Abstract Consolidation of preclinical subgingival instrumentation skills during early clinical exposure is poorly quantified, especially after the new German dental licensing regulation (nGDLR). Within a shared digitised training programme (DTP), we compared in vitro performance after preclinical training and after the first periodontal patient course under distributed (oGDLR; 7th semester, S7) versus massed (nGDLR; 6th semester, S6) schedules. In a non-randomised, sequential two-cohort design (a consequence of a 2020 curriculum change), 102 students (oGDLR, distributed/longitudinal schedule, n = 45; nGDLR, massed/block schedule, n = 57) provided 136 evaluations after preclinical DTP (nGDLR S6, oGDLR S7) and/or after the first periodontal patient course (S8). Because oGDLR training (S7) overlapped with first clinical contacts whereas nGDLR training (S6) preceded intensive patient care by ~ 1.5 semesters, schedule density and clinical proximity co-vary and cannot be fully separated. Only 34 students (oGDLR n = 22; nGDLR n = 12) were evaluated at both time points, so most comparisons are cross-sectional. Each student instrumented six teeth with Gracey curettes (GRA) and a sonic scaler (AIR) on periodontitis manikins. Effectiveness of simulated plaque removal (ESP), treatment time, calculus removal and an 8-item Likert self-assessment were analysed by non-parametric tests and multivariable regression with cluster-robust SE. oGDLR was associated with higher ESP (β=+5.16%, p = 0.001) and twofold higher calculus removal (adjusted OR 2.00, p < 0.001); treatment time was comparable. From post-DTP to S8 both cohorts became faster by ~ 60s/tooth (p < 0.001) while ESP declined (β=−4.26%, p = 0.002) — a speed–accuracy trade-off; the schedule×time interaction was non-significant. In the paired subgroup, the trade-off was confirmed in oGDLR (n = 22; ESP − 7.2%, p < 0.001) but power-limited in nGDLR (n = 12). Excluding magnifying-loupe users (concentrated in nGDLR) widened rather than narrowed the oGDLR ESP advantage (β=+6.02%, p < 0.001). nGDLR rated AIR more favourably (learnability OR 0.40; effectiveness OR 0.48). Pass rates (≥ 55% ESP) exceeded 86%. In this non-randomised cohort, the distributed schedule was associated with higher absolute performance, but the decline occurred similarly under both schedules. Because schedule density could not be separated from proximity to clinical exposure, and because the data are largely cross-sectional and derive from a manikin-based in vitro model, these associations should not be read as causal. The transition to first patient care is vulnerable: cleaning quality may erode as students prioritise speed. Distributed preclinical practice was associated with a higher absolute baseline, but the decline across the transition was similar in both schedules; structured reinforcement during the early clinical phase remains necessary to consolidate competence.

OBJECTIVE:This two-centre, double-blind, randomized, parallel-group study compared the efficacy and safety of a novel powered full-mouth cleaning device system (FMCD) with habitual toothbrushing (CG) in patients with generalized gingivitis over 6 weeks. METHODS:Participants between 18 and 65 years with generalized plaque-induced gingivitis were randomly assigned to FMCD (n = 62) or CG (n = 61). At baseline and after 6 weeks, participants were clinically examined. The primary outcome parameter was the change of bleeding on marginal probing (BOMP). As secondary parameters, the extended Turesky modified Quigley Hein plaque index (PI), gingival abrasions (GA), pocket probing depth (PPD), clinical attachment level (CAL), gingival recessions (GR), oral health impact profile and motivational factors for toothbrushing were evaluated. RESULTS:BOMP did not differ significantly between FMCD and CG neither at baseline (FMCD: 66.90% ± 19.28%/CG: 64.13% ± 18.50%; p = 0.415) nor did the change after 6 weeks (FMCD: 0.17% ± 15.93%; -3.47% ± 14.01%; p = 0.181). PI did not differ significantly between groups at baseline (FMCD: 2.95 ± 0.45/CG: 2.96 ± 0.41; p = 0.948), but the change after 6 weeks differed statistically significantly between the groups (FMCD: 0.16 ± 0.41/CG: -0.06 ± 0.39; p = 0.003). GA and GR showed clinically minor though statistically significant differences between the groups that were not considered clinically relevant. No other secondary outcomes differed between groups. There were no serious adverse events. CONCLUSION:The FMCD seems to be equally effective compared to a habitually used toothbrush regarding parameters of gingivitis but slightly less effective with regard to parameters of plaque.

