Effects of oxidized LDL versus IL-1ß/TNF-ɑ/INFÉ£ on human gingival mesenchymal stem cells properties.

AIMS: Oxidized low-density lipoprotein (oxLDL) is an important player in the course of metabolic inflammatory diseases. oxLDL was identified in the gingival crevicular fluid, denoting possible associations between oxLDL-induced inflammation and periodontal disease. The current investigation compared for the first-time direct effects of oxLDL to a cytokine cocktail of IL-1ß/TNF-ɑ/INF-γ on gingival mesenchymal stem cells' (G-MSCs) attributes. METHODS: Human third passage G-MSCs, isolated from connective tissue biopsies (n = 5) and characterized, were stimulated in three groups over 7 days: control group, cytokine group (IL-1ß[1 ng/mL], TNF-α[10 ng/mL], IFN-γ[100 ng/mL]), or oxLDL group (oxLDL [50 µg/mL]). Next Generation Sequencing and KEGG pathway enrichment analysis, stemness gene expression (NANOG/SOX2/OCT4A), cellular proliferation, colony-formation, multilinear potential, and altered intracellular pathways were investigated via histochemistry, next-generation sequencing, and RT-qPCR. RESULTS: G-MSCs exhibited all mesenchymal stem cells' characteristics. oxLDL group and cytokine group displayed no disparities in their stemness markers (p > .05). Next-generation-sequencing revealed altered expression of the TXNIP gene in response to oxLDL treatment compared with controls (p = .04). Following an initial boosting for up to 5 days by inflammatory stimuli, over 14 day, cellular counts [median count ×10-5 (Q25/Q75)] were utmost in control - [2.6607 (2.0804/4.5357)], followed by cytokine - [0.0433 (0.0026/1.4215)] and significantly lowered in the oxLDL group [0.0274 (0.0023/0.7290); p = .0047]. Osteogenic differentiation [median relative Ca2+ content(Q25/Q75)] was significantly lower in cytokine - [0.0066 (0.0052/0.0105)] compared to oxLDL - [0.0144 (0.0108/0.0216)] (p = .0133), with no differences notable for chondrogenic and adipogenic differentiation (p > .05). CONCLUSIONS: Within the current investigation's limitations, in contrast to cytokine-mediated inflammation, G-MSCs appear to be minimally responsive to oxLDL-mediated metabolic inflammation, with little negative effect on their differentiation attributes and significantly reduced cellular proliferation.

Domains, competences and learning outcomes for undergraduate education in periodontology.

AIM: This review is intended to adapt the current conceptual framework in dental education based on four domains to propose a set of competences, learning outcomes and methods of teaching, learning and assessment for undergraduate education in periodontology. REVIEW: Based on the current framework of competences and learning outcomes recommended by the Association for Dental Education in Europe (ADEE), undergraduate education in periodontology has been updated using the classification and clinical practice guidelines for the diagnosis and treatment of periodontal and peri-implant diseases. CONCLUSIONS: Specific learning outcomes have been proposed within each competence area, that is in Domain I (n = 10), Domain II (n = 13), Domain III (n = 33) and Domain IV (n = 12). Teaching methods and learning activities based on the different dimensions of the cognitive process have been proposed. Additionally, 10 key learning outcomes have been proposed as exit outcomes, which implies their accomplishment within the final assessment of any graduating student.

Long-term effect of simulated five years professional mechanical biofilm removal on the luting gap of ceramic restorations.

BACKGROUND: Achieving sufficient professional mechanical biofilm removal (PMPR) can be challenging in supportive periodontal therapy (SPT), particularly in patients with prosthetic restorations. This experimental study aimed to simulate five years of SPT with periodic PMPR near the luting gap of ceramic restorations using a rubber cup with polishing paste (RCP), air polishing with two different low-abrasive powders (LAPA-1: glycine powder, LAPA-2: erythritol powder), and non-professional mechanical cleaning (control group) to measure the extent of volume loss in the luting gap after baseline (∆V = Vbaseline-V1-5; in µm3). METHODS: Two operators randomly performed PMPR ten times for thirty seconds on one of four sides of 30 crown replicas fixed with glass-ionomer cement (CGIZ: n = 15) or adhesive bonding (CAB: n = 15). The replicas were separated in a template during PMPR, and afterward, cleaned for five seconds per side with a sonic brush under flowing water. The artificial aging process between two PMPRs simulated a 5-year SPT with two PMPRs per year. Profilometric measurements were performed at baseline and after each second PMPR to obtain the mean change of ∆V. The statistical evaluation of the data was carried out using nonparametric tests with Bonferroni correction applied for multiple tests. RESULTS: Ninety-six out of 120 sides could be included in the analysis. PMPR methods showed a loss of substance in the luting gap with a ∆V (mean(standard deviation)) of -4.35 × 106(4.8 × 106)µm3 versus 8.79 × 104(1.05 × 106)µm3 for control at V5 (p ≤ 0.001). No significant differences of ∆V1-5 values could be identified in the control (p > 0.05), whereat all PMPRs showed a significant increasing loss of substance per simulated year (p ≤ 0.001). Intergroup comparison identified LAPA-1 as having the highest significant loss of substance determined on CAB (∆V: -1.05 × 107 (7,2 × 106) µm3), followed by LAPA-2 on CAB (∆V: -6.29 × 106 (4,24 × 106) µm3), LAPA-1 on CGIZ (∆V: -4.15 × 106 (3,25 × 106) µm3), LAPA-2 on CGIZ (∆V: -3.0 × 106 (2,23 × 106) µm3), RCP on CAB (∆V: -1.86 × 106 (2,23 × 106) µm3) and CGIZ (∆V: -1.2 × 106 (1,31 × 106) µm3; p ≤ 0.001)). CONCLUSIONS: Within study limitations, all PMPRs caused a significantly higher loss of substance in the luting gap versus control without professional intervention, with the highest values in the CAB group for LAPA-1, LAPA-2 and RCP. Similar findings were observed for CGIZ, although the loss values were lower.

