Does information about MIH on dental homepages in Germany offer high quality? A systematic search and analysis.

PURPOSE: The internet is increasingly used to seek health information. A dental condition of increasing concern and public interest is molar incisor hypomineralisation (MIH), why we evaluated the information quality of German dentists 'websites on the topic of MIH. METHODS: A systematic search was performed by two independent investigators using three search engines. The information content of websites on MIH and technical, functional aspects, overall quality, and risk of bias were assessed using validated instruments (LIDA, DISCERN). Practice-related characteristics (practice type, specialization, setting, number and mean age of dentists) were recorded, and associations of these characteristics with websites' overall quality were explored using multivariable linear regression modelling. RESULTS: 70 sites were included. 52% were multipractices in urban areas (49%). The most common age group was middle-aged individuals (41-50 years). The average number of dentists/practice was 2.5. The majority met more than 50% of the DISCERN and LIDA criteria (90%, 91%). The MIH definition was frequently used (67%), MIH symptoms were described (64%), and 58% mentioned therapies. The prevalence of MIH was mentioned less frequently (48%). MIH example photographs were rarely shown (14%). In multivariable analysis, most practice-related factors were not significant for overall site quality. Only chain practices had slightly higher quality in this regard (2.2; 95% CI of 0.3-4.1). CONCLUSIONS: MIH is mentioned on a large proportion of dentists' websites. Overall technical, functional, and generic quality was high. Risk of bias is limited. While most websites provided a basic definition of MIH and its symptoms, important information for patients was missing.

Association, prediction, generalizability: Cross-center validity of predicting tooth loss in periodontitis patients.

OBJECTIVES: To predict patients' tooth loss during supportive periodontal therapy across four German university centers. METHODS: Tooth loss in 897 patients in four centers (Kiel (KI) n = 391; Greifswald (GW) n = 282; Heidelberg (HD) n = 175; Frankfurt/Main (F) n = 49) during supportive periodontal therapy (SPT) was assessed. Our outcome was annualized tooth loss per patient. Multivariable linear regression models were built on data of 75 % of patients from one center and used for predictions on the remaining 25 % of this center and 100 % of data from the other three centers. The prediction error was assessed as root-mean-squared-error (RMSE), i.e., the deviation of predicted from actually lost teeth per patient and year. RESULTS: Annualized tooth loss/patient differed significantly between centers (between median 0.00 (interquartile interval: 0.00, 0.17) in GW and 0.09 (0.00, 0.19) in F, p = 0.001). Age, smoking status and number of teeth before SPT were significantly associated with tooth loss (p < 0.03). Prediction within centers showed RMSE of 0.14-0.30, and cross-center RMSE was 0.15-0.31. Predictions were more accurate in F and KI than in HD and GW, while the center on which the model was trained had a less consistent impact. No model showed useful predictive values. CONCLUSION: While covariates were significantly associated with tooth loss in linear regression models, a clinically useful prediction was not possible with any of the models and generalizability was not given. Predictions were more accurate for certain centers. CLINICAL RELEVANCE: Association should not be confused with predictive value: Despite significant associations of covariates with tooth loss, none of our models was useful for prediction. Usually, model accuracy was even lower when tested across centers, indicating low generalizability.

Long-term tooth retention in periodontitis patients in four German university centres.

