Guest Editorial: Clarifications on the use of the new classification of periodontitis

Tooth- and implant-related prognostic factors in treatment planning

Following a comprehensive patient examination, including the assessment of periodontal and peri-implant diseases as well as considering the patient's needs, a pretherapeutic prognosis for each tooth and implant is given. Teeth and implants with a secure pretherapeutic prognosis require simple procedures and may be regarded as secure abutments for function and with a doubtful pretherapeutic prognosis usually need a comprehensive therapy. Such teeth and implants must be brought into the category with a secure prognosis by means of additional therapy such as endodontic, restorative, and surgical procedures. Teeth and implants with a hopeless pretherapeutic prognosis should be extracted/explanted during the initial phase of cause-related therapy (i.e., infection control). For example, teeth with vertical root fracture or unrestorable caries and implants with mobility or unrestorable malposition fall into the category of hopeless units. The primary goal of periodontal and peri-implant therapy should be to arrest disease progression. The latest consensus statement highlights that periodontitis can be successfully controlled and treated teeth can be retained for life. Nevertheless, for patients with uncontrolled contributing factors, the endpoints might not always be achievable, and low disease activity may be an acceptable therapeutic goal. Similarly, the management of peri-implantitis frequently requires surgical intervention following nonsurgical therapy due to incomplete treatment outcomes. Different surgical modalities can be effective and lead to significant improvement; however, achieving complete resolution of peri-implantitis is challenging, not always predictable, and can depend on multiple baseline factors. Therefore, this review aims at summarising available evidence on the rationale for incorporating systemic, lifestyle-related, clinical, and radiographic prognostic factors into treatment planning of patients diagnosed with periodontal and peri-implant diseases.

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.

Osteoradionecrosis incidence in pre-radiation teeth extractions: A prospective study

AIMS

To evaluate osteoradionecrosis (ORN) incidence in a cohort of patients undergoing tooth extraction (TE) before radiotherapy (RT) for head and neck cancers.

METHODS

The study protocol was approved by the Ethics Committee of Università Cattolica del Sacro Cuore (ID-2132) and registered at clinicaltrials.gov (ID: NCT04009161). TE was performed in case of signs of pericoronitis, periapical lesions, restorative impossibility, severe periodontitis. ORN was defined as exposed bone at an unhealed post-extraction socket in the absence of oncological recurrence. The RT plans were reviewed, and each post-extractive socket was contoured to calculate the received radiation dose.

RESULTS

In total, 156 patients with 610 TE were enrolled. The mean follow-up was 567 days. ORN was diagnosed in four patients (2.6% of patients and 0.7% of TE). Need for osteotomy and radiation dose at the extraction site were associated with ORN (OR for osteotomy: 21.9, 95% CI: 2.17-222.2, p = 0.009; OR for RT dose: 1.1, 95% CI: 1-1.15, p = 0.05).

CONCLUSIONS

TE appears to be a significant risk factor for ORN, particularly when osteotomy is required, and post-extraction sockets receive a high RT dosage. This study proposes a decision-making algorithm for TE and outlines a straightforward surgical protocol.

Implementation of a software application in staging and grading of periodontitis cases

OBJECTIVES

The purpose of this study was to assess the diagnostic accuracy and the inter-rater agreement among general dentists when staging and grading periodontitis cases with the aid of a software application (SA) developed by the Italian Society of Periodontology and Implantology.

MATERIALS AND METHODS

Ten general dentists were asked to independently assess 25 periodontitis cases using the SA. Accuracy was estimated using quadratic weighted kappa and examiners' percentage of agreement with a reference diagnosis provided by a gold standard examiner. Inter-rater agreement was evaluated using Fleiss kappa statistics.

RESULTS

The overall case definition agreed with the reference diagnosis in 53.6% of cases. The agreements for each general dentist's pairwise comparisons against the reference definition were at least substantial in 100% of cases for stage, in 70% of cases for grade and in none of the cases for extent. Fleiss kappa was 0.818, 0.608, and 0.632 for stage, extent, and grade, respectively. The study recognized possible reasons that could lead to decreased accuracy using the SA.

CONCLUSIONS

Supported by the SA, general dentists have reached substantial inter-rater agreement and highly accurate assignments of stage and grade. However, complete case definitions were correctly diagnosed in slightly over half of the cases.