Background: To compare acceptance and preference of topical lidocaine gel anesthesia with articaine injection anesthesia in patients with moderate periodontitis undergoing scaling and root debridement. Methods: Ninety-one patients completed this randomized multicenter split-mouth controlled study and underwent two separate periodontal treatment sessions on different days, one with a topical intrapocket lidocaine gel application and the other with an articaine injection anesthesia in a different order depending on randomization. Parameters measured were the patients' preference for topical lidocaine gel anesthesia or injection anesthesia with articaine (primary efficacy criterion), their maximum and average pain, and their intensity of numbness as well as experience of side effects; the probing depth; and the dentists' preference and their evaluations of handling/application, onset and duration of anesthetic effect, and patient compliance. Results: After having experienced both alternatives, 58.3% of the patients preferred the topical lidocaine gel instillation into the periodontal pockets. The safety profile of the lidocaine gel differed positively from the safety profile of articaine injection in type and frequency of adverse drug reactions. The dentists' acceptance and preference regarding either anesthetic method studied were balanced. Conclusions: Instillation of lidocaine gel into the periodontal pocket is a preferred alternative to injection anesthesia for most of the patients and an equivalent alternative for dentists in nonsurgical periodontal therapy.

Abstract Background The aim of the randomized controlled clinical trial study was to evaluate the effectiveness in reducing pathologically increased pocket probing depths (PPD > 3 mm) using the Guided Biofilm Therapy (GBT) protocol (adapted to the clinical conditions in non-surgical periodontal therapy (NSPT): staining, air-polishing, ultrasonic scaler, air-polishing) compared to conventional instrumentation (staining, hand curettes/sonic scaler, polishing with rotary instruments) both by less experienced practitioners (dental students). Methods All patients were treated according to a split-mouth design under supervision as diseased teeth of quadrants I/III and II/IV randomly assigned to GBT or conventional treatment. In addition to the treatment time, periodontal parameters such as PPD and bleeding on probing (BOP) before NSPT (T0) and after NSPT (T1: 5 ± 2 months after T0) were documented by two calibrated and blinded examiners (Ethics vote/ Trial-register: Kiel-D509-18/ DRKS00026041). Results Data of 60 patients were analyzed (stage III/IV: n = 36/ n = 24; grade A/ B/ C: n = 1/ n = 31/ n = 28). At T1, a PPD reduction of all diseased tooth surfaces was observed in 57.0% of the GBT group and 58.7% of the control group (p = 0.067). The target endpoint (PPD ≤ 4 mm without BOP) was achieved in 11.5% for GBT (conventional treatment: 11.2%; p = 0.714). With the exception for number of sites with BOP, which was at T1 15.9% in the GBT group and 14.3% in the control group (p < 0.05) no significant differences between the outcomes of the study were found. At 30.3(28.3) min, the treatment time was significantly shorter in GBT than in the control group at 34.6(24.5) min (p < 0.001). Conclusions With both protocols (GBT/ conventional instrumentation) comparably good clinical treatment results can be achieve in NSPT in stage III-IV periodontitis patients. Trial registration The study was registered before the start of the study and can be found under the number DRKS00026041 in the German Clinical Trials Register. The registration date was 19/08/2021.