OBJECTIVES: In this retrospective study, we compared tooth loss between patients receiving periodontal therapy (PT) in four German university centres, stratified according to periodontal treatment phase. MATERIALS AND METHODS: Overall, 896 patients (Kiel (KI) n = 391; Greifswald (GW) n = 282; Heidelberg (HD) n = 174; Frankfurt a.M. (F) n = 49) were examined initially (T0), after active periodontal therapy (APT, T1) and after supportive periodontal therapy (SPT, T2). Descriptive analyses and multivariable negative binomial regression models were performed. RESULTS: Follow-up periods differed significantly between the centres, ranging between 6.7 ±â€¯3.0 (GW) and 18.2 ±â€¯5.5 (KI) years (p < 0.001). At T0, age, gender, smoking and diabetes showed notable regional distinctions (p < 0.001). However, the number of teeth per patient was similar (between 24.0 ±â€¯4.6 (F) and 24.5 ±â€¯4.1 (HD); p = 0.27). During PT, the number of extracted teeth differed significantly between centres, with greater differences during SPT (0.9 ±â€¯1.8 (GW) to 2.3 ±â€¯2.8 (KI), p < 0.001) compared to APT (0.4 ±â€¯0.9 (F) to 1.0 ±â€¯2.1 (KI), p = 0.02). Annual tooth loss during SPT remained low in all centres (between 0.10 ±â€¯0.14 (F) to 0.15 ±â€¯0.30 (HD), p < 0.001). CONCLUSION: Within the limitation of the study, PT leads to a low risk of tooth loss in all university centres irrespective of patients' baseline characteristics. CLINICAL RELEVANCE: Within the limitations of this retrospective investigation, long-term tooth retention seems to be feasible for most patients, as long as a systematic and structured treatment approach is applied.

Smoking Modifies the Genetic Risk for Early-Onset Periodontitis.

Periodontitis has low-prevalence, highly severe disease manifestations with an early onset and rapid progression. The diagnosis is based on severe destruction of the alveolar bone in adolescents and young adults. Genetic susceptibility variants and smoking are well-established risk factors, but their interactions in modifying disease susceptibility have not been studied. We aimed to identify genetic risk variants of early-onset periodontitis that unmask their effects on tobacco smoke exposure. To this end, we analyzed 79,780,573 common variants in 741 northwest Europeans diagnosed to have >30% bone loss at >2 teeth before 35 y of age, using imputed genotypes of the OmniExpress BeadChip. Never versus ever smokers were compared in a logistic regression analysis via a case-only approach. To explore the effect of tobacco smoke on the expression of the G×S-associated genes, cultures of primary gingival fibroblasts (n = 9) were exposed to cigarette smoke extract, and transcripts were quantified by reverse transcription polymerase chain reaction. We identified 16 loci for which our analysis suggested an association with G×S increased disease risk (P < 5 × 10-5). Nine loci had previously been reported to be associated with spirometric measures of pulmonary function by an earlier G×S genome-wide association study. Genome-wide significant cis expression quantitative trait loci were reported for G×S-associated single-nucleotide polymorphisms at ST8SIA1 and SOST, indicating a causal role of these genes in tobacco-related etiopathology. Notably, SOST is a negative regulator of bone growth, and ST8SIA1 has a role in tissue remodeling. Cigarette smoke extract significantly altered the expression of 2 associated genes: SSH1 (P = 5 × 10-07), which is required for NF-κB activation and innate immune responses to bacterial invasion, and ST8SIA1 (P = 0.0048). We conclude that the genetic predisposition to early-onset periodontitis is in part triggered by smoking and that tobacco smoke directly affects the expression of genes involved in bone homeostasis, tissue repair, and immune response.

Evaluating Modeling and Validation Strategies for Tooth Loss.

Prediction models learn patterns from available data (training) and are then validated on new data (testing). Prediction modeling is increasingly common in dental research. We aimed to evaluate how different model development and validation steps affect the predictive performance of tooth loss prediction models of patients with periodontitis. Two independent cohorts (627 patients, 11,651 teeth) were followed over a mean ± SD 18.2 ± 5.6 y (Kiel cohort) and 6.6 ± 2.9 y (Greifswald cohort). Tooth loss and 10 patient- and tooth-level predictors were recorded. The impact of different model development and validation steps was evaluated: 1) model complexity (logistic regression, recursive partitioning, random forest, extreme gradient boosting), 2) sample size (full data set or 10%, 25%, or 75% of cases dropped at random), 3) prediction periods (maximum 10, 15, or 20 y or uncensored), and 4) validation schemes (internal or external by centers/time). Tooth loss was generally a rare event (880 teeth were lost). All models showed limited sensitivity but high specificity. Patients' age and tooth loss at baseline as well as probing pocket depths showed high variable importance. More complex models (random forest, extreme gradient boosting) had no consistent advantages over simpler ones (logistic regression, recursive partitioning). Internal validation (in sample) overestimated the predictive power (area under the curve up to 0.90), while external validation (out of sample) found lower areas under the curve (range 0.62 to 0.82). Reducing the sample size decreased the predictive power, particularly for more complex models. Censoring the prediction period had only limited impact. When the model was trained in one period and tested in another, model outcomes were similar to the base case, indicating temporal validation as a valid option. No model showed higher accuracy than the no-information rate. In conclusion, none of the developed models would be useful in a clinical setting, despite high accuracy. During modeling, rigorous development and external validation should be applied and reported accordingly.

