Prognostic model for tooth survival in patients treated for periodontitis

Systematic Review of Prognosis Models in Predicting Tooth Loss in Periodontitis

This study reviews and appraises the methodological and reporting quality of prediction models for tooth loss in periodontitis patients, including the use of regression and machine learning models. Studies involving prediction modeling for tooth loss in periodontitis patients were screened. A search was performed in MEDLINE via PubMed, Embase, and CENTRAL up to 12 February 2022, with citation chasing. Studies exploring model development or external validation studies for models assessing tooth loss in periodontitis patients for clinical use at any time point, with all prediction horizons in English, were considered. Studies were excluded if models were not developed for use in periodontitis patients, were not developed or validated on any data set, predicted outcomes other than tooth loss, or were prognostic factor studies. The CHARMS checklist was used for data extraction, TRIPOD to assess reporting quality, and PROBAST to assess the risk of bias. In total, 4,661 records were screened, and 45 studies were included. Only 26 studies reported any kind of performance measure. The median C-statistic reported was 0.671 (range, 0.57-0.97). All studies were at a high risk of bias due to inappropriate handling of missing data (96%), inappropriate evaluation of model performance (92%), and lack of accounting for model overfitting in evaluating model performance (68%). Many models predicting tooth loss in periodontitis are available, but studies evaluating these models are at a high risk of bias. Model performance measures are likely to be overly optimistic and might not be replicated in clinical use. While this review is unable to recommend any model for clinical practice, it has collated the existing models and their model performance at external validation and their associated sample sizes, which would be helpful to identify promising models for future external validation studies.

Influence of mobility on the long-term risk of tooth extraction/loss in periodontitis patients. A systematic review and meta-analysis

The aim of this systematic review (SR) was to assess whether tooth mobility (TM) increases the risk of tooth extraction/loss. The protocol was registered in PROSPERO database (CRD42023485425). The focused PECO questions were as follows: (1) "In patients with periodontitis, undergoing periodontal treatment, are teeth affected by mobility at higher risk of being extracted/lost compared to non-mobile teeth, with a minimum follow-up of 10 years?" and (2) "In these patients, does varying degrees of tooth mobility increase the risk of tooth extraction/loss, with a minimum follow-up of 10 years?". Results were reported according to PRISMA statement. Electronic and manual searches were conducted to identify longitudinal studies. The different assessments of tooth mobility were pooled into three groups: TM0: Undetectable tooth mobility, TM1: Horizontal/Mesio-distal mobility ≤1 mm, TM2: Horizontal/Mesio-distal mobility >1 mm or vertical tooth mobility. Tooth loss was the primary outcome. Various meta-analyses were conducted, including subgroup analyses considering different follow-up lengths and the timing of TM assessment, along with sensitivity analyses. A trial sequential analysis was also performed. Eleven studies were included (1883 patients). The mean follow-up range was 10-25 years. The weighted total of included teeth, based on the sample size, was 18 918, with a total of 1604 (8.47%) extracted/lost teeth. The overall rate of tooth extraction/loss increased with increasing mobility: TM0 was associated with a 5.85% rate (866/14822), TM1 with the 11.8% (384/3255), TM2 with the 40.3% (339/841). Mobile teeth (TM1/TM2) were at an increased risk for tooth extraction/loss, compared to TM0 (HR: 2.85; [95% CI 1.88-4.32]; p < .00001). TM1 had a higher risk than TM0 (HR: 1.96; [95% CI 1.09-3.53]; p < .00001). TM2 had a higher risk than TM1 (HR: 2.85; [95% CI 2.19-3.70]; p < .00001) and TM0 (HR: 7.12; [95% CI 3.27-15.51]; p < .00001). The results of the tests for subgroup differences were not significant. Sensitivity meta-analyses yielded consistent results with other meta-analyses. Within the limits of the quality of the studies included in the meta-analyses, mobile teeth were at higher risk of being extracted/lost in the long-term and higher degrees of TM significantly influenced clinicians' decision to extract a tooth. However, most teeth can be retained in the long-term and thus TM should not be considered a reason for extraction or a risk factor for tooth loss, regardless of the degree of TM.

Vital root resection with radicular retrograde partial pulpotomy in furcation-involved maxillary molars in patients with periodontitis: Technique description and case series considering clinical and economic aspects

AIM

Conventional root resection in periodontally compromised furcation-involved maxillary molars requires preceding endodontic treatment and is therefore associated with loss of tooth vitality, higher invasiveness, treatment time and costs, and the risk of endodontic complications. Vital root resection (VRR) could overcome these disadvantages while establishing stable periodontal and endodontic conditions. This case series aimed to introduce the concept of one-stage VRR with radicular retrograde partial pulpotomy (VRRretro).

SUMMARY

Seven vital maxillary molars with residual probing pocket depths (PPD) ≥ 6 mm and furcation ≥ class 2 of five patients with stage III/IV periodontitis were treated with VRRretro using mineral trioxide aggregate. Teeth with residual through-and-through furcations were additionally tunnelled. Follow-up up to 2.5 years postoperatively during supportive periodontal care included full periodontal status, percussion and thermal sensitivity testing. Periapical radiographs were obtained to rule out possible periradicular radiolucencies. All seven treated molars were in-situ at an average of 26.84 ± 5.37 months postoperatively and were clinically and radiographically inconspicuous independent of tooth position, the resected root, the need for tunnelling and the restorative status. The mean PPD on the seven treated molars was 4.02 ± 0.85 mm (6-10 mm) preoperatively and 2.62 ± 0.42 mm (3-4 mm) at the last follow-up. Clinical attachment level and bleeding on probing could also be decreased. The teeth showed no mobility over time and furcations class 2 were reduced to class 1 while the tunnelled furcations were accessible with interdental brushes. All molars reacted negatively to percussion and positively to thermal sensitivity testing.

KEY LEARNING POINTS

In carefully selected cases considering patient- and tooth-related factors, VRRretro could be a promising treatment option to establish stable periodontal and endodontic conditions in furcation-involved maxillary molars while preserving tooth vitality.

Modelling time-varying risk factors of tooth loss: Results from joint model compared with extended Cox regression model

AIM

To illustrate the use of joint models (JMs) for longitudinal and survival data in estimating risk factors of tooth loss as a function of time-varying endogenous periodontal biomarkers (probing pocket depth [PPD], alveolar bone loss [ABL] and mobility [MOB]).