New design of interdental rubber picks - does the archimedean screw design bring an improvement for experimental cleaning efficacy and force?

BACKGROUND: Up to date, interdental brushes (IDB) are the first choice for interdental cleaning because of their cleaning efficacy. Cylindrical ones must be selected individually according to the size/morphology of the interdental area (IDR), whereas conical ones cover a larger variability of IDR. However, there is a trend on the part of patients towards interdental rubber picks (IRP) which are in general conically shaped, and which seem to be linked with lower cleaning efficacy. A new IRP with an Archimedes´ screw design was developed to overcome this limitation. Therefore, the in vitro study aimed to measure the experimental cleaning efficacy (ECE) and force (ECF) during interdental use of IDBs versus the new IRP type. METHODS: Three IRPs with different tapers (PHB angled: 0.039, PHB straight S: 0.027, Vitis straight M: 0.045; all Flexipicks, Dentaid, Cerdanyola del Vallès, Spain) were compared to one IDB (Interprox micro PHD 0.9, Dentaid, Cerdanyola del Vallès, Spain). IDR were reproduced by a 3D-printer (Form2, Formlabs Sommerville, MA, USA) according to human teeth and matched to equivalent pairs (isosceles triangle, concave, convex) in three different diameters (1.0 mm,1.1 mm,1.3 mm). Covered with simulated biofilm, pre-/ post-brushing situations of IDR (standardized, computer-aided ten cycles) were photographed and quantified by digital image subtraction to calculate ECE [%]. ECF were registered with a load cell [N]. Statistically significant differences were detected using the Mann-Whitney-U-test and the Kruskal-Wallis-test with Bonferroni correction for multiple testing. RESULTS: Overall, the ECE (mean ± SD) was higher for IDB micro 0.9 (45.95 ± 11.34%, p < 0.001) compared to all IRPs (PHB angled: 25.37 ± 15.29%; PHB straight: 22.28 ± 16.75%; Vitis straight: 25.24 ± 12.21%; p ≤ 0.001), whereat best ECE was achieved in isosceles triangle IDR of 1.0-1.1 mm (IDB micro 0.9: 70.7 ± 7.7%; PHB angled S: 57.30 ± 4.43%; p < 0.001). The highest ECF occurred for Vitis straight M with 2.11 ± 0.46 N, while IDB micro 0.9 showed lowest ECF values (0.64 ± 0.14 N; p < 0.001). CONCLUSIONS: IRP with an Archimedes´ screw design and a higher taper were associated with advanced ECE but also higher ECF, nevertheless, ECE didn't reach the cleaning efficacy of conventional IDBs.

Effect of a powered and a manual toothbrush in subjects susceptible to gingival recession: A 36-month randomized controlled clinical study.

