Periodontal grading-estimation of responsiveness to therapy and progression of disease.

OBJECTIVE: To investigate the capability of periodontal grading to estimate the progression of periodontal disease and the responsiveness to therapy. MATERIALS AND METHODS: Eighty-four patients who underwent non-surgical therapy (NST) were included. Direct and indirect evidence of progression were determined according to the current classification. Responsiveness to therapy was examined using mean pocket probing depths reduction (PPDRed), reduction of bleeding on probing (BOPRed), and the rate of pocket closure (%PC) after six months. RESULTS: Statistical analysis revealed no agreement between direct and indirect evidence in grading periodontitis (κ = 0.070). The actual rate of progression as determined by longitudinal data was underestimated in 13% (n = 11), overestimated in 51% (n = 43) and correctly estimated in 30% (n = 36) by indirect evidence. No significant differences in responsiveness to therapy were observed in patients graded according to direct evidence. Using indirect evidence, patients assigned grade C showed more PPDRed but less BOPRed and lower %PC compared to grade B. CONCLUSION: The present data indicate that indirect evidence may lead to inaccuracies compared to direct evidence regarding the estimation of periodontal progression. However, indirect evidence seems to be more suitable in the estimation of responsiveness to therapy than direct evidence, helping to identify cases that are more likely to require additional therapies such as re-instrumentation or periodontal surgery. CLINICAL RELEVANCE: Regarding the estimation of disease progression and responsiveness to periodontal therapy, accuracy and reliability of both direct and indirect evidence are limited when grading periodontitis.

Probing pocket depth reduction after non-surgical periodontal therapy: Tooth-related factors.

BACKGROUND: To investigate tooth-related factors that influence the reduction of probing pocket depths (PPD) after non-surgical periodontal therapy (NST). METHODS: Seven hundred forty-six patients with a total of 16,825 teeth were included and retrospectively analyzed. PPD reduction after NST was correlated with the tooth-related factors; tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration; using logistic multilevel regression for statistical analysis. RESULTS: NST was able to reduce probing depth overall stratified probing depths (1.20 ± 1.51 mm, p ≤ 0.001). The reduction was significantly higher at teeth with higher probing depths at baseline. At pockets with PPD ≥ 6 mm, PPD remains high after NST. Tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration are significantly and independently associated with the rate of pocket closure. CONCLUSIONS: The tooth-related factors: tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration had a significant and clinically relevant influence on phase I and II therapy. Considering these factors in advance may enhance the prediction of sites not responding adequately and the potential need for additional treatment, such as re-instrumentation or periodontal surgery, to ultimately achieve the therapy end points.

Influence of decision-making algorithms on the diagnostic accuracy using the current classification of periodontal diseases-a randomized controlled trial.

OBJECTIVES: To examine the influence of the decision-making algorithms published by Tonetti and Sanz in 2019 on the diagnostic accuracy in two differently experienced groups of dental students using the current classification of periodontal diseases. MATERIALS AND METHODS: Eighty-three students of two different clinical experience levels were randomly allocated to control and study group, receiving the staging and grading matrix, resulting in four subgroups. All diagnosed two patient cases with corresponding periodontal charts, panoramic radiographs, and intraoral photographs. Both presented severe periodontal disease (stage III, grade C) but considerably differed in complexity and phenotype according to the current classification of periodontal diseases. Controls received the staging and grading matrix published within the classification, while study groups were additionally provided with decision-trees published by Tonetti and Sanz. Obtained data was analyzed using chi-square test, Spearman's rank correlation, and logistic regression. RESULTS: Using the algorithms significantly enhanced the diagnostic accuracy in staging (p = 0.001*, OR = 4.425) and grading (p < 0.001**, OR = 30.303) regardless of the clinical experience. In addition, even compared to the more experienced control, less experienced students using algorithms showed significantly higher accuracy in grading (p = 0.020*). No influence on the criteria extent could be observed comparing study groups to controls. CONCLUSION: The decision-making algorithms may enhance diagnostic accuracy in dental students using the current classification of periodontal diseases. CLINICAL RELEVANCE: The investigated decision-making algorithms significantly increased the diagnostic accuracy of differently experienced under graduated dental students and might be beneficial in periodontal education.

UV generation via periodically poled MgO:LiTaO3 circular waveguide crystal and diode-based master oscillator power amplifier.

Lasers with emission wavelengths in the near-ultraviolet (UV) spectral range have been used in many applications across various fields, and the demand for these lasers has been on the rise. For example, in medicine, near-UV light has been used for fluorophore excitation. Although laser diodes emitting in this region exist, single longitudinal mode lasers emitting at 380 nm with high optical power are limited. One of the solutions to this problem is the use of second harmonic generation by a non-linear crystal. In this work, single-longitudinal-mode laser emission at 380.5 nm with an optical power of up to 13 mW has been achieved. The emission was realized by frequency doubling using a periodically poled circular waveguide crystal of stoichiometric L i T a O 3 doped with MgO (PPMgSLT) pumped by a master oscillator power amplifier with optical power up to 5 W. A distributed Bragg reflector ridge waveguide laser diode at 761 nm was used as the master oscillator and a tapered amplifier as the power amplifier.

Nocturnal hypoxemic burden during positive airway pressure treatment across different central sleep apnea etiologies.

INTRODUCTION: Nocturnal hypoxemia is associated with increased cardiovascular mortality. Here, we assess whether positive airway pressure by adaptive servo-ventilation (ASV) reduces nocturnal hypoxemic burden in patients with primary central sleep apnea (primary CSA), or heart failure related central sleep apnea (CSA-HF) and treatment emergent central sleep apnea (TECSA). METHODS: Overnight oximetry data from 328 consecutive patients who underwent ASV initiation between March 2010 and May 2018 were retrospectively analyzed. Patients were stratified into three groups: primary CSA (n = 14), CSA-HF (n = 31), TECSA (n = 129). Apnea hypopnea index (AHI) and time spent below 90% SpO2 (T90) was measured. Additionally, T90 due to acute episodic desaturations (T90Desaturation) and due to non-specific and non-cyclic drifts of SpO2 (T90Non-specific) were assessed. RESULTS: ASV reduced the AHI below 15/h in all groups. ASV treatment significantly shortened T90 in all three etiologies to a similar extent. T90Desaturation, but not T90Non-specific, was reduced by ASV across all three patient groups. AHI was identified as an independent modulator for ΔT90Desaturation upon ASV treatment (B (95% CI: -1.32 (-1.73; -0.91), p < 0.001), but not for ΔT90 or ΔT90Non-specific. Body mass index was one independent predictor of T90. CONCLUSIONS: Across different central sleep apnea etiologies, ASV reduced AHI, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Whether adjunct risk factor management such as weight-loss can further reduce T90 warrants further study.

Emission behavior of distributed Bragg-reflector ridge waveguide lasers exposed to strong optical feedback.

In this work, the influence of strong optical feedback on the emission behavior of distributed Bragg-reflector ridge waveguide diode lasers emitting at 1120 nm with different cavity lengths and facet reflectivities is investigated. Based on measurements of the optical output power, central emission wavelength, and spectral emission width, the different diode laser types are compared while optical feedback up to -8dB is applied. The observed changes of the optical output power and emission wavelength as well as the occurrence of coherence collapse states give insight into the resistance against feedback of the different diode laser types.