OBJECTIVE:Although the therapeutic effects of nonsurgical periodontal therapy (NSPT) are well established, the clinical benefits of the additional use of periodontal endoscopy (PE) remain controversial. Therefore, this randomized controlled split-mouth pilot study evaluated the effect of NSPT using PE versus NSPT without nPE on bleeding on probing (BOP) in sites with probing depth (PD)≥4 mm (primary outcome), PD, clinical attachment level (CAL), number of hard deposits (HDs), and treatment time per tooth (TrT).METHODS:Two calibrated operators performed NSPT in twenty periodontitis patients, randomized into two quadrants for PE or nPE treatment. BOP, PD, and CAL were recorded at the first visit for NSPT (T0) and during reevaluation (T1: mean (SD) 119.7 (24.6) days after T0). The average TrT and the number of sites with HDs were documented at T0.RESULTS:For BOP, no significant differences were found at the patient's level (10/10 (male/female); aged 54.3 (10.9) years) neither within or between the groups. At tooth surface level, a lower number of surfaces with BOP (p=0.026) was observed in nPE. CAL and PD improved significantly during NSPT in both groups (p ≤ 0.001), with higher PD reduction (p < 0.001) and CAL gain (p < 0.001) in nPE. There are significantly longer TrT (p < 0.001) and more surfaces with subgingival HDs evident in PE at T0 (p=0.001).CONCLUSION:Whereas subgingival HDs can be visually detected with PE during NSPT, no additional clinical benefits regarding BOP, PD, or CAL were notable compared to conventional systematic periodontal instrumentation. Additionally, PE-assisted NSPT required a longer treatment time.

OBJECTIVES:We aimed to assess how the 2018 and 1999 classifications of periodontal diseases reflect (a) patients' characteristics, (b) disease severity/extent/progression and (c) tooth loss (TL) during observation period.METHODS:A total of 251 patients were followed over 21.8 ± 6.2 years. For the 1999 classification, using clinical attachment level (CAL), patients were classified as localized/generalized, mild/moderate/severe and aggressive/chronic periodontitis. For the 2018 classification, patients were staged according to their CAL or bone loss (BL) and the number of lost teeth (stages I-IV). Further factors like probing pocket depths (PPD) or furcation involvement modified the stage. The extent was sub-classified as generalized/localized. Patients were graded according to the BL/age index, smoking and/or diabetes.RESULTS:According to the 1999 classification, most patients suffered from generalized severe chronic periodontitis (203/251) or generalized aggressive periodontitis (45/251). Patients with aggressive periodontitis were younger and less often female or smokers. They showed similar TL (0.25 ± 0.22 teeth/patient*year) as generalized severe chronic periodontitis patients (0.23 ± 0.25 teeth/patient*year). According to the 2018 classification, most patients were classified as generalized III-C (140/251), III-B (31/251) or IV-C (64/251). Patients' age, smoking status, CAL, PPD and BL were well reflected. TL differed between IV-C (0.36 ± 0.47), generalized III-C (0.21 ± 0.24) and localized forms (0.10-0.15).CONCLUSIONS:Patients' characteristics, disease severity/extent/progression and TL were well reflected by the 2018 classification.

Objectives: For extracted teeth in periodontitis patients, adhesively attaching their crown to the adjacent teeth temporarily closes the otherwise resulting gap, allowing to postpone more comprehensive prosthetic treatment to a more appropriate time if required. This study assessed the survival and maintenance efforts of adhesively attached extracted tooth crowns ('immediate pontics'; IPs). Methods: Patients receiving active and supportive periodontal treatment involving IPs in a university setting were retrospectively assessed. Survival and repairs of IPs were recorded. Multilevel Cox and linear regression analyses were performed to assess factors associated with survival and maintenance efforts. Results: Twenty-seven patients (male/female: 12/15) with 34 IPs (maxilla/mandible: 13/21) were followed over mean +/- SD 8.0 +/- 5.0 [range: 2.0-19.3] years. At baseline 85.2% suffered from periodontitis stage II or III and 59.3% showed rapid progression (grade C). The mean (95% CI) survival time of splinting was 5.3 +/- 3.8 [range: 0.1-18.0] years. Three IPs had been removed without any significant association with patient- or tooth-level factors. 35.3% of the IPs (n = 12) required a repair, with a mean of 0.5 +/- 0.9 [0-3] repairs per IP (annual: 0.1 +/- 0.2 [0-0.5]). The risk of repairs significantly increased with patients' age (p = 0.018). Conclusion: IPs showed moderate survival. However, to maintain IPs, frequent repairs were needed. Clinical significance: Immediately and adhesively attached crowns of extracted teeth in periodontitis patients seems like a valid, albeit temporary strategy which may allow to postpone more comprehensive prosthetic treatment if required, for example during active periodontal therapy. However, to maintain immediate pontics, frequent repairs were needed.