OBJECTIVE: The objective of this long-term clinical study was to evaluate the influence of a newly developed powered toothbrush (PT) on the size and number of pre-existing gingival recessions (GR) in comparison to a manual toothbrush (MT). METHODS: This was a prospective, single-blind, parallel-group, randomized controlled clinical study. Participants without periodontitis, but with at least two teeth (index teeth) showing GR ≥2 mm were randomized to brush either twice daily with a MT or with a PT with a linear magnetic drive causing the round brush head to produce gentle micro vibrations along with oscillating-rotating movements. Primary outcome parameter was the mean change of GR at the index teeth over 36 months. RESULTS: Totally 87 out of 92 participants completed the study (MT/PT: n = 42/n = 45). At the 36-month evaluation the mean (standard deviation) change of GR at index teeth differed significantly between MT 0.17 (0.77) and PT -0.10 (0.63) (p = 0.013). Furthermore, the amount of GR sites which improved ≥1 mm or remained stable during the study period did not differ between MT and PT, but the number of sites worsened ≥1 mm was significantly in favour for PT (MT 23 (25.5%) versus PT 10 (10.6%); p = 0.009). A binary logistic regression identified tooth type (OR = 2.991 for pre-/molar (1.096 [95% CI 1.002-8.933]; p = 0.050)) and manual brushing (OR = 3.341 (1.206 [95% CI 1291-8648]; p = 0.013)) as risk factors for recession impairment at the index teeth. There were no differences between groups for adverse events. CONCLUSION: In a population with pre-existing gingival recessions and consequently a high risk of developing further recession the PT seems to be favourable with regard to further development of GR.

Tooth loss in periodontally treated patients: A registry- and observation-based analysis.

AIM: According to retrospective clinical studies, periodontal treatment retains teeth. However, evidence on the effectivity of periodontal treatment stemming from the general population is lacking. MATERIALS AND METHODS: We analysed data of periodontally treated patients from routine data of a major German national health insurance (BARMER-MV; sub-sample of the Federal State of Mecklenburg-Vorpommern) and from a clinical cohort (Greifswald Approach to Individualized Medicine, GANI_MED), as well as periodontally untreated and treated participants of the Study of Health in Pomerania (SHIP-TREND) with either ≥2 or ≥4 teeth with pocket depths ≥4 mm. Yearly tooth loss (YTL) estimates and incidence rates were evaluated. RESULTS: For moderately to severely affected groups, YTL and incidence rates were higher in BARMER-MV patients (0.35 and 0.18, respectively) than in untreated SHIP-TREND controls (0.19 and 0.08, respectively). In line, treated SHIP-TREND participants exhibited higher YTL rates than untreated SHIP-TREND controls (0.26 vs. 0.19). For severely affected groups, results with respect to tooth loss were inconclusive regarding the beneficial effects of periodontal treatment conducted either in the university (GANI_MED data) or in the general practice. CONCLUSION: Until 2021, periodontal treatment performed in German general dental practices within the national health insurance system was probably not efficient in retaining more teeth in the short- to mid-term. Since reimbursement schemes were changed in 2021 and now cover periodontal treatment to a much larger extent, the future will show whether these new reimbursement codes will improve the quality of periodontal treatment and whether they will lead to more long-term tooth retainment.

Influence of flow rate and different size of suction cannulas on splatter contamination in dentistry: results of an exploratory study with a high-volume evacuation system.

OBJECTIVES: SOPs recommend high-volume evacuation (HVE) for aerosol-generating procedures (AGPs) in dentistry. Therefore, in the exploratory study, the area of splatter contamination (SCON in %) generated by high-speed tooth preparation (HSP) and air-polishing (APD) was measured when different suction cannulas of 6 mm diameter (saliva ejector (SAE)), 11 mm (HC11), or 16 mm (HC16) were utilized versus no-suction (NS). MATERIALS AND METHODS: Eighty tests were performed in a closed darkened room to measure SCON (1m circular around the manikin head (3.14 m2) via plan metrically assessment through fluorescence technique. HSP (handpiece, turbine (Kavo, Germany)) or APD (LM-ProPowerTM (Finland), Airflow®-Prophylaxis-Master (Switzerland)) for 6 min plus 5 s post-treatment were performed either without suction or with low-flow (150 l/min for SAE) or high-flow rate (250 l/min/350 l/min for HC11/HC16) suction. All tests were two-tailed (p≤0.05, Bonferroni corrected for multi-testing). RESULTS: Irrespective the AGP, SCON was higher for NS (median [25th; 75th percentiles]: 3.4% [2.6; 5.4]) versus high-flow suction (1.9% [1.5; 2.5]) (p=0.002). Low-flow suction (3.5% [2.6; 4.3]) versus NS resulted in slightly lower but not statistically significantly lower SCON (p=1.000) and was less effective than high-flow suction (p=0.003). Lowest contamination values were found with HC16 (1.9% [1.5; 2.5]; p≤0.002), whereat no significant differences were found for HC11 (2.4% [1.7; 3.1]) compared to SAE (p=0.385) or NS (p=0.316). CONCLUSIONS: Within study's limitations, the lowest splatter contamination values resulted when HC16 were utilized by a high-flow rate of ≥250 l/min. CLINICAL RELEVANCE: It is strongly recommended to utilize an HVE with suction cannulas of 16mm diameter for a high-flow rate during all AGPs and afterwards also to disinfect all surface of patients or operators contacted.

Periodontal maintenance: individual patient responses and discontinuations.

