Detection of pit and fissure sealant microleakage using quantitative light-induced fluorescence technology: an in vitro study.

This in vitro study aimed to evaluate the feasibility of quantitative light-induced fluorescence (QLF) technology for detecting the presence and severity of microleakage of pit and fissure sealants. The areas of interest (AOIs) were 160 pits and fissures of 40 extracted permanent teeth. Fluorescent images were acquired using a QLF device, and the maximum fluorescence loss ΔFmax of each AOI was analyzed. After staining and cross-sectioning of the teeth, histological dye penetration was scored on a scale of 0 to 3. The relationship between ΔFmax and microleakage depth was analyzed, and the areas under the curve (AUCs) were calculated. The │ΔFmax│ increased as microleakage depth increased. The ΔFmax values of microleakage areas showed a strong significant correlation with the histological scores of dye penetration (r = - 0.72, P = 0.001). AUC analysis showed a high diagnostic accuracy for microleakage depth (AUC = 0.83-0.91). The highest AUC of 0.91 was found when differentiating the outer half microleakage of the sealant (histological score 0 vs. 1-3). QLF technology is effective in assessing the presence and severity of microleakage, suggesting its potential for noninvasive detection and monitoring of sealant microleakage in clinical settings.

Knowledge Evaluation of Oral Diseases and Perception of Cooperation with Dental Experts for Oral Care of Nurses in Intensive Care Units in Korea: A Preliminary Study.

The aim of this study was to identify the status of education and knowledge concerning oral diseases for oral care as they relate to intensive care unit (ICU) nurses, as well as to investigate the perception of oral care education and practice, as led by dental experts. This study conducted a self-report survey consisting of 33 questions on education and knowledge about oral diseases, as well as perception of dental expert-led education and practice, targeting 240 nurses in the ICU. Finally, 227 questionnaires were analyzed, and 75.3% of the participants were staff nurses, and 41.4% were in the medical ICU. In the area of education and knowledge of major oral diseases, more than 50% of the respondents treating gingivitis, periodontitis, and dental caries did not complete dental education, and it was found that more than half of the respondents were unable to distinguish diseases of the mouth. It was recognized that more than half of nurses required dental expert-led education and practice. In this study, the education and knowledge of oral diseases of ICU nurses were found to be insufficient, and the need for the cooperation of dental experts was high. Therefore, collaboration to improve oral care practical guidelines for realistically applicable ICU patients will be needed.

The growth status of North Korean refugee adolescents in South Korea: comparison with South Korean adolescents.

AIM: To assess the growth status of North Korean refugee adolescents (NKRA) living in South Korea (SK) and compare their growth status with that of SK adolescents (SKA). SUBJECTS AND METHODS: NKRA were interviewed from 2017 to 2020, whereas the data for SKA were from the 2016 to 2018 Korea National Health and Nutrition Examination Surveys. SKA and NKRA were matched by age and gender in a 3:1 ratio and 534 SKA and 185 NKRA were enrolled. RESULTS: After adjusting for the covariates, NKRA had greater prevalences of thinness (odds ratio [OR], 11.5; 95% confidence interval [CI], 2.9-45.6) and obesity (OR, 12.0; 95% CI, 3.1-46.1) than SKA, but were not of short stature. In comparison with SKA in low-income families, NKRA had similarly greater prevalences of thinness and obesity, but not of short stature. As the length of stay of NKRA in SK increased, the prevalence of short stature and thinness did not decrease, while the prevalence of obesity increased significantly. CONCLUSION: Although they had lived in SK for several years, NKRA had greater prevalences of thinness and obesity than SKA and the prevalence of obesity increased significantly with the length of stay in SK.

Red fluorescence for assessing longitudinal tooth fractures.