A randomized double-blind clinical trial evaluating comparative plaque and gingival health associated with commercially available stannous fluoride-containing dentifrices as compared to a sodium fluoride control dentifrice

BACKGROUND

Gingivitis is a non-specific inflammatory lesion in response to the accumulation of oral biofilm and is a necessary precursor to periodontitis. Enhanced oral hygiene practices, including utilization of a dentifrice that could significantly improve plaque accumulation and gingival inflammation, is desirable to prevent and treat gingivitis and potentially prevent progression to periodontitis. This clinical study aimed to investigate the effect of a new stannous fluoride-containing dentifrice with 2.6% ethylenediamine tetra acetic acid (EDTA) as an anti-tartar agent to reduce plaque index and gingival index over a 3-month study period compared to other commercially-available fluoride-containing dentifrices.

METHODS

This double-blind, randomized controlled clinical study evaluated plaque, gingival inflammation, and sulcular bleeding in patients using one of five commercially available fluoride-containing dentifrices The dentifrices tested contained: 0.454% stannous fluoride and 2.6% EDTA (D1), 0.24% sodium fluoride (C), and 0.454% stannous fluoride (D2-D4). One hundred fifty subjects participated over a 3-month period. Co-primary endpoints were improvements in plaque index (PI) and modified gingival index (mGI) from baseline values. No professional cleaning was performed during the study period.

RESULTS

All subjects in the study demonstrated statistically significant improvements in all measures of oral hygiene over the 3-month study period. Subjects using dentifrice 1 (D1) showed statistically significantly greater reductions in PI, mGI, and modified sulcular bleeding index (mSBI) compared with all other commercially-available dentifrices tested (p < 0.00001).

CONCLUSIONS

A new dentifrice with 0.454% stannous fluoride and 2.6% EDTA demonstrated significant improvements in clinical parameters associated with gingivitis compared to other sodium and stannous fluoride containing dentifrices.

HIF-1α drives the transcription of NOG to inhibit osteogenic differentiation of periodontal ligament stem cells in response to hypoxia

Osteogenic differentiation of periodontal ligament stem cells (PDLSCs) is limited in hypoxia, and HIF-1α is key to the response to hypoxia. However, its mechanisms remain largely unknown. This study discovered an osteogenesis-related gene sensitive to hypoxia in PDLSCs, and investigated the molecular mechanisms between HIF-1α and the gene. NOG, a gene that negatively regulates osteogenesis, was discovered by RNA-seq. Under normoxic conditions, HIF-1α overexpression led to enhanced expression of NOG/Noggin and inhibited the expression of osteogenesis-related genes, while inhibition of HIF-1α reversed this effect. The expression of HIF-1α, NOG/Noggin and the osteogenesis-related genes were detected by qRT-PCR or Western blot. Mechanistically, we verified that HIF-1α binds to the hypoxia response element (-1505 to -1502) in the promotor of NOG to enhance secretion of Noggin by chromatin immunoprecipitation and a dual-luciferase reporter assay. IHC staining findings in an animal model verified that Noggin-associated osteogenic differentiation was inhibited in hypoxia. NOG displayed a concordant relationship with HIF-1α, and secreted more with increasing of HIF-1α. Hypoxia stabilized HIF-1α, which bound to the HRE (-1505 to -1502) of the NOG promotor to enhance NOG transcription resulted in inhibiting osteogenic differentiation of PDLSCs. This study offers a promising therapy for periodontitis.

Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline

BACKGROUND

The recently published clinical practice guideline (CPG) for the treatment of periodontitis in stages I-III provided evidence-based recommendations for the treatment of periodontitis patients, defined according to the 2018 classification. Stage IV periodontitis shares the severity and complexity characteristics of stage III periodontitis, but includes the anatomical and functional sequelae of tooth and periodontal attachment loss (tooth flaring and drifting, bite collapse, etc.), which require additional interventions following completion of active periodontal therapy.

AIM

To develop an S3 Level CPG for the treatment of stage IV periodontitis, focusing on the implementation of inter-disciplinary treatment approaches required to treat/rehabilitate patients following associated sequelae and tooth loss.