AIM: There is a lack of data on long-term impact of different psychological variables on periodontitis. Aim of the current study was to investigate the impact of psychological factors in patients with chronic periodontitis (CP; according to the 1999 Classification of Periodontal Diseases) to explain adherence to or discontinuation of supportive periodontal therapy (SPT) in a university setting. METHODS: A sample of n = 119 patients were examined in a questionnaire-based, cross-sectional survey. All patients had received active periodontal treatment (APT) and were reevaluated in a university setting (Kiel) before 2016 [T1: start SPT]. Patients who showed sufficient adherence to SPT of ≥ 2 years (maximum ± 6 months of deviation between SPT intervals, last visit and questionnaire at T2) were assigned to the adherence group (AG: n = 58), or, if they interrupted SPT or stopped treatment altogether, to the non-adherence group (NAG: n = 61). In addition to dental parameters, we assessed socio-demographic, treatment-related (critical attitudes/complaints), dental as well as psychological variables (especially psychological attachment, but also dental fear, patient participation style, personality functioning) and examined between-group differences as well as possible mediating factors of non-adherence to treatment continuation. RESULTS: For both groups we found similar average observation time (NAG/AG: 15.9(8.9)/14.9(10.6)years). There were significant differences in age, critical attitudes, dental fear, and patient participation style between the groups. With the help of exploratory sequential mediation models, we found a significant indirect pathway of the impact of attachment anxiety on discontinuation of treatment mediated through dental fear and number of critical attitudes/complaints. CONCLUSION: Considering the limitations, dentists should be aware of personality-related risk-factors such as attachment anxiety as well as their interplay with levels of dental fear and critical attitudes which may influence adherence to SPT. TRIAL REGISTRATION: The clinical trial was retrospectively registered in the DRKS-German Clinical Trials Register ( https://www.drks.de ) with registration DRKS00030092 (26/08/2022).

The influence of artificial saliva on the cleaning force of interdental rubber picks: an in-vitro comparison.

BACKGROUND: The familiar aids for interdental cleaning such as dental floss or interdental brushes (IDB) are often associated with difficult handling or an increased potential for trauma. Interdental picks (IRP), which have no metal core and silicone flaps instead of nylon brushes, offer the alternative. However, in-vitro studies found a lower cleaning effectiveness combined with higher forces for cleaning compared with conventional IDBs. The aim of this in-vitro study was to measure the experimental cleaning forces (ECF) using IRP with versus without an artificial saliva (AS; GUM Hydral, Sunstar Suisse SA, Etoy, Switzerland). METHODS: The test set-up was developed to investigate the cleaning of 3D-printed interdental area (IDR) mimicking human teeth (Form 2, Formlabs Sommerville, MA, USA) under standardized conditions. Three different morphologies (isosceles triangle, convex, concave) and three different sizes (1.0 mm,1.1 mm,1.3 mm) were used. Two different IRPs (GUM Soft-picks Advanced: SPA versus GUM Soft-picks Advanced Plus: SPA+, Sunstar Suisse SA, Etoy, Switzerland) in three sizes (small, regular, large), were used with versus without AS. ECF during ten cleaning cycles were recorded by a load cell [N]. RESULTS: Using AS leaded to significant lower values for ECF than without (1.04 ± 0.66 N versus 1.97 ± 1.01 N, p < 0.001). In general, a lower ECF was recorded for convex IDR compared to isosceles triangle and concave morphologies (p < 0.001) as well as for gap sizes of 1.3 mm compared to the smaller sizes (p < 0.001). For SPA+ we found significantly higher force values than for SPA (1.67 ± 0.93 N versus 1.31 ± 0.97 N, p < 0.001) independent of the use of AS. CONCLUSION: Within the study´s in-vitro limitations, we found AS reduced ECF of IRPs by half and allowed using larger diameters interdentally, which could be associated with (1) a higher cleaning effectiveness and (2) a higher acceptance e.g. of patients with dry mouth. This has to be confirmed by further clinical investigations.

Sex-specific genetic factors affect the risk of early-onset periodontitis in Europeans.

AIMS: Various studies have reported that young European women are more likely to develop early-onset periodontitis compared to men. A potential explanation for the observed variations in sex and age of disease onset is the natural genetic variation within the autosomal genomes. We hypothesized that genotype-by-sex (G × S) interactions contribute to the increased prevalence and severity. MATERIALS AND METHODS: Using the case-only design, we tested for differences in genetic effects between men and women in 896 North-West European early-onset cases, using imputed genotypes from the OmniExpress genotyping array. Population-representative 6823 controls were used to verify that the interacting variables G and S were uncorrelated in the general population. RESULTS: In total, 20 loci indicated G × S associations (P < 0.0005), 3 of which were previously suggested as risk genes for periodontitis (ABLIM2, CDH13, and NELL1). We also found independent G × S interactions of the related gene paralogs MACROD1/FLRT1 (chr11) and MACROD2/FLRT3 (chr20). G × S-associated SNPs at CPEB4, CDH13, MACROD1, and MECOM were genome-wide-associated with heel bone mineral density (CPEB4, MECOM), waist-to-hip ratio (CPEB4, MACROD1), and blood pressure (CPEB4, CDH13). CONCLUSIONS: Our results indicate that natural genetic variation affects the different heritability of periodontitis among sexes and suggest genes that contribute to inter-sex phenotypic variation in early-onset periodontitis.