AIM:The longitudinal study assessed the risk of tooth loss under a non-regenerative treatment regimen and aimed to identify prognostic factors for tooth loss.METHODS:Three hundred and fifteen patients (8009 teeth) were examined before (T0) and after active periodontal therapy (APT, T1) as well as after (mean ± SD) 18 ± 6 years of supportive periodontal therapy (SPT, T2). Descriptive statistics and a Cox proportional hazards shared-frailty model were applied.RESULTS:Overall, 351 and 816 teeth were lost during APT and SPT, respectively, with 0.15 ± 0.17 teeth being lost per patient and year. Seventy-two percentage patients lost 0-3, 24% 4-9 and 4% ≥10 teeth. The proportion of teeth with probing-pocket depths (PPD) >6 mm was 17.2% (T0), 1.6% (T1) and remained stable at 1.7% up to T2. Tooth loss during SPT was significantly increased in older patients [HR (95% CI): 1.04 (1.01-1.07) per year] and smokers [2.62 (1.34-5.14)], with each mm of PPD [1.35 (1.17-1.56)], in multirooted compared with single-rooted teeth [1.86 (1.36-2.56)] and teeth with bone loss [BL; HR up to 23.6 (12.1-45.6) for BL > 70%].CONCLUSION:The risk of tooth loss was generally low under the provided non-regenerative treatment regimen; a minority of patients were responsible for the majority of teeth lost during SPT.

AIM This retrospective longitudinal study assessed the risk of and prognostic factors for tooth loss in patients with generalized aggressive periodontitis (GAgP) after periodontal treatment in a university setting. METHODS Fifty-seven patients (1,505 teeth) were examined before (T0) and after active periodontal therapy (APT, T1) as well as after 17.4 ± 4.8 [range: 9-28] years of supportive periodontal therapy (SPT, T2). Descriptive statistics and a Cox-proportional-hazards shared-frailty model were applied. RESULTS Overall, 98 and 134 teeth were lost during APT and SPT, respectively, with 0.14 ± 0.18 teeth being lost per patient and year. During SPT, three patients (5%) lost ≥10 teeth, 14 (25%) lost 4-9 teeth, 40 lost 0-3 (70%) teeth, respectively. One-third (n = 19) of all patients lost no teeth. Mean PPD of the teeth surviving SPT was stable from T1 (3.5 ± 1.1 mm) to T2 (3.4 ± 1.1 mm). Nearly, 84% of all survived teeth showed stable or improved bone level at T2. Risk of tooth loss was significantly increased in active smokers (HR[95% CI]: 4.94[1.91/12.75]), the upper dental arch (1.94[1,16/3.25]), with each mm of residual PPD (1.41[1.29/1.53]), teeth with furcation involvement (FI) (HR 4.00-4.44 for different degrees) and mobility (5.39 [2.06/14.1] for degree III). CONCLUSION Within the provided conservative treatment regimen, GAgP patients lost only few teeth.

Despite the development of less invasive devices, a debate exists about the benefits and risks of hand versus powered root surface instrumentation used in supportive periodontal therapy (SPT). The aim of the in vitro study was to differentially compare plaque removal efficacy and root surface roughening of newly developed sonic, ultrasonic scaler, and curettes in the hands of experienced versus less experienced operators.

BACKGROUND Clinical studies have explored the relationship between toothbrushing and development of gingival recession (GR), but relevant GR data for the multidirectional power toothbrush (PT) are lacking. The aim of this study is to evaluate the effect of brushing with either a multidirectional PT or American Dental Association reference manual toothbrush (MT) on mid-buccal preexisting GR (PreGR) during 12 months. METHODS This was a 12-month prospective, single-masked, parallel-group, randomized, controlled clinical study. Healthy participants without periodontitis with at least two teeth showing PreGR ≥2 mm were randomized to a group brushing with either an MT or PT. The primary outcome parameter was change at sites with PreGR ≥2 mm. All clinically based GR measurements were performed by one calibrated examiner at baseline, 6, and 12 months. Secondary outcomes were changes of GR at all mid-buccal sites (with or without PreGR), changes in percentage of GR sites demonstrating a change of ≥1 mm, and changes in probing depths. RESULTS A total of 107 participants completed the study (PT: 55, MT: 52). During the 12-month study period the mean recession at sites with PreGR ≥2 mm decreased significantly from 2.2 to 2.1 mm in both groups (P <0.05). The extent of GR parameters did not differ between MT and PT groups at any time point. GR evaluated clinically and on stone casts was well correlated. CONCLUSION Neither the PT nor MT led to an increase in PreGR during 12 months of daily use.