MATERIALS AND METHODS

We used data from the Veterans Affairs Dental Longitudinal Study, a longitudinal cohort study of over 30 years of follow-up. We compared the results from the JM with those from the extended Cox regression model which assumes that the time-varying covariates are exogenous.

RESULTS

Our results showed that PPD is an important risk factor of tooth loss, but each model produced different estimates of the hazard. In the tooth-level analysis, based on the JM, the hazard of tooth loss increased by 4.57 (95% confidence interval [CI]: 2.13-8.50) times for a 1-mm increase in maximum PPD, whereas based on the extended Cox model, the hazard of tooth loss increased by 1.60 (95% CI: 1.37-1.87) times.

CONCLUSIONS

JMs can incorporate time-varying periodontal biomarkers to estimate the hazard of tooth loss. As JMs are not commonly used in oral health research, we provide a comprehensive set of R codes and an example dataset to implement the method.

Probing pocket depth reduction after non-surgical periodontal therapy: Tooth-related factors

BACKGROUND

To investigate tooth-related factors that influence the reduction of probing pocket depths (PPD) after non-surgical periodontal therapy (NST).

METHODS

Seven hundred forty-six patients with a total of 16,825 teeth were included and retrospectively analyzed. PPD reduction after NST was correlated with the tooth-related factors; tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration; using logistic multilevel regression for statistical analysis.

RESULTS

NST was able to reduce probing depth overall stratified probing depths (1.20 ± 1.51 mm, p ≤ 0.001). The reduction was significantly higher at teeth with higher probing depths at baseline. At pockets with PPD ≥ 6 mm, PPD remains high after NST. Tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration are significantly and independently associated with the rate of pocket closure.

CONCLUSIONS

The tooth-related factors: tooth type, number of roots, furcation involvement, vitality, mobility, and type of restoration had a significant and clinically relevant influence on phase I and II therapy. Considering these factors in advance may enhance the prediction of sites not responding adequately and the potential need for additional treatment, such as re-instrumentation or periodontal surgery, to ultimately achieve the therapy end points.

Clinical periodontal diagnosis

Periodontal diseases include pathological conditions elicited by the presence of bacterial biofilms leading to a host response. In the diagnostic process, clinical signs such as bleeding on probing, development of periodontal pockets and gingival recessions, furcation involvement and presence of radiographic bone loss should be assessed prior to periodontal therapy, following active therapy, and during long-term supportive care. In addition, patient-reported outcomes such as increased tooth mobility, migration, and tilting should also be considered. More important to the patient, however, is the fact that assessment of signs of periodontal diseases must be followed by an appropriate treatment plan. Furthermore, it should be realized that clinical and radiographic periodontal diagnosis is based on signs which may not reflect the presence of active disease but rather represent the sequelae of a previous bacterial challenge. Hence, the aim of the present review is to provide a summary of clinical and radiographic diagnostic criteria required to classify patients with periodontal health or disease.

Effect of splinting material type and location on resistance against deflection force of splinted periodontally compromised teeth with hypermobility

This study aimed to evaluate the effect of splinting material type and material location on the force resistance of splinted periodontally compromised teeth with hypermobility. Extracted teeth including the target tooth (maxillary second premolar) and its adjacent teeth were placed into the alveolar sockets of a dental arch model via artificial periodontal ligaments made of elastic impression material. Three different experimental models with varied target tooth mobility including Periotest® values (PTVs) of 20, 30, and 40 were fabricated (named models #20, #30, and #40, respectively). For each experimental model, the force resistance of tooth splinting was tested using the following four materials: everStick PERIO (glass fiber reinforcement: GFR), FORESTAFLEX (braided stainless steel: BSS), Ortho-FlexTech (stainless steel chain: SSC), and Super-Bond (MMA-based resin cement: MRC). The evaluated measures were the PTV after tooth splinting and the required load to cause tooth displacements of 0.05 mm and 0.10 mm in the vertical and lateral directions, respectively. The splinting material type and material location as well as the original PTV of target the tooth significantly affected all the evaluated measures (p < 0.001). MRC revealed the significantly highest force resistance of tooth splinting regardless of material location in each experimental model and was followed by GFR. The PTVs of splinted teeth were comparable to those of adjacent anchor teeth in models #20 and #30 when using GFR, while that was comparable in model #40 when using MRC. Meanwhile, the load causing certain tooth displacement showed a similar tendency to previous-reported data with healthy teeth in model #20 when using GFR, while that showed a similar tendency in models #30 and #40 when using MRC. Overall results concluded that splinting material type and location play a role in the resistance against the deflection force of splinted periodontally compromised hypermobile tooth. It was noted that MRC provided the highest resistance against the deflection force of splinted teeth regardless of material location whereas GFR maintained the physiologically considered tooth mobility.

Comparing the Long-Term Success Rates of Tooth Preservation and Dental Implants: A Critical Review

Implant therapy is considered a predictable, safe, and reliable rehabilitation method for edentulous patients in most clinical scenarios. Thus, there is a growing trend in the indications for implants, which seems attributable not only to their clinical success but also to arguments such as a more “simplified approach” based on convenience or the belief that dental implants are as good as natural teeth. Therefore, the objective of this critical literature review of observational studies was to discuss the evidence concerning the long-term survival rates and treatment outcomes, comparing endodontically or periodontally treated teeth with dental implants. Altogether, the evidence suggests that the decision between keeping a tooth or replacing it with an implant should carefully consider the condition of the tooth (e.g., amount of remaining tooth and degree of attachment loss and mobility), systemic disorders, and patient preference. Although observational studies revealed high success rates and long-term survival of dental implants, failures and complications are common. For this reason, attempts should be made to first save maintainable teeth over the long-term, instead of immediately replacing teeth with dental implants.

Biomechanical properties of periodontal tissues in non-periodontitis and periodontitis patients assessed with an intraoral computerized electronic measurement device

OBJECTIVE

To identify tooth mobility (TM) by time-dependent tooth displacement using an electronic intra-oral loading device (ILD) in periodontally healthy and periodontally compromised patients.