BACKGROUND: This study was designed to determine whether autofluorescence emitted from longitudinal tooth fractures (LTFs) differs between fracture types, with the aim of determining which clinical factors are related to red fluorescence at the fracture line. METHODS: Thirty-three extracted teeth were classified into cracked teeth, split teeth, and root fractures using LTF types according to the American Association of Endodontists classification. The types of LTFs were identified using an operating microscope. LTF autofluorescence was captured using a fluorescence technique. Clinical examinations were performed using the preoperative factors from clinical and radiographic findings. RESULTS: Red fluorescence was identified in 82% and 83% of cracked and split teeth, respectively. None of the vertical root fractures exhibited red fluorescence (p<0.001). When red fluorescence was identified on the outer tooth surface, it penetrated into the crack line, but fluorescence that was not red at the tooth surface did not penetrate the fracture line. Among the examined preoperative clinical factors, differences between the presence and absence of red fluorescence were identified for sinus tract formation (p = 0.021), and radiographic features (p = 0.027). Regression analysis revealed a significant factor related to the red fluorescence, with sinus tract formation having a negative effect on red fluorescence (odds ratio [OR]=0.09). The presence of comprehensive periradicular lesions in radiography had a positive effect on red fluorescence (OR=5.04). CONCLUSIONS: Cracks originating from tooth crowns in certain types of LTFs were associated with red fluorescence, and cracks with red fluorescence were associated with extensive periodontal bone resorption around the teeth roots.

Efficacy of a Nickel-Titanium Ultrasonic Instrument for Biofilm Removal in a Simulated Complex Root Canal.

This study evaluated the effectiveness of NiTi ultrasonic tips for Enterococcus faecalis (E. faecalis) biofilm removal in simulated complex root canals. Sixty root canal models consisting of a 30-degree curved main canal and two lateral canals were constructed from polydimethylsiloxane and incubated with E. faecalis. Irrigants in root canals were activated using a manual syringe (SI), a stainless steel (SS) instrument, a nickel-titanium (Ni-Ti) ultrasonic instrument, or a sonic instrument (EA). Instruments of SI, SS, and NiTi-9 groups were placed 9 mm from the apex, whereas those in NiTi-2 and EA groups were placed 2 mm from the apex. The efficacy of each method was determined as the ratio of fluorescence concentration before and after activation. In the apical curved canal, the highest efficacy was found in the NiTi-2 group (99.40%), followed by SI (84.25%), EA (80.38%), SS (76.93%), and NiTi-9 (67.29%) groups. In lateral canals 1 and 2, the efficacy was the highest in the NiTi-2 group and the lowest in the SI group. The NiTi ultrasonic instrument could effectively remove biofilms in the curved canal and lateral canals. This instrument should be introduced close to the working length. An up-and-down motion of the activation instrument is recommended.

Using autofluorescence to detect bacterial contamination in root fractures.

OBJECTIVES: Conventional methods for detecting root fractures cannot assess their depth or bacterial contamination. This study was designed to measure the autofluorescence emitted from a root fracture, with the aim of determining whether this is a suitable method for quantifying the depth and bacterial invasion of a fracture. METHODS: This in vitro study investigated 33 mandibular second molars with periapical lesions that had been extracted after finding root fractures in endodontically treated teeth during intentional replantation or diagnostic surgery. The root fractures were scanned using a fluorescence technique, and the association between fluorescence parameters and fracture depth was analyzed. The significance of the association between the red fluorescence among autofluorescence parameters and bacterial contamination within the fracture was examined. RESULTS: When the depth of the root fractures was evaluated by micro computed tomography, the scattering of light in the fractures increased with depth, and there was a gradual increase in the quantitative fluorescence parameter indicating the deepest point (ΔFmax) in the fractures. In addition, we observed red fluorescence on the outer surface of deeper fractures. The tooth fractures exhibiting red fluorescence were evaluated for bacterial contamination associated with red-fluorescent porphyrin, which revealed bacterial invasion into these fractures. On the other hand, non-red-fluorescing fractures contained necrotic tissue, debris, and irritants. CONCLUSIONS: This viable fluorescent technique can potentially quantify the depth of root fractures and be used as a risk indicator for root fractures with periodontal inflammation. CLINICAL SIGNIFICANCE: The auto-fluorescence technique can be used to detect depth and bacterial contamination of root fractures. It is postulated that the auto-fluorescence can be used as a risk indicator of deep fractures and can replace conventional fracture detection methods.

Explaining the Red Fluorescence Evident on the Surface of Failed Dental Implants: Case Reports.