Evaluation of a systematic digitized training program on the effectivity of subgingival instrumentation with curettes and sonic scalers in vitro.

OBJECTIVES: Whereas the key role of subgingival instrumentation in periodontal therapy is well known, the influence of operators' experience/training with different devices on treatment results is yet uncertain. Therefore, we assessed untrained undergraduate students, working on manikins, as to how effectively they learn to use curettes (GRA) and sonic scalers (AIR); hypothesizing that AIR will result in higher relative cleaning efficacy (RCE) than GRA. MATERIAL AND METHODS: Before baseline evaluation (T0), 30 operators (9 males, 21 females) received a 2-h theoretical lesson for both instruments, followed by a 12-week period with a weekly digitized training program for 45 min. During three sessions (T1-T3), the operators had to instrument six equivalent test teeth with GRA and AIR. At T0-T3, treatment time, proportion of removed simulated biofilm (RCE-b), and hard deposits (RCE-d) were measured. RESULTS: At T0, RCE-b was in mean(SD) 64.18(25.74) % for GRA, 62.25(26.69) % for AIR; (p = 0.172) and RCE-d 85.48(12.32) %/ 65.71(15.27) % (p < 0.001). At T3, operators reached highest RCE-b in both groups (GRA/AIR 71.54(23.90) %/71.75(23.05)%; p = 0.864); RCE-d GRA/AIR: 84.68(16.84) %/77.85(13.98) %; p < 0.001). Both groups achieved shorter treatment times after training. At T3, using curettes was faster (GRA/AIR 16.67(3.31) min/19.80(4.52) min; p < 0.001). CONCLUSIONS: After systematic digitized training, untrained operators were able to clean 70% of the root surfaces with curettes and sonic scalers. CLINICAL RELEVANCE: It can be concluded that a systematic digitized and interactive training program in manikin heads is helpful in the training of root surface debridement.

Results of an experimental study of subgingival cleaning effectiveness in the furcation area.

BACKGROUND: Sufficient biofilm removal in the furcation area (FA) is a major challenge in the clinical practice of supportive periodontal therapy. The aim of the present experimental study was to simulate subgingival cleaning of the FA using a powered scaler (sonic scaler (AIR), ultrasonic scaler (US)) for conventional mechanical debridement versus two air polishing with nonabrasive powder (LAPA-1: glycine powder, LAPA-2: erythritol powder) and different nozzles for supra-/subgingival cleaning for each device. METHODS: Seven trained and calibrated operators with ≥ 2 years each of professional experience in treating periodontitis used the instruments to clean 3D-printed replicas of six molars with through-and-through FA (four 3-rooted and two 2-rooted teeth) in a manikin head. AIR and US were used in the control group; air polishing instruments were used in the test group. For reproducible evaluation, the test teeth were separated vertically into two or three parts, illuminated with ultraviolet light, photographed and evaluated planimetrically. Treatment time (TrT, in s) and relative cleaning efficacy (RCE, in %) were measured. RESULTS: Overall, 3-rooted molars (RCE in the entire FA, 23.19 ± 20.98%) could be cleaned significantly less effectively than 2-rooted molars (53.04 ± 28.45%, p < 0.001), regardless of the instrument used. In the cleaning of the entire FA, significantly higher RCE values were achieved with conventional mechanical debridement (AIR/US: 46.04 ± 25.96%/39.63 ± 22.02%; AIR vs. US: p > 0.05) than with air polishing (LAPA-1/LAPA-2: 34.06 ± 29.48%/17.09 ± 18.85%; LAPA-1 vs. LAPA-2: p < 0.001) regardless of whether a supra- or subgingival cleaning nozzle used (p < 0.001). Only LAPA-1 with a subgingival nozzle showed RCE values comparable to those of US (41.07 ± 28.95% vs. 39.63 ± 22.02%, p > 0.05). TrT was longest for US (299.40 ± 120.69 s) and shortest for LAPA-1 with a supragingival nozzle (129.67 ± 60.92 s, p < 0.001). CONCLUSIONS: All of the examined instruments were effective to some degree in removing the simulated biofilm from the FA, but they differed substantially in cleaning efficacy. Only one air polishing device (LAPA-1) with a rigid subgingival nozzle was able to achieve RCE values similar to those of US. The current investigation confirmed that conventional mechanical debridement with powered scalers were most effective, but treatment took longer with these devices than air polishing.