Effect of total sonicated Aggregatibacter actinomycetemcomitans fragments on gingival stem/progenitor cells.

BACKGROUND: Aggregatibacter-actinomycetemcomitans (A.actinomycetemcomitans) are strongly associated with localized-aggressive-periodontitis (LAgP). The study's aim was to test for the first time the effect of total sonicated A.actinomycetemcomitans-bacterial-fragments on gingival mesenchymal stem/progenitor cells' (G-MSCs) proliferation and regenerative gene expression in-vitro. MATERIAL AND METHODS: G-MSCs were isolated, characterized, expanded and stimulated by total sonicated A.actinomycetemcomitans-bacterial-fragments (0 (negative-control), 15, 60, 120 and 240µg/ml; serovar-b; n=6/group). Cellular proliferation and NF-κß (NFKB1), Alkaline Phosphatase (ALPL), Collagen-I (COL1A1), Collagen-III (COL3A1), Osteonectin (SPARC) and Osteopontin (SPP1) m-RNA expression were assessed via reverse-transcription-polymerase-chain-reaction (RT-PCR) at 24, 48 and 72 hours and CFUs-ability evaluated at twelve days. RESULTS: G-MSCs demonstrated stem/progenitor cells' characteristics. A.actinomycetemcomitans-bacterial-fragments (up to 72 hours) resulted in marked G-MSCs' proliferation over-time (p<0.001) and elevated NFKB1 (p=0.017), COL1A1 (p=0.025), SPARC (p=0.025), decreased ALPL (p=0.017), with no significant differences for COL3A1 and SPP1 expression or stimulation times (p>0.05; Friedman-test). Longer-term stimulation for twelve days reduced G-MSCs' CFUs. CONCLUSIONS: Sonicated A.actinomycetemcomitans-bacterial-fragments' exert beneficial short-term effects on G-MSCs' proliferative and non-mineralized tissue forming aptitude. Results shed new light on the importance of periodontal treatment for LAgP patients, using power driven sonic/ultrasonic devices, which, in addition to reducing the subgingival microbial load, produces cell-stimulatory A.actinomycetemcomitans-bacterial-fragments, with positive attributes on tissue reparative/regenerative responses of tissue resident stem/progenitor cells in their niche.

Bristle splaying and its effect on pre-existing gingival recession-a 12-month randomized controlled trial.

OBJECTIVE: The link between bristle splaying and gingival recession is unclear. METHODS: In a 12-month, parallel group, randomized, controlled clinical trial, 110 systemically healthy participants with pre-existing gingival recessions (pre-GR) were assigned to brush their teeth with either a manual (MT) or a powered toothbrush (PT). Every 3 months, toothbrushes and brush heads were replaced. Wear was measured using the Bristle-Splaying-Index (BSI), matched between groups and correlated to the change of pre-GR. RESULTS: Data from 109 subjects (PT, 55; MT, 54) were analyzed. The overall mean BSI was found to be significantly lower (p < 0.001) in the PT group (median 5.5; second and third quartile 1.9-10.0) as compared to the MT group (21.5; 15.0-30.5). After 12 months, pre-GR decreased significantly in the PT group (∆0.2 ± 0.1 mm; p < 0.001) and remained stable in the MT group (∆0.1 ± 0.1 mm; p > 0.05). In the MT group, higher BSI values were associated with a higher risk for increasing or stable recession over 12 months: odds ratio (95 % CI) = 27.9 (1.7; 452.9); p = 0.019. CONCLUSION: After a mean using time of 3 months, the PT group demonstrated a lower BSI than the MT group, and the greater bristle splaying was associated with a higher risk of increased (or stable) GR in subjects using a MT but not a PT. CLINICAL RELEVANCE: Compared to a manual toothbrush, powered toothbrushes seem to be utilized with less force and can be considered safe to use in patients with pre-existing gingival recession.

