Reporting characteristics of nonsurgical periodontal therapy trials registered in ClinicalTrials.gov: an observational study.

Aim: To evaluate the completeness of the description of nonsurgical periodontal therapy interventions in clinical trials registered in ClinicalTrials.gov and correspondence of registered information for trial participants and outcome measures with published articles. Materials & methods: We retrieved data from ClinicalTrials.gov and corresponding publications. The completeness of intervention reporting was assessed using the Template for Intervention Description and Replication (TIDieR) checklist for oral hygiene instructions (OHI), professional mechanical plaque removal (PMPR), and subgingival instrumentation, antiseptics and antibiotics. The completeness of registration of trial protocol information was assessed according to the WHO Trial Registration DataSet for participant information (enrollment, sample size calculation, age, gender, condition) and primary/secondary outcome measures. Results: 79 included trials involved OHI (n = 38 trials, 48.1%), PMPR (n = 19, 24.1%), antiseptics (n = 11, 12.7%), or antibiotics (n = 11, 12.7%). There was a great variety in the terms used to describe these interventions. Most of the analyzed trials (93.7%) were completed and did not provide any data on study phase (74.7%). The description of intervention in the registry in ClinicalTrials.gov was inadequate for all analyzed interventions, with description inconsistencies in matching publications. There were also discrepancies in registered and published outcomes: for 39 trials with published results, 18 had different registered and reported primary outcomes, and 29 different registered and reported secondary outcomes. Conclusion: The completeness of the description of nonsurgical therapy of periodontitis in clinical trials is unsatisfactory, reducing the quality of translation of the new evidence and procedures into clinical practice. Significant discrepancy in registered and reported trial outcomes calls into question the validity of reported results and relevance for practice.

Periodontitis severity in obstructive sleep apnea patients.

OBJECTIVES: This cross-sectional study investigated the stages of periodontitis in obstructive sleep apnea (OSA) patients and risk factors associated with periodontitis severity among them. MATERIALS AND METHODS: A total of 194 patients underwent a polysomnography/polygraphy and were referred to periodontal examination. According to apnea-hypopnea index (AHI), patients were classified as mild OSA (AHI < 15) and moderate to severe OSA (AHI ≥ 15), whereas periodontitis severity was determined by the clinical attachment level (CAL) according to the recent Classification of Periodontal Diseases and Conditions. Patients were grouped into two categories: stages 1 and 2, and stages 3 and 4. RESULTS: Higher AHI values were reported in OSA patients exhibiting periodontitis stages 3 and 4 compared to OSA patients with periodontitis stages 1 and 2 (p = 0.043) and the non-periodontitis group (p = 0.044). A positive correlation was found between AHI and mean CAL (r = 0.215; p = 0.004), and between AHI and plaque scores (r = 0.292; p < 0.001). Following a multivariable regression analysis, AHI was a significant predictor of mean CAL (ß = 0.169; p = 0.031), explaining 16.4% of variability in mean CAL (adjusted R2 = 0.164; p < 0.001). Older patients had higher odds for an increased mean CAL (ß = 0.266; p = 0.001), as well as patients smoking or formerly smoking (ß = 0.305; p < 0.001) whereas visiting a dental medicine doctor once a year or more often was associated with a decreased mean CAL (ß = - 0.182; p = 0.02). CONCLUSIONS: OSA was associated with severe stages of periodontitis along with increased age, smoking, low frequency of dental visits, and poor oral hygiene. CLINICAL RELEVANCE: Screening for periodontitis is recommended for patients with more severe forms of OSA.

Regulation of proliferation in developing human tooth germs by MSX homeodomain proteins and cyclin-dependent kinase inhibitor p19INK4d.

Before the secretion of hard dental tissues, tooth germs undergo several distinctive stages of development (dental lamina, bud, cap and bell). Every stage is characterized by specific proliferation patterns, which is regulated by various morphogens, growth factors and homeodomain proteins. The role of MSX homeodomain proteins in odontogenesis is rather complex. Expression domains of genes encoding for murine Msx1/2 during development are observed in tissues containing highly proliferative progenitor cells. Arrest of tooth development in Msx knockout mice can be attributed to impaired proliferation of progenitor cells. In Msx1 knockout mice, these progenitor cells start to differentiate prematurely as they strongly express cyclin-dependent kinase inhibitor p19INK4d. p19INK4d induces terminal differentiation of cells by blocking the cell cycle in mitogen-responsive G1 phase. Direct suppression of p19INK4d by Msx1 protein is, therefore, important for maintaining proliferation of progenitor cells at levels required for the normal progression of tooth development. In this study, we examined the expression patterns of MSX1, MSX2 and p19INK4d in human incisor tooth germs during the bud, cap and early bell stages of development. The distribution of expression domains of p19INK4d throughout the investigated period indicates that p19INK4d plays active role during human tooth development. Furthermore, comparison of expression domains of p19INK4d with those of MSX1, MSX2 and proliferation markers Ki67, Cyclin A2 and pRb, indicates that MSX-mediated regulation of proliferation in human tooth germs might not be executed by the mechanism similar to one described in developing tooth germs of wild-type mouse.