The impact of psychological attachment on the relationship between periodontal health and dental fear in patients with versus without psoriasis: a questionnaire-based, cross-sectional study.

BACKGROUND: While there is increasing evidence for the relevance of psychosocial variables such as dental fear or psychological attachment in dentistry, much less is known about the mechanisms that determine the strength of those associations. One potential moderator is the occurrence of a comorbid chronic disease such as psoriasis, which is linked to relevant disease parameters such as periodontal inflammation. The aim of the study was to test a moderation model of the relationship between dental fear, psychological attachment and psoriasis on periodontal health. METHODS: A total of 201 patients (100 with psoriasis, 101 without psoriasis) were included in a questionnaire-based, cross-sectional study. Dental status was measured with the Community Periodontal Index (CPI), dental fear was measured with the Hierarchical Anxiety Questionnaire (HAQ), and psychological attachment was measured with the Relationship Questionnaire (RQ). In addition to the examination of main effects, bootstrapping-based analyses were conducted to test the moderating influence of psychological attachment on the association between CPI and dental fear, gain moderated by group (with vs. without psoriasis). RESULTS: Controlling for several covariates, higher CPI scores were associated with higher levels of dental fear only in individuals without psoriasis under conditions of higher levels of psychological attachment anxiety and lower levels of attachment avoidance. CONCLUSION: In individuals without psoriasis, psychological attachment can moderate the association between periodontal health and dental fear. This may provide a useful framework for reducing dental fear through interventions on the level of the dentist-patient relationship.

In vitro comparison of cleaning efficacy and force of cylindric interdental brush versus an interdental rubber pick.

BACKGROUND: Interdental brushes (IDB) are according to the actual evidence the first choice for cleaning interdental areas (IDR). Their size should be chosen individually according to the IDR morphology. However, interdental rubber picks (IRP) are appreciated better by the patients and are hence becoming more and more popular but the evidence regarding their efficacy is still limited. The aim of this in vitro study was to measure the experimental cleaning efficacy (ECE) and force (ECF) during the use of interdental brushes versus newer wireless types with rubber filaments (IRP), both fitted and non-fitted for different IDR. METHODS: The medium size of a conical IRP (regular, ISO 2) with elastomeric fingers versus four sizes (ISO 1, 2, 3, 4) of cylindric IDB with nylon filaments (all Sunstar Suisse SA, Etoy, Switzerland) were tested. Interdental tooth surfaces were reproduced by a 3D-printer (Form 2, Formlabs Sommerville, MA, USA) according to human teeth and matched to morphologically equivalent pairs (isosceles triangle, concave, convex) fitting to three different gap sizes (1.0 mm, 1.1 mm, 1.3 mm). The pre-/post brushing situations at IDR (standardized, computer aided ten cycles) were photographically recorded and quantified by digital image subtraction to calculate ECE [%]. ECF were registered with a load cell [N]. RESULTS: Overall, a higher ECE was recorded for IDB compared to IRP (58.3 ± 14.9% versus 18.4 ± 10.1%; p < 0.001). ECE significantly depended on the fitting of the IDB. ECE was significant higher in isosceles triangle compared to concave and convex IDR for both IDB and IRP (p ≤ 0.001). ECF was lower for IDB (0.6 ± 0.4N) compared to IRP (0.8 ± 0.5N; p ≤ 0.001). ECE in relation to ECF increases with smaller IDB. For IRP highest values of ECF were found in the smallest IDR. CONCLUSIONS: Within the limitations of an in vitro study, size fitted IDB cleaned more effectively at lower forces compared to conical IRP.

Contemporary practices for mechanical oral hygiene to prevent periodontal disease.

It is well established that dental plaque on teeth leads to gingivitis and periodontitis, and that several mechanical and chemical methods of plaque control can prevent gingivitis. The aim of the current review is to summarize and synthesize the available scientific evidence supporting practices for mechanical oral hygiene to prevent periodontal diseases. Evidence for contemporary practices of mechanical oral hygiene to prevent periodontal disease relies on studies of gingivitis patients. General recommendations concerning the ideal oral hygiene devices and procedures are still inconclusive. However, toothbrushing and interdental cleaning remain the mainstays of prevention of periodontal diseases. The primary approach requires individually tailored instruction for implementation of a systematic oral hygiene regimen.

Oral health-related quality of life impacts are low 27 years after periodontal therapy.