MATERIALS AND METHODS

Twenty-eight untreated periodontitis and 20 periodontally healthy patients [25 female and 26 male; ages: 20-81 years], contributing with 68 teeth (periodontitis: n_teeth = 28; non-periodontitis: n_teeth = 40), participated in the study. TM was measured in vivo by displacing central or lateral incisors to a maximum of 0.2 mm orally over durations of 0.5 s, 1 s, and 10 s with the ILD. The maximum force (Fmax) was extracted from the measured force/deflection curves for every single measurement.

RESULTS

Differences in TM-ILD values were found for periodontitis as compared to non-periodontitis patients derived from the same loading durations (differences of 3.9 (0.5 s), 3.1 (1 s), 2.8 (10 s), (95% CI for 0.5 s (1.2-6.7), p = 0.024; 1 s (1.4-6.0), p = 0.067; 10 s (0.2-5.3), p = 0.001), rejecting the null hypothesis of no difference (T-test) for durations of 0.5 and 10 s. There was a significant correlation of TM-ILD (Fmax) with BOP at 0.5 s (- 0.52) and with attachment loss at all time durations (- 0.47 at 0.5 s; - 0.57 at 1 s; - 0.47 at 10 s).

CONCLUSIONS

This clinical investigation could demonstrate that time-dependent tooth displacements using a new computerized electronic device were associated with attachment loss and bleeding on probing.

CLINICAL RELEVANCE

ILD can improve the monitoring of tooth mobility, as TM-ILD values reflect qualitative (inflammatory status interpreted by BOP) and quantitative parameters (interpreted as the amount of CAL loss) of periodontal disease.

Is the Diagnosis of Generalized Stage IV (Severe) Periodontitis Compatible with the Survival of Extended Stabilizing Prosthetic Restorations? A Medium-Term Retrospective Study

The aim of the study was to identify the most relevant patient-related factors directly involved (alone or in combinations) in the long-term survival and functionality of the abutment teeth of extensive stabilizing bridges and removable prosthesis, in patients treated for Stage IV periodontitis, adhering to SPT over a period of at least 5 years. Seventy-six patients treated between 2000-2022, rehabilitated with FDPs and RDPs, adhering to SPT for at least 5 years were included. Patient-related factors influencing retention of RDPs and FDP, survival rates in regular (RCs) and irregular compliers (ICs), and incidence of biological and technical complications were assessed. During a follow-up of 69 months, from 57 patients with FDPs and 19 patients with RDPs, 39 (51.32%) were ICs, while 37 (48.68%) were RCs. An overall statistically significant association (p = 0.04) was identified between biological complications and the type of prostheses. The RDP patients had more complications than FDP patients. In 5.26% of the RDP patients, root caries were identified, and 10.53% were diagnosed with a periapical (endodontic) lesion, while 3.51% of the FDPS patients presented root caries. In five (6.57%) cases, abutment loss resulted in the loss of the prosthesis. Statistically significant correlations were observed between systemic diseases and tooth loss, and between type of tooth lost and the reason for tooth loss, irrespective of the type of prosthesis. A total of 66.67% of the lost incisors, 85.71% of the lost premolars, and 88.89% of the lost molars occurred due to periodontal causes. Furthermore, 93% of the FDPs and RDPs were still in place and in function.

Evaluation of furcation involvement with diagnostic imaging methods: a systematic review

OBJECTIVE

Multirooted teeth respond less favorably to non-surgical periodontal treatment and long-term tooth prognosis is influenced by the degree of furcation involvement (FI). Therapeutic strategy for multirooted teeth is essentially based on accurate diagnosis of the FI. The aim of this systematic review is to evaluate the accuracy of the different furcation assessment methods and to determine if radiographic help is needed to determine early stage of FI.

METHODS

Electronic databases were searched up to March 2021. Comparative studies describing the reliability of different clinical and/or radiological furcation assessment methods were identified.

RESULTS

A total of 22 studies comparing at least 2 furcation assessment methods, among which 15 retrospective studies, 5 prospective studies, 1 randomized controlled trial and 1 case series, were included in this review. The reliability of cone beam CT (CBCT), intraoral radiographs (IOs), orthopantomograms (OPGs) and MRI to identify FI was evaluated. Using OFS as a reference for FI detection and diagnosis, agreement ranged from 43.3 to 63% for OPG, 38.7 to 83.1% for IO and 82.4 to 84% for CBCT. The validity of the measurements was mainly influenced by the location of the furcation entrance. For radiological diagnosis, CBCT displayed the closest agreement with OFS while the accuracy of IO and OPG showed modest agreement and were influenced by the examiner's experience.

CONCLUSION

Altogether, it appears that the use of IO, OPG or CBCT allows detection of FI but could not be considered as gold-standard techniques.

The loss of molars in supportive periodontal care: a 10-year follow-up for tooth- and patient-related factors

AIM

Determining the impact of the degree of furcation involvement (FI) on the longevity of molar teeth and assessing risk variables (tooth- and patients-related factors) associated with loss of molars (LM) in individuals treated for periodontitis and monitored in a private program of supportive periodontal care (SPC).

MATERIALS AND METHODS

The present retrospective cohort study included 222 individuals with 1,329 molars under a 10-year monitoring period in SPC. Periodontal clinical parameters, FI, type of molar, pulp vitality and other variables of interest were colleted at approximately 50 days after active periodontal therapy and after 10 years. The association of tooth- and patients-related factors with LM was assessed using a multilevel Cox regression analysis.

RESULTS

235 molars were extracted during the SPC period of 12.4(±1.9) years. Age >50 years old, male gender, diabetes, smoking and no compliance were identified as relevant patient-related factors for LM during SPC (p<0.05). Significant tooth-related factors for LM were bleeding on probing (BOP) and probing depth (PD) ≥5mm, tooth non-vitality and class II and III FI (p<0.05).

CONCLUSIONS

Class III FI, tooth non-vitality, higher mean PD and BOP, age, male gender, diabetes and smoking all strongly influenced the prognosis of molars during SPC. This article is protected by copyright. All rights reserved.

Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation

When periodontal disease is diagnosed, it is difficult to predict the clinical response of treatment of a tooth over time because the result of treatment is affected by several factors and will depend on the maintenance and support of periodontal treatment. Rehabilitation with removable dental prostheses, fixed prostheses, and dental implants makes it possible to restore the function and esthetics of patients with tooth loss due to periodontal disease. The predictive factors of tooth loss in periodontitis patients should be assessed by dentists to inform their clinical decision-making during dental treatment planning. This will provide detailed individualized information and level of risk of patients considered suitable for dental rehabilitation. Therefore, the aim of this article was to review the subject of "Impact of tooth loss due to periodontal disease on the prognosis of rehabilitation" and the effect of fixed, removable, and implant-supported prostheses in periodontal patients.

Tooth loss and radiographic bone loss in patients without regular supportive care: A retrospective study

BACKGROUND

Very few studies have investigated the effect of patient and site factors on periodontal progression and long-term tooth loss in populations with minimal dental care. The aim of this retrospective study was to assess tooth loss and radiographic bone loss over at least 5 years in patients attending a national-health service primary care practice in Sicily and undergoing no regular care.

METHODS

Records of two hundred consecutive patients with at least 5 years follow-up were screened and demographic, clinical and radiographic data were retrieved. Analyses of associations between patient and site factors and tooth loss were performed.

RESULTS

After excluding not suitable patients, a total of 159 patient records with clinical and radiographic data with average 8.6 years follow-up were included. One hundred of these patients had no professional mechanical plaque removal (PMPR) carried out throughout the study follow-up. Nearly 65% of patients lost at least 1 tooth during the follow-up period, with a total of 400 extracted teeth (for periodontal and non-periodontal reasons). The annual tooth loss rate was slightly higher for "no PMPR" (untreated) patients (0.30 teeth/patient/year) compared with patients who had PMPR (0.27 teeth/patient/year). On a patient-level, only reduced frequency of daily tooth brushing was associated with tooth loss at logistic regression, whereas staging, grading and diagnosis of caries were associated with rates of tooth loss/year. At multilevel analysis including patient- and tooth-factors, age, diagnosis of caries and endodontic disease and percentage of bone loss at baseline were associated with tooth loss.

CONCLUSION

This study confirms the importance of tooth brushing, initial bone loss, caries and endodontic disease in predicting tooth survival in a primary care setting.

External validation and comparison of the predictive performance of 10 different tooth-level prognostic systems

AIM

Tooth-level prognostic systems can be used for treatment planning and risk assessment. This retrospective longitudinal study aimed to evaluate the prognostic performance of 10 different tooth-level risk assessment systems in terms of their ability to predict periodontal-related tooth loss (TLP).

MATERIALS AND METHODS

Data were retrieved retrospectively from patients who received surgical and non-surgical periodontal treatment. Data on medical history and smoking status at baseline and the last maintenance visit were collected. Ten tooth-level prognostic systems were compared using both univariate and multivariate Cox proportional hazard regression models to analyse the prognostic capability of each system for predicting TLP risk.

RESULTS

One-hundred and forty-eight patients with 3787 teeth, followed-up for a mean period of 26.5 ± 7.4 years, were evaluated according to 10 different tooth-level prognostic systems, making up a total of 37,870 individual measurements. All compared prognostic systems were able to stratify the risk of TLP at baseline when different classes of association were compared. After controlling for maintenance, age, and gender, all systems exhibited excellent predictive capacity for TLP with no system scoring a Harrell's C-index less than 0.925.

CONCLUSIONS

All tooth-level prognostic systems displayed excellent predictive capability for TLP. Overall, the Miller and McEntire system may have shown the best discrimination and model fit, followed by the Nunn et al. system.

Development of a prognostic tool: based on risk factors for tooth loss after active periodontal therapy

Objectives

The aim of this study was to develop a prognostic tool to estimate long-term tooth retention in periodontitis patients at the beginning of active periodontal therapy (APT).

Material and methods

Tooth-related factors (type, location, bone loss (BL), infrabony defects, furcation involvement (FI), abutment status), and patient-related factors (age, gender, smoking, diabetes, plaque control record) were investigated in patients who had completed APT 10 years before. Descriptive analysis was performed, and a generalized linear-mixed model-tree was used to identify predictors for the main outcome variable tooth loss. To evaluate goodness-of-fit, the area under the curve (AUC) was calculated using cross-validation. A bootstrap approach was used to robustly identify risk factors while avoiding overfitting.

Results

Only a small percentage of teeth was lost during 10 years of supportive periodontal therapy (SPT; 0.15/year/patient). The risk factors abutment function, diabetes, and the risk indicator BL, FI, and age (≤ 61 vs. > 61) were identified to predict tooth loss. The prediction model reached an AUC of 0.77.

Conclusion

This quantitative prognostic model supports data-driven decision-making while establishing a treatment plan in periodontitis patients. In light of this, the presented prognostic tool may be of supporting value.

Clinical relevance

In daily clinical practice, a quantitative prognostic tool may support dentists with data-based decision-making. However, it should be stressed that treatment planning is strongly associated with the patient’s wishes and adherence. The tool described here may support establishment of an individual treatment plan for periodontally compromised patients.

Retrospective long-term analysis of tooth loss over 20 years in a specialist practice setting: Periodontally healthy/gingivitis and compromised patients

OBJECTIVE

To assess tooth loss (TL) in initially periodontally healthy/gingivitis (PHG) and periodontally compromised (PC) individuals during a 15- to 25-year follow-up in a specialist practice and to identify the factors influencing TL.

MATERIALS AND METHODS

Patients were re-examined 240 ± 60 months after active periodontal therapy (PC) or initial examination (PHG). PHG patients were periodontally healthy or had gingivitis, and PC patients exhibited at least stage II periodontitis. TL, patient-related outcomes, and risk factors for TL were assessed at the patient level (group-relation, gender, age, smoking, bleeding on probing, educational status, mean number of visits/year).

RESULTS

Fifty-six PC patients receiving regular supportive periodontal care (12 female, mean age 49.1 ± 10.9 years, stage II: 10, stage III/IV: 46) lost 38 teeth (0.03 ± 0.05 teeth/year). Fifty-one PHG patients (23 female, mean age 34.5 ± 12.4 years) following regular oral prevention lost 39 teeth (0.04 ± 0.05 teeth/year) (p = .631). Both PC and PHG groups did not show any significant differences regarding visual analogue scale measurements [aesthetics (p = .309), chewing function (p = .362), hygiene (p = .989)] and overall Oral Health Impact Profile (p = .484). Age at the start of follow-up was identified as a risk factor for TL (p < .0001).

