoxide dismutase (SOD), an antioxidant acting against superoxide (oxygen radical, O(2)(∙-)), it is released in inflammatory pathways and causes connective tissue breakdown. Increased SOD activity in inflamed gingiva may indicate increased O(2)(∙-) radical generation by neutrophils and other inflammatory cells at the diseased site. The aim of the study was to evaluate the effects of non-surgical periodontal therapy (NSPT) on SOD levels in gingival tissues of chronic periodontitis patients. METHODS: Forty subjects: 20 periodontally healthy (Control) and 20 chronic periodontitis (Test); age range 24-55 years were recruited. Gingival tissue samples were collected by excising the inner lining of the periodontal pocket at baseline (prior to non-surgical periodontal therapy) and 2 months post therapy. In controls, tissue samples were obtained immediately after tooth extraction scheduled for orthodontic reasons. Clinical parameters included probing depth, clinical attachment level, gingival index, bleeding index, plaque index. SOD activities were assessed spectrophotometrically at baseline and 2 months post NSPT, results were analysed statistically. RESULTS: At baseline, patients with chronic periodontitis had higher mean SOD activity (2.73 ± 1.36) than the control subjects (1.12 ± 1.13) with p=0.00003 (p< 0.05). At 2 months post NSPT median SOD level (1.00) had come close to median SOD value of control group (0.85); p=0.99 (p> 0.05). The resolution of inflammation with successful NSPT resulted in decreased SOD levels as in control group. Clinical parameters in patients with chronic periodontitis showed a significant improvement 2 months post NSPT (p< 0.05). CONCLUSION: Non-surgical periodontal therapy significantly improves the clinical parameters and restores previously increased SOD levels to normal in chronic periodontitis patients.