The 2018 classification of periodontal diseases. Its predictive value for tooth loss

Evaluating the Performance and Implementation of the 2018 Classification of Periodontal Diseases: A Systematic Review and Survey

AIM

To evaluate the performance and implementation of the 2018 Classification of Periodontal Diseases for periodontitis through systematic review and survey methodology.

MATERIALS AND METHODS

A two-part systematic review was conducted. Part 1 aimed, with descriptive statistics, to evaluate performance metrics of the 2018 Classification, including diagnostic accuracy, prognostic performance and examiner reliability. Part 2 used thematic analysis to elucidate facilitators and barriers to the implementation of the classification. A survey collected evidence of barriers, facilitators and local implementation.

RESULTS

Part 1 of this review included 14 individual studies of moderate risk of bias. Eight studies examined diagnostic accuracy, three studies examined prognostic efficacy and three studies examined inter-/intra-rater reliability. Part 2 included 33 individual studies with data considered at high risk of bias. The survey returned 1113 responses. The thematic analysis in Part 2 led to seven findings, five related to facilitators and two concerning barriers to the implementation. Survey results showed that 78% of respondents currently use the classification, but the most common concerns relate to its complexity.

CONCLUSIONS

The 2018 Classification performs well as a classification in comparison with previous classifications. Specific identified barriers have potentially limited the comprehensive uptake of the classification.

Implementation of Chief Complaint-Based Clinical Reasoning Training in Periodontal Internships

BACKGROUND

The gap between theoretical knowledge and clinical skills highlights the need for clinical reasoning training curriculum in periodontal education, especially in periodontal internships. This study aims to develop a Chief Complaint-Based Clinical Reasoning Training (CCB-CRT) program and evaluate its impact on periodontal interns' clinical reasoning abilities and overall performance.

METHODS

The CCB-CRT program was developed based on eight common chief complaints (CCs) identified through surveys of periodontal specialists and an analysis of patient visit data from a university-affiliated hospital's periodontal clinic. The study involved a comparison between a control group of fifth-year dental students (2021) and a CCB-CRT group (2022). Both groups completed an 8-week training course. The CCB-CRT group received additional training focused on the 8 common CCs, using student-led discussions, flipped classroom, mind mapping, and presentations. Evaluation criteria included overall performance, disease diagnosis and treatment plan, misdiagnosis rates, and students' satisfaction.

RESULTS

After 1 year of CCB-CRT implementation, participants in the CCB-CRT group showed substantial improvements in overall performance, diagnostic accuracy, and satisfaction compared to traditional teaching methods. The program enhanced students' understanding of theoretical knowledge, improved their interpretation of clinical manifestations and examination results, and enhanced their clinical reasoning skills and diagnostic accuracy.

CONCLUSIONS

The successful application of the CCB-CRT program in periodontology education demonstrates its efficacy in improving clinical reasoning skills and diagnostic efficiency among students. The structured approach facilitates the transition from theoretical knowledge to practical application, contributing to better patient care in periodontal practice.

Effectiveness of a novel amine + zinc + fluoride toothpaste in reducing plaque and gingivitis: results of a six-month randomized controlled trial

OBJECTIVES

To evaluate the efficacy of a toothpaste containing amine compound, 0.5% zinc lactate, and 1400 ppm F (NaF) in comparison to a regular fluoride toothpaste containing 1450 ppm F as MFP/NaF (negative control). Plaque and gingivitis indices were determined over a 6-month period.

MATERIALS AND METHODS

In a randomized, double-blind, two-cell, parallel-group design on healthy adults from the Bangkok, Thailand area presenting with initial gingivitis (Löe-Silness gingival index ≥ 1) and visible plaque (Turesky Modification-Quigley-Hein index ≥ 1.5) were assigned test and negative control toothpastes and instructed to brush twice daily for two minutes.

