Questionable accuracy of CBCT in determining bone density: A comparative CBCT-CT in vitro study.

BACKGROUND: The accuracy of the estimation of radiological bone density with the use of the cone-beam computed tomography (CBCT) grayscale is still questionable. Standardization and correlation with the gold standard computed tomography (CT) Hounsfield units (HU) is required prior to clinical application. OBJECTIVES: The objective of the present study was to evaluate the reliability of the grayscale for the estimation of bone density, using samples with intact soft tissue in order to substantiate the clinical use of the scale. MATERIAL AND METHODS: A total of 240 sites in 20 goat heads were scanned to obtain radiological bone mineral density via Hounsfield units in CT and the grayscale in CBCT. The anatomical architecture of soft tissues was preserved for all samples. Two observers obtained the data, which consisted of 3 variables (mean, minimum and maximum) for both scales. The statistical analysis of the data was conducted using Cronbach's alpha, Pearson's correlation coefficients, the independent samples t tests, and regression analysis. RESULTS: Differences in the means of the mean, minimum and maximum values between the 2 scales were statistically highly significant (p = 0.000). The correlation coefficients for the mean, minimum and maximum values of the 2 scales were 0.496, 0.037 and 0.396, respectively. Regression analysis revealed that the R2 values for the mean, minimum and maximum values were 29.79%, 21.05% and 19.45%, respectively. CONCLUSIONS: The positive but weak correlation between the 2 scales and the low predictive reliability of the grayscale reveals its questionable applicability for the estimation of density in comparison with the standard HU.

Efficacy of Diode Laser Ablation and Low Level Laser Therapy on Healing and Bacterial Load Reduction at Intraoral Biopsy Site.

Statement of the Problem: Healing complications after the conventional surgical biopsy procedure along with bacterial colonization indicates scope for sophisticated techniques. Amalgamation of photo-disinfection along with healing properties of diode laser with practiced biopsy technique can help in dealing with post biopsy complications. Purpose: The present study will analyze the possibility of conjugation of conventional surgical biopsy technique with diode laser regarding its superior properties for achieving better healing and analgesia along with sterilization of the biopsy site. Materials and Method: A randomized control trial was done where punch biopsy procedure was performed for homogenous leukoplakia. Patients were randomly divided into laser group (Test group) and control group. Test group received laser ablation and low level laser therapy (LLLT) on surgical site along with warm saline rinses whereas control group was prescribed with systemic analgesic and antibiotics. Pain on visual analogue scale (VAS), erythema along with the size of defect was evaluated on day 0, 2 and 4. Swabs were collected from the biopsy site and culture was done for evaluation of bacterial load. Results: Highly statistical significant values indicating laser induced analgesia were obtained after analysis for 2nd and 4th day (p= 0.00). Erythema and biopsy defect size evaluation showed significant results for 2nd day (p value 0.023 and 0.004 respectively), which showed absence of erythema and enhancement of healing in test group compared to controls. Statistical significant results were obtained for estimation of bacterial colonization with p value as 0.00, 0.00 for 2nd and 4th day claiming laser supported bacterial disinfection. There was a significant percentage increase on 2nd (p= 0.013) and decrease on 4th post-operative day (p= 0.022). Conclusion: The results encourage the conjugation of conventional incisional punch biopsy with low level lasers to avoid systemic intervention for post biopsy complications.