AIM: This pilot study assessed the oral-health-related quality of life (OHRQoL) after long-term periodontal therapy and explored OHRQoL differences along the 2018 Classification of Periodontal Diseases. METHODS: Sixty patients were examined before (T0) and after active periodontal therapy (APT/T1) and 32.0 ± 2.9 [range: 27-38] years of supportive periodontal therapy (SPT/T2). Periodontal diagnosis at T0 was assessed according to the 2018 Classification of Periodontal Diseases (stage 1/2/3/4: n = 1/3/44/13; grade n = A/B/C: 0/8/53). OHRQoL at T2 was measured using the Oral Health Impact Profile-G14 (OHIP-G14). Patients' Eichner's classification, accumulated tooth loss and treatment outcomes (SSO criteria) were assessed at T2. Generalized linear modelling (GLM) assessed associations between different factors and OHrQoL. RESULTS: Mean OHIP-G14 sum score was 3.7 (SD 5.6). There was no statistically significant association between OHIP-G14 and gender, stage, SSO criteria and tooth loss. OHIP-G14 was significantly lower in older patients (-0.2[-0.3;0] per year, p = .008), non-smokers (-5.9[-9.9;-1.9] p = .003) and former smokers (-7.4[-11.6;-3.2]; p < .001) versus current smokers, patients with Eichner class A1-B2 versus C2 (p < .05), sufficient adherence during SPT (-2.3[-4.6;-0.1], p = .044) versus insufficient ones. Patients with grade B (4.4[1.3;7.4]; p < .005) showed higher OHIP-G14 than those with grade C. CONCLUSION: A number of aspects, grounded in the initial diagnosis, the adherence to SPT, the resulting dentition, socio-demographic and behavioural covariates, were associated with good OHrQoL.

How to train periodontal endoscopy? Results of a pilot study removing simulated hard deposits in vitro.

OBJECTIVES: There is uncertainty regarding the benefits of periodontal endoscopy (PE) for subgingival instrumentation. Moreover, the influence of operators' experience and training with such a device on treatment results is unclear. Therefore, we compared in an in vitro study the use of PE for scaling and root planing (SRP) with the conventional non-surgical therapy, hypothesizing that using a PE allows to remove more simulated hard deposits than without (nPE), influenced by the operators' experience and training. MATERIAL AND METHODS: A sonic device and Gracey curettes were utilized by 11 operators (six dentists, five dental hygienists) in periodontitis manikins heads. The time required for treatment and the proportion of removed simulated hard deposits by SRP were measured. RESULTS: Using the PE led to a significant difference in removal of simulated hard deposits (%) (mean ± SD) irrespective of operators' experience (PE 90.78 ± 12.10% (range 58.80-100%); nPE 79.98 ± 22.15% (range 38.10-100%, p < 0.001)), sub-analyses for different tooth types demonstrated a significant difference in favor of PE for front teeth (p < 0.001) and in the upper jaw independent of the tooth type (p < 0.001). Comparison of treatment times for two quadrants with and without PE showed a significantly longer treatment time with PE (∆22.27 ± 17.98 mins, p <0.001). CONCLUSIONS: Within the present pilot study, the use of PE led to more removal of simulated hard deposits but was concomitantly related to more time and financial effort. Using PE was most beneficial in the front area. CLINICAL RELEVANCE: PE may provide additional benefits for the removal of hard deposits compared to traditional SRP. The beneficial effect of PE seems not to be influenced by operators experience nor by pocket probing depth.

Influence of motivation and a new digitized training program on undergraduate dental students during preclinical scaling training.

BACKGROUND: The current study evaluated whether a new digitized scaling training program (DTP: n = 30; supervisor-student-ratio 1:10) improves the performance of undergraduate dental student during a preclinical course in regard to two different instruments [sonic scalers (AIR) and Gracey curettes (GRA)] compared to a conventional training program (CTP: n = 19; supervisor-student-ratio 1:4). METHODS: All the participants received a two-hour lecture on both instruments, followed by a 12-week period with a weekly training program lasting 45 min (10 sessions); one group was supported by DTP. At the end of the training phase, all the participants performed the subgingival scaling of six equivalent test teeth using GRA and AIR. Treatment time, proportion of removed simulated biofilm (relative cleaning efficacy, RCE-b) and hard deposits (RCE-d) were recorded. By using a pseudonymized questionnaire with a 5-point Likert scale, self-assessment of scaling effort, handling, root surface roughness/destruction and effectiveness were evaluated. In addition, personal data such as age, gender, handedness, regularity of playing computer games/consoles and previous dental/technical or medical education were elevated and correlated with cleaning efficacy. RESULTS: The DTP participants showed higher effectiveness in RCE-b compared to those who used the CTP with GRA (71.54% vs. 67.23%, p = 0.004) and AIR (71.75% vs. 62.63%, p ≤ 0.001), and the DTP students were faster with both instruments (p ≤ 0.001). For RCE-d, there was no significant difference between the DTP and CTP groups (GRA p = 0.471; AIR p = 0.158), whereas DTP showed better RCE-d results with GRA versus AIR (84.68% vs. 77.85%, p < 0.001). According to the questionnaire, no significant differences were detected between the training groups in terms of self-assessment, handling, treatment time, root surface roughness/destruction or effectiveness of the instruments. The CTP group favored AIR compared to GRA regarding the fatigue effect. The CTP and playing computer games/consoles regularly was correlated with lower RCE-b, whereas previous education in medicine/dentistry was correlated with higher RCE-b values. CONCLUSIONS: Within the limitations of the study, the DTP with a reduced supervision effort compared to the CTP resulted in higher effectiveness and lower instrumentation time for removing simulated biofilms.

