Is Periodontitis a Risk Factor for Lung Cancer? A Meta-Analysis and Detailed Review of Mechanisms of Association.

Background: Numerous studies have explored the correlation of periodontal disease (PD) with the risk of lung cancers, but the findings were inconsistent. Therefore, we did a meta-analysis to ascertain the correlation of PD with the risk of incident lung cancer. Methods: The authors searched relevant studies in databases (PubMed, Web of Science, Scopus, Embase, and MEDLINE) till November 2020. We registered the study at the International database of Prospectively Registered Systemic Reviews under the CRD42020198119. The summary relative risk (RR) along with a 95% confidence interval (CI) was calculated using fixed-effects models. Results: Twelve studies were included in the qualitative synthesis. The pooled analysis revealed that PD was significantly associated with an increased risk of lung cancer (RR 1.71; 95%CI 1.61-1.81; P < 0.01). Subgroup analysis was performed based on gender distribution, geographic location, and type of studies. Conclusion: From this current evidence, PD is a potential risk factor for the development of lung cancer. The risk for incidence of lung cancer is surged twice in the patients with PD, even though age and smoking are controlled in the studies.

Cyclic Fatigue Resistance and Surface Roughness of Rotary NiTi Instruments after Simulated Clinical Use in Curved Root Canals - An Atomic Force Microscopy Study

Abstract Objective: To examine the cyclic fatigue resistance and surface topography of TruNatomy and ProTaper Gold nickel-titanium rotary files and evaluate the presence of alterations to surface topography following instrumentation in simulated curved canals. Material and Methods: Twenty-four nickel-titanium instruments, twelve each of TN and PTG file systems, were evaluated for cyclic fatigue resistance. The rotary files were rotated in a simulated root canal with standardized diameter, angle of curvature, and radius of curvature in a custom-made cyclic fatigue testing device until the instrument fracture occurred. The time to fracture for each instrument was recorded with a stopwatch; in seconds in each group. Fractured instruments were subjected to atomic force microscopy analysis measuring the average roughness and the root mean square values to investigate surface features of endodontic files. Mean values and standard deviation were calculated. Data were analyzed using the Mann-Whitney U test. Results: Time to fracture was marginally higher in PTG instruments than in the TN file systems. PTG files exhibited higher surface roughness when compared with TN files (p<0.05). Conclusion: TN file system had a higher cyclic fatigue resistance than PTG. Cyclic fatigue causing file breakage did affect the surface topography of the files. PTG files showed a higher surface porosity value than the TN files (AU).

A pilot study of dentists' assessment of caries detection and staging systems applied to early caries: PEARL Network findings.

The International Caries Detection and Assessment System (ICDAS II) and the Caries Classification System (CCS) are caries stage description systems proposed for adoption into clinical practice. This pilot study investigated clinicians' training in and use of these systems for detection of early caries and recommendations for individual tooth treatment. Patient participants (N = 8) with a range of noncavitated lesions (CCS ranks 2 and 4 and ICDAS II ranks 2-4) identified by a team of calibrated examiners were recruited from the New York University College of Dentistry clinic. Eighteen dentists-8 from the Practitioners Engaged in Applied Research and Learning (PEARL) Network and 10 recruited from the Academy of General Dentistry-were randomly assigned to 1 of 3 groups: 5 dentists used only visual-tactile (VT) examination, 7 were trained in the ICDAS II, and 6 were trained in the CCS. Lesion stage for each tooth was determined by the ICDAS II and CCS groups, and recommended treatment was decided by all groups. Teeth were assessed both with and without radiographs. Caries was detected in 92.7% (95% CI, 88%-96%) of the teeth by dentists with CCS training, 88.8% (95% CI, 84%-92%) of the teeth by those with ICDAS II training, and 62.3% (95% CI, 55%-69%) of teeth by the VT group. Web-based training was acceptable to all dentists in the CCS group (6 of 6) but fewer of the dentists in the ICDAS II group (5 of 7). The modified CCS translated clinically to more accurate caries detection, particularly compared to detection by untrained dentists (VT group). Moreover, the CCS was more accepted than was the ICDAS II, but dentists in both groups were open to the application of these systems. Agreement on caries staging requires additional training prior to a larger validation study.