CONCLUSION

PC and PHG patients exhibited similarly small TL rates over 240 ± 60 months, which should, however, be interpreted with caution in view of the group heterogeneity. Clinical trial number: DRKS00018840 (URL: https://drks.de).

Magnetic resonance imaging as a diagnostic tool for periodontal disease: A prospective study with correlation to standard clinical findings-Is there added value?

AIM

To evaluate the correlation between standard clinical findings, radiographic (OPT) and magnetic resonance imaging (MRI) as well as to assess whether MRI is capable of providing additional information related to the severity and extent of periodontal disease.

METHODS

42 patients with generalized periodontitis received pre-interventional MRI scans. These were compared to MR images of a periodontal healthy control group (n = 34). The extent of the osseous oedema, detected by MRI, was set in correlation with clinical periodontitis-associated findings.

RESULTS

A highly significant correlation between bone oedema and clinical testings such as probing depth (p < 0.0001) and bleeding on probing (p < 0.0001) was revealed. The oedema exceeded the extent of demineralized bone. Patients with a positive BOP test showed a 2.51-fold increase in risk of already having a bone oedema around the respective tooth even if probing depth was ≤3 mm (logistic binary regression analysis, OR 2.51; 95% CI: 1.54-4.11; p < 0.0001).

CONCLUSION

MRI findings correlated with standard clinical findings, and MRI was able to depict intraosseous changes before any osseous defect had occurred.

Risk factors for tooth loss with a mean follow-up period of 13.9 years in supportive periodontal therapy patients

Background

Clinical evidence indicates that there are various risk factors of tooth loss. However, the degree of this risk among other risk factors remains unclear. In this retrospective cohort study, the authors evaluated the hazard ratios of several risk factors for tooth loss.

Methods

Included patients had all been treated for dental disorders, were in the supportive phase of periodontal therapy by dental hygienists, and visited a Japanese dental office continually during a 10-year period. Periodontal parameters, tooth condition, and general status of all teeth (excluding third molars) at the initial visit and at least 10 years later were evaluated by using multiple classification analysis.

Results

The authors evaluated a total of 7584 teeth in 297 patients (average age: 45.3, mean follow-up time: 13.9 years) Non-vital pulp was the most significant predictor of tooth loss according to Cox hazards regression analysis (hazard ratio: 3.31). The 10-year survival rate was approximately 90% for teeth with non-vital pulp and 99% for teeth with vital pulp. Fracture was the most common reason for tooth loss.

Conclusions

Non-vital pulp had the most significant association with tooth loss among the parameters. Therefore, it is very important to minimize dental pulp extirpation.

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.

Endpoints of active periodontal therapy

Aim

Position paper on endpoints of active periodontal therapy for designing treatment guidelines. The question was as follows: How are, for an individual patient, commonly applied periodontal probing measures—recorded after active periodontal therapy—related to (a) stability of clinical attachment level, (b) tooth survival, (c) need for re‐treatment or (d) oral health‐related quality of life.

Methods

A literature search was conducted in Ovid MEDLINE(R) and Epub Ahead of Print, In‐Process & Other Non‐Indexed Citations and Daily <1946 to 07 June 2019>.

Results

A total of 94 papers were retrieved. From the literature search, it was found that periodontitis patients with a low proportion of deep residual pockets after active periodontal therapy are more likely to have stability of clinical attachment level over a follow‐up time of ≥1 year. Other supporting literature confirms this finding and additionally reports, at the patient level, that probing pocket depths ≥6 mm and bleeding on probing scores ≥30% are risks for tooth loss. There is lack of evidence that periodontal probing measures after completion of active periodontal treatment are tangible to the patient.

Conclusions

Based on literature and biological plausibility, it is reasonable to state that periodontitis patients with a low proportion of residual periodontal pockets and little inflammation are more likely to have stability of clinical attachment levels and less tooth loss over time. Guidelines for periodontal therapy should take into consideration (a) long‐term tangible patient outcomes, (b) that shallow pockets (≤4 mm) without bleeding on probing in patients with <30% bleeding sites are the best guarantee for the patient for stability of his/her periodontal attachment, (c) patient heterogeneity and patient changes in immune response over time, and (d) that treatment strategies include lifestyle changes of the patient. Long‐term large population‐based and practice‐based studies on the efficacy of periodontal therapies including both clinical and patient‐reported outcomes (PROs) need to be initiated, which include the understanding that periodontitis is a complex disease with variation of inflammatory responses due to environment, (epi)genetics, lifestyle and ageing. Involving people living with periodontitis as co‐researchers in the design of these studies would also help to improve their relevance.

Early Tooth Loss after Periodontal Diagnosis: Development and Validation of a Clinical Decision Model

The aim of this study was to develop and validate a predictive early tooth loss multivariable model for periodontitis patients before periodontal treatment. A total of 544 patients seeking periodontal care at the university dental hospital were enrolled in the study. Teeth extracted after periodontal diagnosis and due to periodontal reasons were recorded. Clinical and sociodemographic variables were analyzed, considering the risk of short-term tooth loss. This study followed the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guidelines for development and validation, with two cohorts considered as follows: 455 patients in the development phase and 99 in the validation phase. As a result, it was possible to compute a predictive model based on tooth type and clinical attachment loss. The model explained 25.3% of the total variability and correctly ranked 98.9% of the cases. The final reduced model area under the curve (AUC) was 0.809 (95% confidence interval (95% CI): 0.629–0.989) for the validation sample and 0.920 (95% CI: 0.891–0.950) for the development cohort. The established model presented adequate prediction potential of early tooth loss due to periodontitis. This model may have clinical and epidemiologic relevance towards the prediction of tooth loss burden.

Massive data analyses show negative impact of type 1 and 2 diabetes on the outcome of periodontal treatment

Objectives

The aim was to evaluate the impact of diabetes on the outcome of periodontal treatment based on massive data analyses.

