Validation of multivariable models for predicting tooth loss in periodontitis patients.

OBJECTIVES: A large number of multivariable models which associate independent variables with the outcome tooth loss exist. Directly or indirectly, these make predictions as to the relative risk of tooth loss. We aimed to validate six of these prediction models. METHODS: We applied each model, if needed after adaptions, in a cohort of 301 compliant periodontitis patients who had been under supportive periodontal treatment (SPT) in a university setting over 21.7 ± 5.6 years. The models employed a range of tooth-level and patient-level parameters. Model accuracy, that is, the ability to rightly predict tooth loss during SPT using baseline parameters, was investigated by the area under the receiver-operating-characteristics curve (AUC). RESULTS: Most models showed low accuracy (AUC ranged between 0.52 and 0.67). The classification model from Avila et al. (2009) Journal of Periodontology, 80, 476-491, expressing the risk of tooth loss in five grades, was most accurate (mean AUC: 0.67, 95%CI: 0.65/0.69). When applying this model, the risk of false-positively predicting tooth loss was high, except when the highest grade (i.e. a tooth being considered as having a hopeless prognosis) was used. In this case, the specificity was 84% and the sensitivity 46%. CONCLUSIONS: Predicting tooth loss in this specific cohort of periodontitis patients was only limitedly possible.

Effect of periodontitis history on implant success: a long-term evaluation during supportive periodontal therapy in a university setting.

OBJECTIVES: The aim of this retrospective study was to evaluate the long-term implant survival in patients with a history of chronic periodontitis, during supportive periodontal therapy (SPT), compared to periodontally healthy patients. MATERIALS AND METHODS: Twenty-nine periodontitis patients (test) with SPT for ≥9 years and implant-supported restorations (≥5 years follow-up) were recruited and pair-matched with 29 periodontally healthy patients (control). Subjects in both groups were examined following active periodontal therapy and/or implantation (T1) (test 69 implants, control 76 implants) and at end of SPT or supportive postimplant therapy (T2). Differences between the groups in implant survival (primary outcome), mean marginal bone loss (MBL) and pocket probing depths (PPDs) (secondary outcomes) were evaluated. RESULTS: Implant survival over 5 years was 97.1% in test compared to 97.4% in control group (p = 0.562). MBL was significantly different (test 18.7 ± 18.2%; control 12.5 ± 21.3%) (p < 0.05). PPDs increased at T2 in both groups (test: T1 3.4 ± 1.0 mm; T2 4.2 ± 1.6 mm; control: T1 1.0 ± 1.2 mm; T2 2.9 ± 0.8 mm; p < 0.05 between groups). Prognostic factors for implant loss appeared to be the presence of residual periodontal pockets of ≥4 mm (OR 1.90), bone height (OR 1.81) and age (OR 1.16) at T1. CONCLUSION: In terms of implant survival, no differences were observed between periodontitis and periodontally healthy patients. However, patients with history of periodontitis showed higher MBL and PPDs compared to periodontally healthy patients. CLINICAL RELEVANCE: The presence of a good periodontal maintenance program with preceding successful active periodontal treatment seems to be indispensable components of successful implant treatment in patients with history of chronic periodontitis.

Long-term tooth retention in chronic periodontitis - results after 18 years of a conservative periodontal treatment regimen in a university setting.

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.

Tooth loss in generalized aggressive periodontitis: Prognostic factors after 17 years of supportive periodontal treatment.

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.

Removal of simulated biofilm: an evaluation of the effect on root surfaces roughness after scaling.

BACKGROUND: 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. MATERIALS AND METHODS: Sonic (AIR), ultrasonic devices (TIG), and double-gracey curettes (GRA) were utilized by seven experienced (EO) and four less experienced operators (LO) for root surface instrumentation of standardized plastic teeth on manikins' heads in a randomized sequence. The proportion of residual simulated plaque (RSP area in %) was planimetrically assessed, and the average root surface roughness produced (Ra and ∆Ra in µm) was measured by a precision profilometer. RESULTS: The uninstrumented root surfaces showed a Ra of (median (Q25/Q75)) 1.00 µm (0.83/1.16). Following instrumentation, EO left significantly less RSP than LO regardless of the used instruments (20.00 % (10.00/34.00) vs. 26.00 % (12.00/44.00) p < 0.001), whereas the ∆Ra values (0.29 µm (-0.04/0.96) vs. 0.35 µm (-0.04/1.01), p = 0.237) failed to show significant differences. The surface roughness was higher with GRA followed by AIR then TIG regardless of operators' experience (p < 0.001). CONCLUSION: Within the limits of the present study, the sonic device was most efficient in plaque removal, while the ultrasonic device produced the least surface roughness. CLINICAL RELEVANCE: All three tested instruments seem effective in the mechanical root debridement during SPT, whereat the ultrasonic device show the smoothest root surface of all.