New experimental setup for the measurement of cleaning efficacy and force of interdental aids in 3D-reproduced interdental areas.

BACKGROUND: Interdental rubber picks (IRP) have become a frequent and convenient alternative for interdental cleaning. However, only little evidence exists supporting the effectiveness of newer designs available on the market. Therefore, a new in vitro model was evaluated to measure the experimental cleaning efficacy (ECE), as well as the force needed for insertion and during the use of IRP, with high reproducibility. METHODS: Five different sizes of commercially marketed IRP with elastomeric fingers (IRP-F) (GUM SOFT-PICKS® Advanced, Sunstar Deutschland GmbH, Schönau, Germany) or slats (IRP-S) (TePe EasyPick™, TePe D-A-CH GmbH, Hamburg, Germany) were tested. Interdental tooth surfaces were reproduced by a 3D-printer (Form 2, Formlabs Sommerville, MA, USA) according to human teeth and matched to morphologically equivalent pairs (isosceles triangle, concave, convex) fitting to different gap sizes (1.0 mm, 1.1 mm, 1.3 mm). The pre-/post brushing situations at interdental areas (standardized cleaning, computer aided ten cycles) were photographically recorded and quantified by digital image subtraction to calculate ECE [%]. Forces were registered with a load cell [N]. RESULTS: IRP-F have to be inserted with significant higher forces of 3.2 ± 1.8 N compared to IRP-S (2.0 ± 1.6 N; p < 0.001) independent of the size and type of artificial interdental area. During cleaning process IRP-S showed significantly lower values for pushing/pulling (1.0 ± 0.8 N/0.5 ± 0.4 N) compared to IRP-F (1.6 ± 0.8 N/0.7 ± 0.3 N; p < 0.001) concomitant to significantly lower ECE (19.1 ± 9.8 vs. 21.7 ± 10.0%, p = 0.002). Highest ECE was measured with largest size of IRP-F/IRP-S independent the morphology of interdental area. CONCLUSIONS: New interdental cleaning aids can be tested by the new experimental setup supported by 3D printing technology. Within the limitations of an in vitro study, IRP-F cleaned more effectively at higher forces compared to IRP-S.

A genome-wide association study identifies nucleotide variants at SIGLEC5 and DEFA1A3 as risk loci for periodontitis.

Periodontitis is one of the most common inflammatory diseases, with a prevalence of 11% worldwide for the severe forms and an estimated heritability of 50%. The disease is characterized by destruction of the alveolar bone due to an aberrant host inflammatory response to a dysbiotic oral microbiome. Previous genome-wide association studies (GWAS) have reported several suggestive susceptibility loci. Here, we conducted a GWAS using a German and Dutch case-control sample of aggressive periodontitis (AgP, 896 cases, 7,104 controls), a rare but highly severe and early-onset form of periodontitis, validated the associations in a German sample of severe forms of the more moderate phenotype chronic periodontitis (CP) (993 cases, 1,419 controls). Positive findings were replicated in a Turkish sample of AgP (223 cases, 564 controls). A locus at SIGLEC5 (sialic acid binding Ig-like lectin 5) and a chromosomal region downstream of the DEFA1A3 locus (defensin alpha 1-3) showed association with both disease phenotypes and were associated with periodontitis at a genome-wide significance level in the pooled samples, with P = 1.09E-08 (rs4284742,-G; OR = 1.34, 95% CI = 1.21-1.48) and P = 5.48E-10 (rs2738058,-T; OR = 1.28, 95% CI = 1.18-1.38), respectively. SIGLEC5 is expressed in various myeloid immune cells and classified as an inhibitory receptor with the potential to mediate tyrosine phosphatases SHP-1/-2 dependent signaling. Alpha defensins are antimicrobial peptides with expression in neutrophils and mucosal surfaces and a role in phagocyte-mediated host defense. This study identifies the first shared genetic risk loci of AgP and CP with genome-wide significance and highlights the role of innate and adaptive immunity in the etiology of periodontitis.