RESULTS

Site-level (N = 10,778) and subject-level (N = 92) data indicated that the test toothpaste increased the number of healthy sites and improved gum health as compared to the negative control toothpaste. For the test group, after 6 months, the average reduction for plaque, gingival index, and gingival severity was 31.2%, 32.3%, and 49.3%, respectively. Average reductions were greater in the test group than the negative control group across all measures.

CONCLUSIONS

The amine + zinc + fluoride toothpaste significantly improved measures of plaque (12× more effective) and gingivitis (5× more effective) in comparison to a standard fluoride toothpaste, suggesting that the novel formulation with antibacterial active ingredients amine and zinc facilitates more effective plaque removal, and promotes gingival health.

CLINICAL RELEVANCE

These results suggest that daily use of amine + zinc + fluoride toothpaste can provide a significant improvement in managing plaque accumulation and bleeding associated with gingival inflammation especially for patients experiencing gingivitis.

CLINICAL TRIAL REGISTRATION

NCT06563518 (registration date: August 19, 2024).

Correlation of serum vitamin D and IL-8 to stages of periodontitis: a case-control analysis

OBJECTIVES

The current literature lacks the correlation between serum levels of vitamin D and interleukin-8 (IL-8) to the stages of periodontitis. The present research objectives are to evaluate the serum levels of vitamin D and IL-8 in periodontitis participants and healthy controls and to measure their correlation with the stages of periodontitis.

METHODS

The current case-control study was conducted on patients with periodontitis and healthy controls. After obtaining a questionnaire from the participants, the following clinical parameters were measured; periodontal probing depth (PPD), clinical attachment loss (CAL), plaque index (PI), gingival index (GI), bleeding on probing (BOP), and tooth count. The serum levels of vitamin D and IL-8 were measured using ELISA kits. Then, we measured the correlation of the stages of periodontitis with the serum levels of vitamin D and IL-8.

RESULTS

Ninety-eight participants; 52 with periodontitis and 46 healthy controls were included. The patients with periodontitis showed a significantly lower level of vitamin D, higher PPD, CAL, BOP, and lower number of teeth than the controls. In addition, serum vitamin D significantly correlated with the stages of periodontitis. Serum IL-8 showed no significant difference between the study and control groups while it does not significantly correlate with the stages of periodontitis.

CONCLUSION

The current study's findings suggest a potential association between serum level of vitamin D with severity of periodontitis which necessitates screening vitamin D status in patients with periodontitis and investigating the possibility of vitamin D supplementation in decreasing the progression of periodontitis.

Healthy lifestyles ameliorate an increased risk of periodontitis associated with polycyclic aromatic hydrocarbons

The risk of chronic inflammatory diseases has been linked to exposure to polycyclic aromatic hydrocarbons (PAHs). However, limited data are available regarding their impact on periodontitis. This study aims to explore the association between PAHs and periodontitis while also evaluating the potential modifying effects of healthy lifestyles. We included 17,031 participants from the US National Health and Nutrition Examination Survey (NHANES, 2001-2004 and 2009-2014). A meta-analysis-based environment-wide association study (EWAS) was adopted to identify environmental chemicals for the mean probing pocket depth (PPD) and the mean attachment loss (AL). PAHs were further evaluated concerning the cross-sectional association with Mod/Sev periodontitis using multivariable logistic regression models. Moreover, healthy lifestyle scores were estimated to assess their modifying effect on the PAH-periodontitis association. EWAS analysis identified several urinary PAH metabolites as significant risk factors for the mean PPD and AL (false discovery rate <0.05, Q > 0.05). Periodontitis severity was positively associated with eight individual and total PAH concentrations. Stratifying the participants in terms of healthy lifestyle scores did not reveal any association in the healthy group. Moreover, the association weakened in never-smokers and individuals with sufficient physical activity and normal weight. PAH exposure was a risk factor for periodontitis. A healthier lifestyle was observed to offset the risk potentials of PAHs for periodontitis. Smoking cessation, physical activity, and weight loss might be recommended as a healthy lifestyle strategy for ameliorating PAH-related periodontitis.

