ABSTRACT
Aim: The purpose of this investigation was to evaluate the association of physicochemical properties and antimicrobial peptide levels of saliva with caries activity in children. Materials and Methods: The required volume of unstimulated saliva was collected from 41 children aged 3–12 years with no systemic diseases. Caries activity was calculated using DMFS and dmfs records for each participating child. Collected saliva samples were then examined for their flow rate, pH, and buffering capacity. The concentration of three peptides was assessed including LL-37, human neutrophil peptide (HNP) 1–3, and human beta-defensin (HBD)-3 through an enzyme-linked immunosorbent assay. The correlation between caries activity score (CAS) and salivary variables was looked using the linear regression and Spearman's correlation method. The comparison of CAS means between high- and low-value groups of salivary items was performed using independent sample t-test while the association of CAS and salivary parameters in categorical scale was tested by Chi-square test. Results: No statistically significant differences were found between the CAS means at low and high categories of each salivary physicochemical parameter and those of antimicrobial peptides. There was a negative correlation between HNP1–3 and CAS and also between HBD-3 and CAS, but these results were not statistically meaningful. High HNP1–3 concentration was noted in 67% of the low caries rate group and 29% of the high caries rate group, with a statistically significant difference between the low and high caries rate groups (P = 0.019). Conclusion: Salivary inherent factors are not dominant determinants in caries activity. The current results may suggest that ?-defensins (HNP1–3) have a protective role against dental caries.
ABSTRACT
Aim: This study was aimed to evaluate the effect of steam sterilization on the accuracy (within 10%) of friction‑style mechanical torque limiting devices (F‑S MTLDs) to achieve their target torque values. Materials and Methods: Fifteen new F‑S MTLDs were selected from Astra Tech (25 Ncm, Hader SA, La Chaux‑de‑Fonds, Switzerland), BioHorizons (30 Ncm, Dynatorq ITL, Irvine, California, USA), Dr. Idhe (15‑60 Ncm, Dr. Idhe Dental, Eching/Munich, Germany). Every peak torque measurement was tested ten times before steam sterilization using Tohnichi torque gauge (6Tohnichi‑BTG (‑S), Japan). Steam sterilization was performed using a 100 cycle autoclave. Preparation steps were carried out for the devices before each autoclave sterilization cycle. Peak torque measurements were repeated after every sterilization cycle. Mean difference between the measured and the targeted torque values were evaluated before and after aging. Repeated‑measures of ANOVA were used to compare the differences of accuracy between subjects. Bonferroni post‑hoc test was used for pairwise comparison. Results: Autoclaving resulted in an increase in the error values (the difference between peak torque and target torque values) in all the three groups studied (P < 0.05), with only Astra Tech devices showing >10% (maximum 12%) difference from their torque values in 5% of the measurements. Conclusion: Steam sterilization effect differs between target torque and measured peak values with an increase trend. The peak torque values showed a significant decrease for BioHorizons, while a significant increase was noted for Astra Tech and no significant change in Dr. Idhe group after sterilization. Clinical Implication: Within the limitation of this study the torque output of each individual device deviated in varying degrees from target torque values. However, the majority of the new frictional‑style devices tested in this study, delivered fairly consistent torque output within 10% of their preset target values after sterilization. Astra Tech devices were the only one showing more than 10% difference from their torque values in 5% of the measurements. Combined effects of sterilization and aging still needs to be determined.