Materials and methods

Data originated from the database of a major German National Health Insurance. Patients who underwent periodontal treatment were allocated to four groups according to their medical condition: type 1 diabetes (D1), type 2 diabetes with the intake of oral anti-diabetics (D2M), type 2 diabetes without the intake of oral anti-diabetics (D2), and a control group without diabetes (ND). Four-year Kaplan-Meier survival analyses on the patient level and multivariate regression analyses were conducted for tooth extraction.

Results

Of 415,718 patients, 4139 matched the criteria for D1, 22,430 for D2M, and 23,576 for D2. At 4 years, the cumulative survival rate (no extraction) was 51.7% in the D1 group, 54.0% in the D2M group, and 57.7% in the D2 group. The ND control group had a significantly higher survival rate of 65.9% (P < 0.0001). In the multivariate analyses, both diabetes types were significantly associated with further tooth loss after periodontal treatment.

Conclusions

The diagnosis of diabetes type 1 or 2 seems to be associated with a higher risk of tooth loss after periodontal treatment.

Clinical relevance

The long-term prognosis of teeth in diabetes patients should be judged carefully.

A nomogram prediction for mandibular molar survival in Chinese patients with periodontitis: A 10-year retrospective cohort study

AIMS

To develop a nomogram prediction model of mandibular molar survival by comprehensively analysing clinical and radiographic risk factors of mandibular molar loss.

MATERIALS AND METHODS

Four hundred and seventy-eight mandibular molars of 139 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.1 years. The association of risk factors including clinical and radiographic parameters with mandibular molar loss was assessed using univariate and multivariate Cox regression analyses. A nomogram prediction model was developed, and the validation and discriminatory ability of it were analysed.

RESULTS

Hundred and four molars were lost in this study. Probing depth (PD), attachment loss (AL), furcation involvement (FI), bleeding on probing (BOP), tooth mobility and radiographic bone loss were significantly associated with tooth loss (p < .01). A gradient effect of degree of FI on mandibular molar loss existed increasing from degree Ⅱ (HR = 2.37, 95% CI: 1.48, 3.79) to Ⅲ (HR = 5.61, 95% CI: 3.01, 10.45) versus none & degree Ⅰ. The area under the curve (AUC) of the model was 0.891. The calibration curve and decision curve analysis demonstrated good performance and high net benefit of nomogram, respectively.

CONCLUSIONS

A specific nomogram could be adopted to predict the mandibular molar survival and formulate tailored treatment plans in Chinese.

Supportive Implant Therapy (SIT): A Prospective 10-Year Study of Patient Compliance Rates and Impacting Factors

The main objective of this study is to present patient compliance rates and influential factors for regular attendance in a systematic implant aftercare program (Supportive Implant Therapy; SIT) within a 10-year observation period. From 2005 to 2008, we identified 233 patients with 524 implants and implant-supported restorations at the study center. They had been instructed to attend an SIT program with 3-month recall intervals. A 2019 clinical prospective cohort study on 10-year compliance rates was performed. Data were assessed yearly in regression analyses to identify influential factors. Noncompliance rates increased during the period (4.8%, year 1; 39.7%, year 10). Total noncompliance was observed in four patients (1.7%) with 10 implants. “Age,” “Gender,” “Diabetes”, and “Surgical case complexity” showed no correlation with patient compliance. “Smoking” and “Cardiovascular diseases” significantly influenced patients in one of ten years, while “Number of implants per patient”, “Type of implant-supported prostheses”, and “Pre-existing experience in a prophylaxis program” reached significance after several years. When patients with implant-supported restorations are strongly recommended and frequently remotivated to comply with an SIT program with 3-month recall, an approximately 60% compliance rate after 10 years is achievable. Previous prophylaxis program experience, increased number of implants per patient, and removable implant-supported prostheses may be strong influential factors for increased patient compliance.

Influence of retainer and major connector designs of removable partial dentures on the stabilization of mobile teeth: A preliminary study

The purpose of this study was to investigate the influence of retainers and major connector designs on the stabilization of remaining mobile teeth using removable partial dentures (RPDs). We prepared experimental RPDs with several retainer designs and major connectors for lower Kennedy class I models. The simulated RPD insertion and removal test was conducted and retentive force and mobility of mobile remaining teeth with and without RPD placement were measured throughout a simulation test. Regardless of reduction of retentive force, the placement of RPDs using cast clasps and/or lingual plates resulted in reduced mobility of the remaining teeth than use of wrought wire clasps and/or lingual bars. The results suggested that cast clasps and lingual plates are effective for the stabilization of mobile, remaining teeth. Additionally, the stabilizing effect of RPD on abutment teeth was not diminished, despite decreases in retentive force.

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.

Predictors for tooth loss in periodontitis patients: Systematic review and meta-analysis

AIM

A range of predictors for tooth loss in periodontitis patients have been reported. We performed a systematic review and meta-analysis to assess the consistency and magnitude of any association between a total of 12 predictors and tooth loss.

MATERIALS AND METHODS

Medline/Embase/Central were searched for longitudinal studies investigating the association between predictors and tooth loss in periodontitis patients. Random-effects meta-analysis was performed, and study quality assessed.

RESULTS

Twenty studies (15,422 patients, mean follow-up: 12 years) were included. The mean annual tooth loss/patient was 0.12 (min./max: 0.01/0.36). Older patients (n = 8 studies; OR: 1.05, 95% CI: 1.03-1.08/year), non-compliant ones (n = 11; 1.51, 1.06-2.16), diabetics (n = 7; 1.80, 1.26-2.57), those with IL-1-polymorphism (n = 3; 1.80; 1.29-2.52) and smokers (n = 15; 1.98, 1.58-2.48) had a significantly higher risk of tooth loss. Teeth with bone loss (n = 3; 1.04, 1.03-1.05/%), high probing pocket depth (n = 6; 3.19, 1.70-5.98), mobility (n = 4; 3.71, 1.65-8.38) and molars (n = 4; 4.22, 2.12-8.39), especially with furcation involvement (n = 5; 2.68, 1.75-4.08) also showed higher risks. Gender (n = 16; 0.95, 0.86-1.05) and endodontic affection (n = 3; 3.62, 0.99-13.2) were not significantly associated with tooth loss.

CONCLUSIONS

Older, non-compliant, smoking or diabetic patients, and teeth with bone loss, high probing pocket depth, mobility, or molars, especially with furcation involvement showed higher risks of tooth loss.