INTRODUCTION: It is important to identify the reasons for implant failure when planning future dental treatment. No studies have distinguished the factors that affect implant failure by evaluating the appearance of failed fixtures. PURPOSE: This study investigated these factors by evaluating the surface of implant fixtures using quantitative light-induced fluorescence-digital (QLF-D), which involves detecting the red fluorescence emitted by porphyrin metabolized by oral bacteria in a mature biofilm. MATERIALS AND METHODS: The areas of red fluorescence in QLF-D images obtained from all aspects of the fixture surface were then analyzed using quantitative analysis software. RESULTS: Red fluorescence was evident on the surface of implants that failed after at least 2 years of occlusal loading and exhibited severe bone loss. Implants with no fluorescence exhibited a clean surface in blue-light images, and the bone loss could not be observed radiographically. CONCLUSIONS: The cases presented that failed dental implant surfaces caused by periimplantitis can be detected by the red fluorescence evident as QLF-D.

Cost-effectiveness of Bedaquiline for the Treatment of Multidrug-resistant Tuberculosis in the Republic of Korea.

PURPOSE: Bedaquiline is a new drug used for the treatment of multidrug-resistant tuberculosis (MDR-TB). This study aimed to evaluate the cost-effectiveness of adding bedaquiline to a standard regimen (SR) for treating patients with MDR-TB, including extensively drug-resistant (XDR)-TB, in the Republic of Korea. METHODS: A cohort-based decision-analytic model developed in a previously published study from the United Kingdom was used, with a 20-year time horizon and a 5% discount rate for cost and effectiveness, to evaluate the incremental cost-effectiveness ratios of bedaquiline + SR and SR only. The key parameters regarding the clinical data were available via the published Phase II trial of bedaquiline. Additional parameters for recurrence, cure status, loss to follow-up, surgery, death, cost, and health utility were based on Korean data if available; otherwise the international literature data were applied. Univariate and probabilistic sensitivity analyses were conducted. FINDINGS: Based on the analysis, a patient on bedaquiline + SR would gain 1.20 quality-adjusted life-years (QALYs) at 13,961,659 Korean won (KRW) (1100 KRW = US $1) of additional cost compared with a patient administered SR only, with an incremental cost/utility ratio of 11,638,656 KRW/QALY. Bedaquiline + SR had an 80% probability of being cost-effective, at a willingness-to-pay threshold of 26 million KRW, compared with SR only. IMPLICATIONS: The results of this study suggest that, in the Republic of Korea, bedaquiline, as a part of combination therapy with SR, is a cost-effective option for the treatment of MDR-TB (including XDR-TB) compared with SR only.

Detection and Analysis of Enamel Cracks by Quantitative Light-induced Fluorescence Technology.

INTRODUCTION: The ability to accurately detect tooth cracks and quantify their depth would allow the prediction of crack progression and treatment success. The aim of this in vitro study was to determine the capabilities of quantitative light-induced fluorescence (QLF) technology in the detection of enamel cracks. METHODS: Ninety-six extracted human teeth were selected for examining naturally existing or suspected cracked teeth surfaces using a photocuring unit. QLF performed with a digital camera (QLF-D) images were used to assess the ability to detect enamel cracks based on the maximum fluorescence loss value (ΔFmax, %), which was then analyzed using the QLF-D software. A histologic evaluation was then performed in which the samples were sectioned and observed with the aid of a polarized light microscope. The relationship between ΔFmax and the histology findings was assessed based on the Spearman rank correlation. The sensitivity and specificity were calculated to evaluate the validity of using QLF-D to analyze enamel inner-half cracks and cracks extending to the dentin-enamel junction. RESULTS: There was a strong correlation between the results of histologic evaluations of enamel cracks and the ΔFmax value, with a correlation coefficient of 0.84. The diagnostic accuracy of QLF-D had a sensitivity of 0.87 and a specificity of 0.98 for enamel inner-half cracks and a sensitivity of 0.90 and a specificity of 1.0 for cracks extending to the dentin-enamel junction. CONCLUSIONS: These results indicate that QLF technology would be a useful clinical tool for diagnosing enamel cracks, especially given that this is a nondestructive method.