AIM:The aim of this study was to identify long-term prognostic factors for the loss of molars with different degrees of furcation involvement (FI) during supportive periodontal therapy (SPT).METHODS:Three hundred and seventy-nine compliant subjects with 2373 molars at baseline were retrospectively assessed. After nonsurgical (n = 76) or surgical (n = 303) non-regenerative active periodontal therapy (APT: T0-T1), patients remained under SPT (T1-T2) for 18.3 ± 5.5 (9-30.8) years. Association between tooth- and subject-related factors with tooth loss was assessed using multilevel Cox regression-analysis.RESULTS:During APT 159 and during SPT 438 molars were extracted in 256 subjects, respectively, yielding an overall survival of 74.8% (T2). Survival probabilities after 15-years of SPT were 92.4% for molars with FI-0 compared to FI-1 = 85.6%, FI-2 = 74.9% and FI-3 = 62.3%. The risk of molar loss was significantly increased for teeth with FI-3 (hazard ratio: 2.39 [95% confidence interval: 1.54-3.70]), bone loss >50% (2.16 [1.36-3.42]), mobile teeth (2.07 [1.51-2.84]), maxillary molars (1.44 [1.12-1.85]) and endodontically treated teeth (1.89 [1.58-2.26]). For each mm of mean residual pocket probing depth, the hazard of tooth loss increased 1.89-fold (1.58-2.26). On a subject level, for each year of age, HR was 1.03 (1.01-1.05).CONCLUSIONS:Furcation involvement, bone loss, tooth mobility, mean pocket depth and age strongly predicted tooth loss during SPT. Long-term retention of periodontally compromised molars was possible via conservative non-regenerative active and supportive therapy.

BACKGROUND:There is uncertainty regarding the benefits and risks of hand versus powered root surface instrumentation. Moreover, the influence of operators' experience on treatment results is unclear. We compared newly developed sonic, ultrasonic and hand instruments, hypothesizing that powered devices allow to remove more simulated plaque in less time than hand instruments, with significant influence of operators' experience. METHODS:Sonic scaler (AIR), ultrasonic scaler (TIG) device and double Gracey curettes (GRA) were utilized by seven experienced operators (EOs) and four less experienced operators (LOs) in periodontitis manikin heads. The time required for treatment, the proportion of residual-simulated plaque and the weight loss caused by scaling as a proxy for root surface destruction were measured. RESULTS:Using different instruments led to significantly different proportions of removed simulated plaque regardless of operators' experience (AIR, 80.2 ± 21.3 %, TIG, 69.9 ± 22.5 %, GRA, 73.1 ± 20.0 %) (p < 0.001). Treatment times did not significantly differ between EO and LO (p > 0.05). Weight loss was increased when using hand instead of powered instruments (p < 0.001), with significantly higher weight loss induced by LO than EO (p = 0.004). CONCLUSION:Within the present study, EO did not remove more simulated plaque in less time but induced less root surface destruction. Using a sonic device was most beneficial for plaque removal. CLINICAL RELEVANCE:Successful root surface debridement requires both time and training regardless of the used instrument. Hand instruments might cause more damage to root surfaces, especially in the hands of less experienced operators.