Prunin Laurate Derived from Natural Substances Shows Antibacterial Activity against the Periodontal Pathogen Porphyromonas gingivalis

Periodontal disease is an inflammatory disease caused by infection with periodontopathogenic bacteria. Oral care is essential to prevent and control periodontal disease, which affects oral and systemic health. However, many oral hygiene products currently on the market were developed as disinfectants, and their intense irritation makes their use difficult for young children and older people. This study investigated the antibacterial effects of prunin laurate (Pru-C12) and its analogs on periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis). Pru-C12 and its analogs inhibited in vitro bacterial growth at more than 10 μM and biofilm formation at 50 µM. Among its analogs, only Pru-C12 showed no cytotoxicity at 100 µM. Three of the most potent inhibitors also inhibited the formation of biofilms. Furthermore, Pru-C12 inhibited alveolar bone resorption in a mouse experimental periodontitis model by P. gingivalis infection. These findings may be helpful in the development of oral hygiene products for the prevention and control of periodontal disease and related disorders.

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 residual pockets on periodontal tooth loss: A retrospective analysis

BACKGROUND

Individuals enrolled in supportive periodontal therapy (SPT) can still present with tooth loss due to periodontitis (TLP). There is limited evidence on the influence of residual pockets (RPc) and a defined "threshold" at which a patient's profile is set to be at high risk for TLP in the literature. Therefore, this study aimed to assess the influence of RPc on TLP and determine the prognostic performance of RPc compared to the staging and grading of periodontitis on TLP risk.

METHODS

Clinical data from 168 patients (3869 teeth) treated for periodontitis and receiving SPT for at least 10 years were evaluated in this retrospective study. TLP and the percentage of sites with RPc ≥ 5 mm or ≥6 mm per patient were collected. The prognostic performance of RPc was compared to the staging and grading of the disease on TLP using a multilevel Cox proportional hazard regression model.

RESULTS

Over a median follow-up of 25 years, 13.7% of teeth were lost, 4.6% of which were due to periodontitis. Most patients with TLP had ≥1 site with RPc ≥5 mm (90.8%) or ≥6 mm (77.6%). Multivariate multilevel Cox regression revealed that patients with >15% of sites with RPc ≥5 mm had a hazard ratio of 2.34, and grade C had a hazard ratio of 4.6 for TLP compared to RPc ≤4 mm/grade A. Grading exhibited the best discrimination and model fit.

CONCLUSION

Patients with RPc ≥5 mm at >15% of the sites are at risk for tooth loss. Grading and RPc ≥5 mm displayed very good predictive capability of TLP.

ACES: A new framework for the application of the 2018 periodontal status classification scheme to epidemiological survey data

AIM

To propose a framework for consistently applying the 2018 periodontal status classification scheme to epidemiological surveys (Application of the 2018 periodontal status Classification to Epidemiological Survey data, ACES).

PROPOSED FRAMEWORK

We specified data requirements and workflows for either completed or planned epidemiological surveys, utilizing commonly collected measures of periodontal status (clinical attachment levels [CAL], probing depths, bleeding on probing), as well as additional necessary variables for the implementation of the 2018 periodontal status classification (tooth loss due to periodontitis and complexity factors). Following detailed instructions and flowcharts, survey participants are classified as having periodontal health, gingivitis or periodontitis. Rates of edentulism must also be reported. In cases of periodontitis, instructions on how to compute the stage and extent are provided. Assessment of grade can be derived from CAL measurements (or from radiographic alveolar bone loss data) in relation to root length and the participant's age.

CONCLUSIONS

ACES is a framework to be used in epidemiological studies of periodontal status that (i) have been completed, and in which stage and grade according to the 2018 classification are inferred retroactively, or (ii) are being planned. Consistent use of the proposed comprehensive approach will facilitate the comparability of periodontitis prevalence estimates across studies.

Identifying predictors of the tooth loss phenotype in a large periodontitis patient cohort using a machine learning approach

OBJECTIVES

This study aimed to identify predictors associated with the tooth loss phenotype in a large periodontitis patient cohort in the university setting.