MATERIALS AND METHODS

This S3 Level CPG was developed by the European Federation of Periodontology (EFP), following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and a structured consensus process with leading experts and a broad base of stakeholders.

RESULTS

The S3 Level CPG for the treatment of stage IV periodontitis culminated in recommendations for different interventions, including orthodontic tooth movement, tooth splinting, occlusal adjustment, tooth- or implant-supported fixed or removable dental prostheses and supportive periodontal care. Prior to treatment planning, it is critically important to undertake a definitive and comprehensive diagnosis and case evaluation, obtain relevant patient information, and engage in frequent re-evaluations during and after treatment. The periodontal component of therapy should follow the CPG for the treatment of periodontitis in stages I-III.

CONCLUSIONS

The present S3 Level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat patients with stage IV periodontitis and to maintain a healthy dentition over lifetime, according to the available evidence at the time of publication.

Diagnostic accuracy of active matrix metalloproteinase-8 point-of-care test for the discrimination of periodontal health status: Comparison of saliva and oral rinse samples

BACKGROUND AND OBJECTIVES

Assessment of biomarkers, specifically active matrix metalloproteinase-8 (aMMP-8), in saliva/oral rinses is a promising diagnostic approach for periodontal health and disease. Different oral fluids have specific advantages and limitations. This study investigates the effect of sampling different fluids on the accuracy of an aMMP-8 point of care test (POCT).

METHODS

Unstimulated whole saliva, a first, and a second oral rinse were sequentially taken from 95 consecutive adults. aMMP-8 was quantitatively determined with a lateral flow immunoassay (index test). A full-mouth periodontal examination was used to establish a diagnosis according to the 2017 World Workshop classification of periodontal diseases (reference standard). Diagnostic measures of the area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity were assessed and compared.

RESULTS

In all oral fluid samples, periodontitis patients (N = 61) had significantly elevated aMMP-8 levels and increased test positivity rates compared with subjects with periodontal health or gingivitis (N = 34). The intra-individual comparison showed that aMMP-8 levels were significantly higher in 1st oral rinse compared with other samples (1^st oral rinse > saliva = 2^nd oral rinse, p = .007). The aMMP-8 test using 1st oral rinse exhibited the best accuracy for detecting periodontitis with a sensitivity of 80.3%, a specificity of 67.8% and an AUROC of 0.740.

CONCLUSIONS

A 30-second oral rinse with water omitting the prerinse provided the best accuracy to discriminate periodontal health and disease with an aMMP-8 POCT. This regimen seems promising for further studies in large representative populations to verify the current findings.

Intra- and inter-examiner reliability in classifying periodontitis according to the 2018 classification of periodontal diseases

Aim

To evaluate the inter‐examiner reliability in classifying periodontitis using the 2018 classification of periodontal diseases, when used by postgraduate students, academics, and specialist clinicians trained in European Federation of Periodontology (EFP) and American Academy of Periodontology (AAP) postgraduate‐accredited programmes.

Materials and Methods

An online survey including five patients with periodontitis was sent twice to seven specialists in periodontology to provide the staging and grading characteristics. After agreeing on a “gold‐standard” classification, the same questionnaire was sent to 16 EFP and 73 AAP postgraduate programmes, to be answered by their faculty, graduates, and students. The responses were compared with the gold‐standard classification, and the inter‐examiner agreement was calculated.

Results

One‐hundred and seventy‐four participants completed the survey. The inter‐examiner agreement resulted in 68.7% in assigning the stage, 82.4% in assigning the grade, and 75.5% in assigning the extent. The academic position and the experience of the participants did not have any significant influence on classifying periodontitis as the gold standard.

Conclusions

The use of the 2018 periodontitis classification resulted in high inter‐examiner reliability when used by a specialist group of clinicians, postgraduate students, and academicians, irrespective of their current position and experience. Given the low response rate and potential selection bias, results pertaining to the use of this system in classifying periodontitis should be interpreted with caution.

Assessment of masticatory function in the differential diagnosis of stage IV periodontitis: A pilot diagnostic accuracy study

BACKGROUND

After diagnosis of periodontitis is made, detection of stage IV cases is critical for appropriate management that may call for interdisciplinary care. This study aims to identify and assess the accuracy of a simple screening approach for practice and surveillance of stage IV periodontitis.