Impact of compliance during periodontal maintenance therapy on oral health-related quality of life: A 6-year follow-up

OBJECTIVE

To evaluate the effects of compliance during periodontal maintenance therapy (PMT) in the oral impact on daily performance (OIDP) measures, as well as to determine and compare the periodontal condition of acceptable and irregular compliers.

MATERIAL AND METHODS

From a 6-year prospective cohort study with 268 individuals under PMT, 232 individuals had complete periodontal clinical data and OIDP questionnaires completed between T1 (data was recorded after the first PMT appointment) and T2 (final data at the last PMT appointment), were determined to be eligible. Individuals were divided into two groups: 124 acceptable compliers (AC) and 108 irregular compliers (IC). Full-mouth periodontal examination and questionnaires were evaluated in 2 times, at T1 and T2.

RESULTS

At T2, the periodontal status of the AC group was significantly better than the IC group. The IC group also presented with higher OIDP scores (63.31 ± 19.11) compared to the AC group (57.72 ± 15.30, p = 0.005). On analyzing the OIDP dimensions independently, both groups (AC and IC) presented with high scores in the functional, psychological and social performances; however, the impacts were significantly higher in IC group.

CONCLUSION

The AC group presented with better periodontal conditions and lower OIDP, compared to the IC group. The discomfort and dissatisfaction with appearance, showed more influence on these daily impacts.

CLINICAL SIGNIFICANCE

Acceptable compliers showed lower scores of OIDP when compared to erratic ones. Thus, clinicians could take the chance to gain advantage from the positive impacts of acceptable compliance in the OHRQL for subsequent patient-centred motivation during PMT.

Predictive factors for tooth loss during supportive periodontal therapy in patients with severe periodontitis: a Japanese multicenter study

Background

Supportive periodontal therapy (SPT) must take individual patient risk factors into account. We conducted a multicenter joint retrospective cohort study to investigate the value of modified periodontal risk assessment (MPRA) and therapy-resistant periodontitis (TRP) assessment as predictive factors for tooth loss due to periodontal disease in patients with severe periodontitis during SPT.

Methods

The subjects were 82 patients from 11 dental institutions who were diagnosed with severe periodontitis and continued SPT for at least 1 year (mean follow-up = 4.9 years) between 1981 and 2008. The outcome was tooth loss due to periodontal disease during SPT. The Cox proportional hazards model was used to analyze sex, age, diabetes status, smoking history, number of periodontal pockets measuring ≥6 mm, rate of bleeding on probing, bone loss/age ratio, number of teeth lost, MPRA, and TRP assessment as explanatory variables.

Results

Univariate analysis showed that loss of ≥8 teeth by the start of SPT [hazard ratio (HR) 2.86], MPRA score indicating moderate risk (HR 8.73) or high risk (HR 11.04), and TRP assessment as poor responsiveness to treatment (HR 2.79) were significantly associated with tooth loss (p < 0.05). In a model in which the explanatory variables of an association that was statistically significant were added simultaneously, the HR for poor responsiveness to treatment and ≥8 teeth lost was significant at 20.17 compared with patients whose TRP assessment indicated that they responded favorably to treatment and who had lost <8 teeth by the start of SPT.

Conclusion

MPRA and TRP assessment may be useful predictive factors for tooth loss due to periodontal disease during SPT in Japanese patients with severe periodontitis. Additionally, considering the number of teeth lost by the start of SPT in TRP assessment may improve its predictive accuracy.

Number of Non-vital Teeth as Indicator of Tooth Loss during 10-year Maintenance: A Retrospective Study

The purpose of this study was to investigate whether number of non-vital teeth was an indicator of tooth loss during maintenance. Thirty-three general practitioners provided data on 321 patients undergoing maintenance over 10 years. The number of present teeth (PT), smoking status, level of bone loss, number of non-vital teeth, and reason for tooth loss during that period were investigated. Multiple logistic regression was performed to identify whether the number of non-vital teeth was associated with tooth loss. The average number of lost teeth was 1.07±1.82; that of PT at baseline was 24.4±3.9; and that of non-vital teeth at baseline was 5.4±4.5. Multiple logistic regression revealed a significant association between >8 non-vital teeth and tooth loss during maintenance (odds ratio [OR]: 2.40; 95% confidence interval [CI]: 1.18-4.87). It also demonstrated relationships between >8 non-vital teeth and root fracture or caries (OR: 3.90; 95%CI: 1.68-9.03 or OR: 2.85, 95%CI: 1.14-7.10, respectively). The number of non-vital teeth was associated with tooth loss during maintenance. The results suggest that patients with many non-vital teeth before commencement of maintenance are particularly at risk of tooth loss due to root fracture or caries. Therefore, the number of non-vital teeth offers a useful indicator of potential tooth loss.

Predictors of long-term outcomes in patients undergoing periodontal maintenance

AIM

This retrospective study aimed to characterize the baseline status of patients following periodontal maintenance, analysing the association between the long-term outcome of these patients, smoking, bruxism, and the main clinical and radiographic variables.

MATERIAL AND METHODS

A sample of 174 patients with moderate to severe periodontitis was refined into homogeneous subsamples according to smoking and bruxism and the rate of tooth loss due to periodontal disease (TLPD): 0, 1-2, and >2 teeth. The association and the distribution (χ² test) of the variables within the subsamples were analysed.

RESULTS

Smoking and bruxism were significantly associated with higher TLPD rates. Vertical and circumferential bone defects (p < .0001), and abfractions (p < .0001) were associated with bruxism and particularly with bruxism and TLPD >2. Furcation defects (p = .0002), fewer radio-opaque subgingival calculus (χ² p < .0001), a lower mean Gingival index (χ² p = .027), and increased mean recessions >1.5 mm (χ² p = .0026) were associated with smoking and higher TLPD rates. The mean baseline mobility, abfractions, and recessions characterized two basic types of TLPD.

CONCLUSIONS

Smoking, bruxism, and routine clinical and radiological parameters can be used to characterize the baseline status of patients with worse outcomes.