BACKGROUND:Decisions in periodontal therapy for multirooted teeth are essentially based on accurate diagnosis of the furcation involvement (FI). Furcation probing (FP) is still the basic diagnostic measure, although the assessment may be difficult. The aim of this study is to evaluate the validity of FP and radiographic assessment of FI compared with visual assessment during open flap surgery (OFS). METHODS:In this retrospective clinical cohort study, 215 participants with periodontal disease and at least one molar treated with OFS were enrolled, and a total of 834 molars were assigned for FI by FP and in radiographs analyzed by an experienced (EE) and less experienced examiner (LE). For the investigation, 143 panoramic radiographs (OPGs) and 77 intra-oral radiographs (I-Os) were evaluated. RESULTS:The Class of FI by FP was confirmed in 56%, whereas 15% were overestimated and 29% underestimated. FI Class 0 and I had been detected with high probability (74% and 54%, respectively). Of all FI Class III, 57% were detected correctly by radiographs and 32% by FP. FP and OFS revealed a weighted κ-coefficient (κw) = 0.588; radiographs and OFS had κw = 0.542 (OPG κw = 0.555 and I-O κw = 0.521). The interrater reliability for radiographs was dependent on the experience of the examiner (EE κw = 0.618; LE κw = 0.426). CONCLUSIONS:Experience in analyzing conventional radiographs increases the potential of correct diagnosis of advanced FI. The reliability of FP compared with radiographic assessment depends on the anatomy and location of the tooth. Both diagnostic tools should be used in cases of suspected FI.

BACKGROUND The aim of this study is to evaluate the efficiency of a recently developed smart digital toothbrush monitoring and training system (DTS) in terms of correct brushing motion and grip axis orientation in an at-home environment. METHODS Twenty-one participants (11 test individuals [DTSG] and 10 control individuals [COG]) received instructions on the modified Bass technique (MBT) after their toothbrushing performance was monitored and they received professional tooth cleaning (T0). After 36 hours (T1), without mechanical oral hygiene measures, plaque and gingival indices were recorded, and the brushing technique was reviewed. After randomization, participants individually performed oral hygiene for 6 weeks (T2) with the provided oral hygiene kits. The DTSG group additionally used DTS. During the following 8 weeks (T3), participants used their original brushing devices without any additional interference. Investigators at each visit were masked regarding group identity. Data were statistically evaluated using Mann-Whitney U, Friedman, Wilcoxon, and paired tests and Pearson correlation. RESULTS At T0, 27.27% of DTSG participants used the MBT correctly (COG, 50%), increasing to 54.55% (COG, 60%) after professional instruction (T1) and further to 90.91% at T2 (COG, 60%) (P <0.001). Plaque scores were reduced in DTSG (P <0.05). At T3, 80% of the DTSG (COG, 40%) totally adopted the MBT (P <0.05). The plaque scores on buccal surfaces of the DTSG showed an additional slight improvement between T2 and T3, in contrast to a decline on oral surfaces (P <0.001). At T2 and T3, the DTSG brushed >120 seconds (COG, 90% and 50%) (P <0.05). CONCLUSION Apparently, the tested DTS effectively improves the brushing technique and leads to a prolonged learning effect, including improved oral hygiene.

OBJECTIVES Long-term outcomes of conservative periodontal and prosthetic treatment of patients with moderate to severe periodontitis were to be evaluated. Groups of younger (YG) and middle-aged patients (MG) were to be compared regarding survival of fixed and removable dental prostheses (FDP, RDP) inserted after active periodontal therapy (APT). In addition, functional-occlusal status over more than 10 years of supportive periodontal therapy (SPT) was analysed. METHODS The present multi-case-series retrospectively analysed data of 68 patients (34 YG and 34 MG) who had received APT and regular SPT ≥10 years. Tooth loss, occlusal status and survival and complications of prosthetics were evaluated descriptively and comparatively (t-test). RESULTS There was no statistical difference between YG and MG concerning tooth loss/year (p > 0.05). Functional-occlusal status was retained during SPT in 75% and 69% of YG and MG. Restorations inserted after APT showed high survival for both age groups (100%). Mean survival time until the last SPT visit was 15.2 and 11.6 years for FDP and RDP in YG, and 12.5 and 13.1 years in MG. CONCLUSIONS Prosthetic restorations in both younger and middle-aged patients with severe periodontitis showed high survival, if pre-prosthetic APT and regular SPT had been performed.