Investigation of sex-specific effects of apolipoprotein E on severity of EAE and MS.

BACKGROUND: Despite pleiotropic immunomodulatory effects of apolipoprotein E (apoE) in vitro, its effects on the clinical course of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS) are still controversial. As sex hormones modify immunomodulatory apoE functions, they may explain contentious findings. This study aimed to investigate sex-specific effects of apoE on disease course of EAE and MS. METHODS: MOG(35-55) induced EAE in female and male apoE-deficient mice was assessed clinically and histopathologically. apoE expression was investigated by qPCR. The association of the MS severity score (MSSS) and APOE rs429358 and rs7412 was assessed across 3237 MS patients using linear regression analyses. RESULTS: EAE disease course was slightly attenuated in male apoE-deficient (apoE (-/-) ) mice compared to wildtype mice (cumulative median score: apoE (-/-) = 2 [IQR 0.0-4.5]; wildtype = 4 [IQR 1.0-5.0]; n = 10 each group, p = 0.0002). In contrast, EAE was more severe in female apoE (-/-) mice compared to wildtype mice (cumulative median score: apoE (-/-) = 3 [IQR 2.0-4.5]; wildtype = 3 [IQR 0.0-4.0]; n = 10, p = 0.003). In wildtype animals, apoE expression during the chronic EAE phase was increased in both females and males (in comparison to naïve animals; p < 0.001). However, in MS, we did not observe a significant association between MSSS and rs429358 or rs7412, neither in the overall analyses nor upon stratification for sex. CONCLUSIONS: apoE exerts moderate sex-specific effects on EAE severity. However, the results in the apoE knock-out model are not comparable to effects of polymorphic variants in the human APOE gene, thus pinpointing the challenge of translating findings from the EAE model to the human disease.

Spatter contamination in dental practices--how can it be prevented?

UNLABELLED: Infectious diseases endanger all dental personnel during treatment, especially when spatter and aerosols are produced. Therefore, there is a strong need for better infection control principles during all treatments. The purpose of this in-vitro pilot study was to measure the environmental spatter contamination through a fluorescence technique. Scaling was performed using different power-driven devices and high-volume evacuation combined with a newly developed cannula (PS), standard suction cannulas (STS) and saliva ejectors (CDS). MATERIAL AND METHODS: One sonic (AIR) and two ultrasonic devices (TIG, VEC) were utilized to remove biofilm from 168 artificial teeth in a manikin head. Teeth were scaled for 120s supra- or subgingivally. The spatter contamination of an area of 1.5m2 around the manikin head was assessed. RESULTS AND CONCLUSIONS: The contaminated area (%) was significantly different for the AIR (median [25th; 75th percentiles]: 2.5 [1.16; 6.05]) versus TIG (0.25 [0.18; 0.88]) and VEC (0.08 [0.06; 0.1]) (p<0.001). Irrespective of the instrument, subgingival scaling led to a less contaminated area (0.18 [0.07; 1.05]) than supragingival scaling (0.34 [0.1; 2.24]) (p < 0.001). High-volume evacuation combined with STS (0.17 [0.07; 1.04]) and PS (0.18 [0.07; 1.14]) reduced the contamination similarly (p=0.302) and was more effective compared to CDS (1.01 [0.12-5.78]) (p<0.001; p=0.002). Beside the limitation of an in-vitro investigation, it can be conclude that only high-volume evacuation with an adequately calibrated cannula is capable of significantly reducing the amount of spatter contamination produced during power-driven scaling.