Cost-effectiveness of regular versus irregular supportive periodontal therapy or tooth removal.

AIM: For periodontitis patients, regular supportive periodontal therapy (SPT) decreases risks of tooth loss, with savings for tooth replacement possibly compensating SPT-costs. We aimed to assess the cost-effectiveness of regular versus irregular SPT, and to compare both strategies with immediate tooth removal. METHODS: A private payer perspective within German healthcare was adopted. A tooth-level Markov model was constructed. Replacement of 50% of removed teeth via implant-supported crowns was modelled in the base case. Cost-effectiveness was estimated as Euro/tooth retention year using Monte Carlo microsimulations. Scenario analyses were performed. RESULTS: Regular SPT was more effective (tooth retention 28.7 versus 26.1 years), but more costly (806 versus 731 Euro per tooth), with an incremental cost-effectiveness ratio (additional costs per tooth retention year) of 29 Euro/year. Regular SPT was less costly if costs for SPT per tooth and visit were <5.03 Euro, patients had high risk of tooth loss, or teeth were regularly replaced. Immediately removing and replacing teeth was usually most costly. CONCLUSIONS: Within the chosen healthcare setting and on the basis of current evidence, regular SPT retains teeth longer than irregular SPT, but does not necessarily reduce expenses. Decision-making should consider the subjective value placed on retaining teeth, the technical feasibility of replacement, and the impact of periodontal on general health.

Retention costs of periodontally compromised molars in a German population.

AIM: This study assessed the long-term costs per retention year for periodontally affected molars. METHODS: A cohort of 379 compliant subjects was retrospectively evaluated. Periodontal, restorative, endodontic, prosthetic and surgical treatment costs were estimated based on fee items of the private German health insurance. Costs/year were calculated and the impact of tooth- and subject-related factors on this cost-effectiveness ratio assessed using generalized linear-mixed modelling. RESULTS: 2306 molars received non-regenerative initial and supportive therapy and were followed until extraction or censoring (in mean (SD): 16.5 [6.8] years). Per year, 0.07 (SD: 0.12) deep scalings, 0.04 (0.11) open flap debridements, 0.01 (0.04) resective therapies and 2.49 (0.12) SPTs had been provided. Few teeth received non-periodontal treatments. Costs/year decreased significantly with each tooth a patient had at baseline (mean difference: -0.01, 95% CI: -0.02/-0.01 Euro/year), and increased with each mm of probing-pocket depth (0.04 [0.03/0.06] Euro/year), in upper (0.07 [0.11/0.31] Euro/year) or mobile molars (up to 0.33 [0.18/0.48] Euro/year), those with bone loss (up to 0.11 [0.04/0.17] Euro/year), endodontic treatment (0.24 [0.15/0.33] Euro/year), peri-apical lesions (0.24 [0.11/0.38]) and prosthetic treatment (0.54 [0.49/0.59] Euro/year). CONCLUSIONS: Annual costs for retaining periodontally affected molars were limited, and associated mainly with tooth-level factors.

Removal of simulated biofilm: a preclinical ergonomic comparison of instruments and operators.