METHODS

Information on periodontitis patients and nineteen factors identified at the initial visit was extracted from electronic health records. The primary outcome is tooth loss phenotype (presence or absence of tooth loss). Prediction models were built on significant factors (single or combinatory) selected by the RuleFit algorithm, and these factors were further adopted by regression models. Model performance was evaluated by Area Under the Receiver Operating Characteristic Curve (AUROC) and Area Under the Precision-Recall Curve (AUPRC). Associations between predictors and the tooth loss phenotype were also evaluated by classical statistical approaches to validate the performance of machine learning models.

RESULTS

In total, 7840 patients were included. The machine learning model predicting the tooth loss phenotype achieved AUROC of 0.71 and AUPRC of 0.66. Age, periodontal diagnosis, number of missing teeth at baseline, furcation involvement, and tooth mobility were associated with the tooth loss phenotype in both machine learning and classical statistical models.

CONCLUSIONS

The rule-based machine learning approach improves model explainability compared to classical statistical methods. However, the model's generalizability needs to be further validated by external datasets.

CLINICAL SIGNIFICANCE

Predictors identified by the current machine learning approach using the RuleFit algorithm had clinically relevant thresholds in predicting the tooth loss phenotype in a large and diverse periodontitis patient cohort. The results of this study will assist clinicians in performing risk assessment for periodontitis at the initial visit.

Periodontitis in young individuals: Important factors for disease progression

AIM

To investigate the progression of periodontitis in young individuals and identify factors that contribute to progression rate and whether periodontitis stage and grade have an impact on disease progression.

MATERIALS AND METHODS

This retrospective cohort study was based on patients younger than 36 years at two periodontal clinics between 2003 and 2009. At least 10 years later, a clinical and radiographic examination was performed on 215 patients. The marginal bone loss between baseline and follow-up for the tooth with the most severe bone loss at follow-up was estimated by radiographic measurements. Linear regression analysis was used to investigate the influence of potential risk indicators on periodontitis progression.

RESULTS

Most patients (83%) were classified as periodontitis stage III at baseline. At follow-up, 70% of these patients remained in stage III. The frequency of patients with grade C decreased from 79% to 17% at follow-up. The median (Q25%; Q75%) of the longitudinal marginal bone loss was 0.5 mm (0.0; 2.0). High bleeding on probing (BOP) index at baseline, smoking and interruption of periodontal treatment were found to significantly increase longitudinal bone loss.

CONCLUSIONS

High levels of BOP at baseline, smoking and interruption of periodontal treatment increased the risk of marginal bone loss. The stage and grade at baseline had no significant impact on disease progression.

Justification for the 2017 periodontitis classification in the light of the Checklist for Modifying Disease Definitions: A narrative review

Once a while, disease classifications have needed revision because new knowledge has accumulated, and new technologies and better treatments have emerged. Changes made to disease classifications should be trustworthy and openly justified. The periodontitis definition and classification system was changed in 2017 by the 'World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions'. The workshop, comprising clinicians and researchers, resulted in the production of a 23-article special issue that introduced the new definitions and classifications of periodontitis. In this narrative review, we critically review how the changes made to the periodontitis definition and classification were justified in the light of the Checklist for Modifying Disease Definitions. Under each of the eight items of the checklist, we have discussed how the item was or could have been considered in the light of the checklist and its guidance. In our view, the new definition and classification of periodontitis was presented in an understandable way, even though the changes from the previous definition were not made visible. However, the issues of (1) estimated changes in prevalence or incidence, (2) triggers for the change, (3) prognostic ability, (4) repeatability or reproducibility, (5) incremental benefits, (6) incremental harms or (7) net benefits and harms related to the introduction of new classification were not considered in the way suggested in the checklist. Thereby, a balanced assessment of potential benefits and harms associated with the new periodontitis classification system was not presented, and to a large extent it remains unknown if the use of the new classification system will provide more net benefits to patients and to the community than previous systems. It is our view that patients and societies deserve transparent and balanced assessments of the potential benefits and harms associated with the periodontitis classification. Importantly, these should reflect the values and preferences also of the patients and the wider community and consider the impact on resource usage.