Interleukin-6 and interleukin-10 gene polymorphisms and the risk of further periodontal disease progression

Susceptible genotypes to periodontal disease are associated with disease onset and progression. The aim of this study was to examine the effect of gene polymorphisms on the risk of further disease progression and the need for further treatment among adults with chronic periodontal disease. Sixty-seven patients diagnosed with chronic periodontitis were grouped according to genotype status and risk of further progression of disease and tooth loss. All individuals were clinically evaluated for probing pocket depth, clinical attachment loss and bleeding on probing at baseline and 45 days after treatment. Blood samples were collected at baseline and genotyping of the polymorphisms in IL-6 (rs1800796) and IL-10 (rs1800872) genes were performed by PCR. Following DNA separation and genotyping, 65.7% of the patients were homozygous carriers of the IL-6 -572G and 49.3% were carriers of the IL-10 -592A allele. Individuals at risk of disease progression ranged from 7.5% to 62.7% based on the criteria used. Carriers of the IL-10 -592A allele were significantly associated with BOP ≥ 30% and therefore exhibited a higher risk of further periodontal breakdown (p = 0.018) with an odds ratio of 1.18. None of the other definitions of disease progression were significantly associated with the examined IL-6 and IL-10 genotypes (p > 0.05). IL-10 polymorphism was associated with an increased risk of further disease progression and the potential need for further treatment following non-surgical periodontal treatment. Susceptible IL-6 genotypes were not associated with the risk of persisting or recurrent disease activity.

Introduction of a prediction model to assigning periodontal prognosis based on survival time

AIMS

To develop a prediction model for tooth loss due to periodontal disease (TLPD) in patients following periodontal maintenance (PM), and assess its performance using a multicentre approach.

MATERIAL AND METHODS

A multilevel analysis of eleven predictors of TLPD in 500 patients following PM was carried out to calculate the probability of TLPD. This algorithm was applied to three different TLPD samples (369 teeth) gathered retrospectively by nine periodontist, associating several intervals of probability with the corresponding survival time, based on significant differences in the mean survival time. The reproducibility of these associations was assessed in each sample (One-way ANOVA and pairwise comparison with Bonferroni corrections).

RESULTS

The model presented high specificity and moderate sensitivity, with optimal calibration and discrimination measurements. Seven intervals of probability were associated with seven survival time and these associations contained close to 80% of the cases: the probability predicted the survival time at this percentage. The model performed well in the three samples, as the mean survival time of each association were significantly different within each sample, while no significant differences between the samples were found in pairwise comparisons of means.

CONCLUSIONS

This model might be useful for predicting survival time in different TLPD samples.

Root abnormalities and nonsurgical management of generalized aggressive periodontitis

To investigate long-term nonsurgical treatment outcomes in patients with generalized aggressive periodontitis (GAgP) and the impact of root abnormalities (RAs) and other patient-level factors in relation to GAgP progression. Patients (n = 64) from a GAgP cohort who completed active nonsurgical periodontal treatment and consented to re-evaluation after 3 to 11 (mean 5.3) years, were enrolled. RAs were identified using radiographs. Periodontal parameters (e.g., probing depths [PDs], and tooth loss [TL]) were investigated. Multivariate analysis was performed to identify factors contributing to TL and bone level alteration (∆BL). After treatment, the mean number of sites with PDs > 5 mm decreased from 54.3 to 17.2. Annual TL was 0.11/patient. Twenty-one patients (32.8%) had >4 teeth with root abnormalities (RA-teeth) and exhibited a higher risk for TL (univariate odds ration [OR] = 3.52, multivariate logistic OR = 6.57). Factors correlated to ∆BL were sites with residual PD > 5 mm (β = -0.400) and observation time (β = -0.210). Nonsurgical treatment provides beneficial outcomes in GAgP patients. Higher incidence of RAs and high prevalence of residual deep pockets have a negative impact on long-term outcomes.

PRACTICAL IMPLICATIONS

in cases of GAgP with residual deep pockets and high incidence of RAs, clinicians must emphasize that long-term outcomes of nonsurgical treatment may be compromised.

Characteristics of cellular composition of periodontal pockets

Purpose

The development of inflammatory periodontal disease in young people is an urgent problem of today's periodontology, and requires a development of new methods that would give an opportunity not only to diagnose but also for prognosis of periodontitis course in a given patients contingent.

Results

Cellular structure of periodontal pockets is presented by hematogenous and epithelial cells. Our results are confirmed by previous studies, and show that the penetration of periodontal pathogens leads to formation in periodontal tissue of a highly active complex compounds—cytokines that are able to modify the activity of neutrophils and reduce their specific antibacterial properties. Cytokines not only adversely affect the periodontal tissues, but also cause further activation of cells that synthesized them, and inhibit tissue repair and process of resynthesis of connective tissue by fibroblasts.

Conclusion

Neutrophilic granulocytes present in each of the types of smear types, but their functional status and quantitative composition is different. The results of our cytological study confirmed the results of immunohistochemical studies, and show that in generalized periodontitis, an inflammatory cellular elements with disorganized epithelial cells and connective tissue of the gums and periodontium, and bacteria form specific types of infiltration in periodontal tissues.

Endodontic status and retention of molars in periodontally treated patients: results after 10 or more years of supportive periodontal therapy

OBJECTIVES

To assess the influence of endodontic status on retention of molars in patients under supportive periodontal treatment (SPT).

MATERIAL & METHODS

A total of 136 subjects with 1015 molars at baseline were examined retrospectively, including 188 endodontically treated molars in 90 patients. Multilevel Cox regression analysis identified factors contributing to loss of molars.

RESULTS

Root canal treatments contributed significantly to loss of molars during on average 13.2 years of SPT (Hazard ratio: 2.98, 95% CI: 1.74-5.1, p < 0.001). Endodontic treatment was more frequently present in first molars (p < 0.001) and in the maxilla (p = 0.01). In endodontically treated molars, degree III furcation involvement could be detected more often compared to molars without root canal treatment (p < 0.001). Among the root canal-treated molars, several patient and tooth-related factors showed an impact on tooth retention, but only molars with a periapical index of 4 and 5 (labelled "diseased") were significantly more often lost.

CONCLUSION

The retention of molars in periodontally compromised patients after periodontal treatment is influenced by periodontal as well as endodontal factors. On a long-term basis, it is feasible to retain these teeth via active periodontal treatment and SPT for more than 10 years.