BACKGROUND: Periodontal scaling might cause musculoskeletal disorders, and scaling instruments might not only have different effectiveness and efficiency but also differ in their ergonomic properties. The present study assessed ergonomic working patterns of experienced (EO) and less experienced operators (LO) when using hand and powered devices for periodontal scaling and root planning. METHODS: In an experimental study using periodontally affected manikins, sonic (AIR), ultrasonic (TIG) and hand instruments (GRA) were used by 11 operators (7 EO/4 LO) during simulated supportive periodontal therapy. Using an electronic motion monitoring system, we objectively assessed the working frequency and positioning of hand, neck and head. Operators' subjective evaluation of the instruments was recorded using a questionnaire. RESULTS: Hand instruments were used with the lowest frequency (2.57 ± 1.08 s(-1)) but greatest wrist deviation (59.57 ± 53.94°). EO used instruments more specifically than LO, and generally worked more ergonomically, with less inclination of head and neck in both the frontal and sagittal planes, especially when using hand instruments. All groups found hand instruments more tiring and difficult to use than powered instruments. CONCLUSION: Regardless of operators' experience, powered instruments were used more ergonomically and were subjectively preferred compared to hand instruments. CLINICAL RELEVANCE: The use of hand instruments has potential ergonomic disadvantages. However, with increasing experience, operators are able to recognise and mitigate possible risks.

Prognostic factors for the loss of molars--an 18-years retrospective cohort study.

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.

Subgingival instrumentation to remove simulated plaque in vitro: influence of operators' experience and type of instrument.

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.

Number of teeth predict depressive symptoms in a longitudinal study on patients with periodontal disease.

OBJECTIVE: Periodontal disease is associated with a wide range of psychosocial risk-factors. Disease-related tooth-loss has been associated with an increase in depressive symptoms in cross-sectional studies. However, while depression is a known risk-factor for the outcome of chronic diseases, it remains unclear if tooth loss can also predict depressive symptoms over the course of treatment. Aim of the current pilot study was to test, to what extend the number of teeth predict depressive symptoms several years later. METHODS: Tooth status of 310 patients with chronic and aggressive periodontitis was evaluated at the beginning of a specialized, university based outpatient treatment. We assessed depressive symptoms with the Patient Heath Questionnaire (PHQ) on average 13years later. Regression analyses were used to relate initial number of teeth to self-reported depression scores. RESULTS: Fewer teeth at the beginning of the treatment were related to higher scores of depressive symptoms, even when controlling for several covariates. CONCLUSIONS: Tooth loss is a potential risk-factor for the development of depression in periodontal disease. Further longitudinal studies that control for initial depressive symptoms are needed to identify disease mechanisms.

Effect of a Multidirectional Power Toothbrush and a Manual Toothbrush in Individuals Susceptible to Gingival Recession: A 12-Month Randomized Controlled Clinical Study.

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.

Efficacy versus health risks: An in vitro evaluation of power-driven scalers.

BACKGROUND: Power-driven instrumentation of root surfaces during supportive periodontal therapy is an alternative to hand instrumentation. The purpose of this pilot in vitro study was to investigate the efficacy of sub- and supragingival plaque removal with a sonic (AIR: Synea, W and H, Bürmoos, Austria) and two ultrasonic devices (TIG: Tigon+, W and H, Bürmoos, Austria; VEC: Vector, Dürr, Bietigheim-Bissingen, Germany) as well as the health-risk for dental professionals during treatment. MATERIALS AND METHODS: The power-driven devices were utilized to remove plaque from model teeth in dummy heads. The percentage of residual artificial plaque after 2 min of supra- or subgingival instrumentation was calculated by means of image-processing techniques at four sites (n = 576) of each tooth. The Health-Risk-Index (HRI: spatter/residual plaque quotient) with the different power-driven devices was assessed during treatment. RESULTS: The smallest amounts of residual plaque were found for the sonic device AIR (8.89% ± 10.92%) and the ultrasonic scaler TIG (8.72% ± 12.02%) (P = 0.707). Significantly more plaque was remained after the use of the ultrasonic scaler VEC (18.76% ± 18.07%) (P < 0.001). Irrespectively of the scaler, efficacy was similar sub- (10.7% ± 11.6%) and supragingivally (13.5% ± 17.2%) (P = 0.901). AIR/TIG demonstrated equal residual amounts of plaque sub- (P = 0.831) as well as supragingivally (P = 0.510). However, AIR/VEC and TIG/VEC were significantly in favor of AIR and TIG (P < 0.001). In contrast, the lowest HRI was found after using VEC (0.0043) and differed considerably for AIR (0.2812) and TIG (0.0287). CONCLUSION: Sonic devices are as effective as ultrasonic devices in the removal of biofilm but bear a higher risk to the dental professional's health concerning the formation of spatter.

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.

Periodontal probing versus radiographs for the diagnosis of furcation involvement.

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.