Clinical benefits of systemic amoxicillin/metronidazole may depend on periodontitis stage and grade: An exploratory sub-analysis of the ABPARO trial

AIM

Assessment of treatment response after systemic amoxicillin/metronidazole adjunctive to subgingival instrumentation (SI) according to stages and grades of the 2018 classification of periodontal diseases.

MATERIALS AND METHODS

We carried out exploratory re-analysis of the placebo-controlled, multi-centre ABPARO trial (52; 45/60 years of age; 205 males, 114 active smokers). Patients were randomized to SI with systemic amoxicillin 500 mg/metronidazole 400 mg (three times a day for 7 days, n = 205; ANTI) or placebo (n = 200; PLAC) and maintenance therapy every 3 months. Patients were reclassified according to the 2018 classification (stage/extent/grade). Treatment effect was the percentage of sites per patient with new attachment loss ≥1.3 mm (PSAL ≥ 1.3 mm) at 27.5 months post-baseline/randomization.

RESULTS

All patients were assigned according to the stage (n = 49 localized stage III, n = 206 generalized stage III, n = 150 stage IV). Because of missing radiographs, only 222 patients were assigned to grades (n = 73 B, n = 149 C). Treatment (PLAC/ANTI) resulted in PSAL ≥ 1.3 mm (median; lower/upper quartile) in localized stage III (PLAC: 5.7; 3.3/8.4% vs. ANTI: 4.9; 3.0/8.3%; p = .749), generalized stage III (8.0; 4.5/14.3% vs. 4.7; 2.4/9.0%; p < .001), stage IV (8.5; 5.1/14.4% vs. 5.7; 3.3/10.6%; p = .008), grade B (4.4; 2.4/6.7% vs. 3.6; 1.9/4.7%; p = .151) and grade C (9.4; 5.3/14.3% vs. 4.8; 2.5/9.4%; p < .001).

CONCLUSIONS

In generalized periodontitis stage III/grade C, a clinically relevant lower percentage of disease progression after adjunctive systemic amoxicillin/metronidazole was observed compared to placebo (PLAC: 9.7; 5.8/14.3% vs. ANTI: 4.7; 2.4/9.0%; p < .001).

Risk factors for tooth loss and progression of periodontitis in patients undergoing periodontal maintenance therapy

AIM

The aim of this study was to investigate patient- and tooth-level factors that may predict tooth loss and periodontitis progression in patients who have undergone at least 5 years of periodontal maintenance.

MATERIALS AND METHODS

In this retrospective cohort study, 135 patients were examined after active periodontal therapy (APT) and periodontal maintenance for 5.09-8.65 years (mean 6.16 ± 0.74 years). Regression models were applied to identify risk factors associated with tooth loss and disease progression.

RESULTS

Stage IV periodontitis (incidence rate ratio [IRR] = 4.61; 95% confidence interval, CI [2.97-7.18], p < .001), the presence of ≥5 sites with probing pocket depth (PPD) ≥5 mm at the end of APT (IRR = 2.04; 95% CI [1.32-3.20], p < .01), and residual PPD ≥7 mm at the end of APT (odds ratio [OR] = 3.01; 95% CI [1.14-7.94], p < .05) were risk factors for tooth loss. Residual PPDs of 5 mm (OR = 2.02; 95% CI [1.20-3.40], p < .01) and 6 mm (OR = 2.41; 95% CI [1.22-4.76], p < .05) at the end of APT were risk factors for disease progression. Above 3 mm, each 1 mm increase in maximum PPD/clinical attachment loss was associated with an increased risk of tooth loss and disease progression.

CONCLUSIONS

Stage IV periodontitis is associated with an increased risk of tooth loss. Teeth with PPD ≥5 mm at the end of APT are at risk of periodontitis progression or tooth loss.