METHODS

Masticatory function assessments by both validated self-reported masticatory dysfunction questionnaire and dual-color chewing gum mixing ability test (index test) were conducted in 214 consecutive patients, followed by a full-mouth periodontal examination. Periodontal diagnosis was based on the 2017 World Workshop classification of periodontal diseases (reference standard). Multivariate logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were performed.

RESULTS

Overall, the individual patient-reported masticatory dysfunction questions showed low to moderate accuracy for predicting Stage IV periodontitis. The objective measures of masticatory function by calculating the variance of hue from the chewing gum test performed better with an AUROC of 0.840. A diagnostic approach based on age, self-report of altered food type intake, and chewing gum test result exhibited excellent performance for predicting Stage IV periodontitis (sensitivity: 89.7%; specificity:76.3%; AUROC:0.912).

CONCLUSIONS

Once the presence of periodontitis has been established, a simple diagnostic approach that does not require specialized workforce, complex or lengthy assessment allows identification of Stage IV periodontitis patients. This is important as these patients require specific case work up and interdisciplinary care pathways. Additional studies are required to validate the findings in multiple populations. This article is protected by copyright. All rights reserved.

Food Intake, Masticatory Function, Tooth Mobility, Loss of Posterior Support and Diminished Quality of Life Are Associated with More Advanced Periodontitis Stage Diagnosis

AIMS

To describe periodontal and functional characteristics of subjects diagnosed with different stages of periodontitis and to associate measures of masticatory function and quality of life with periodontitis stage.

METHODS

This was a cross-sectional study on a convenience sample of 214 subjects with periodontitis seeking oral care in a hospital setting. They received a full mouth intraoral examination including dental and periodontal charting by a single calibrated examiner who also established the periodontitis stage diagnosis. Subjects were assessed using the OHIP-14, a validated masticatory dysfunction questionnaire and a quantitative test based on the ability to mix a dual color chewing gum. Mixing was quantified based on variance of hue (VOH) with a colorimetric software. Descriptive, univariate and multivariate analyses were performed.

RESULTS

Subjects with stage IV periodontitis reported greater impairment of oral health related quality of life, reduced food intake or altered food type intake attributed to difficulties in chewing, objective measures of masticatory dysfunction, tooth loss as well as more advanced periodontal breakdown compared with subjects with stage I-III diagnosis. Quantitative assessment of masticatory function was associated in a multivariate analysis with: i) loss of functional tooth units in the premolar/molar region, presence of hypermobile teeth and severity of periodontal attachment loss; and ii) age, body mass index and periodontitis stage IV and grade C diagnosis.

CONCLUSIONS

Stage IV periodontitis subjects are characterized by a specific set of signs and symptoms of advanced periodontal breakdown and functional impairment which impact on quality of life and masticatory function/food intake choices. Stage IV periodontitis captures a clinical entity with distinct features and treatment needs. This article is protected by copyright. All rights reserved.

Prognostic performance of the 2017 World Workshop Classification on staging and grading of periodontitis compared with the British Society of Periodontology's implementation

BACKGROUND

The British Society of Periodontology (BSP) implemented a simplified version of the 2017 World Workshop Classification (WWC) on staging and grading of periodontitis, for use in UK clinical practice. The aim of this study was to assess the long-term (>10 years) prognostic capability of BSP's implementation (BSP-i) compared with the 2017 WWC, using periodontal-related tooth loss (TLP) as a disease outcome.

METHODS

Data on medical history, smoking status, and clinical periodontal parameters were retrieved from 270 patients who received non-surgical and surgical periodontal therapy from 1966 to 2007. Each patient received a baseline diagnosis according to the 2017 WWC and the BSP-i guidelines for implementation. Univariate multilevel Cox regression frailty models were performed to analyze the association between variables with TLP. A post-hoc comparison with Bonferroni correction was performed to analyze interclass comparisons. The prognostic performance of both systems was analyzed using Harrell C index.

RESULTS

The prognostic performance of both systems was very similar (0.922 for the 2017 WWC and 0.925 for the BSP-i). The singular prognostic performance of BSP stage was slightly higher than that of 2017 WWC stage (0.9212 versus 0.9188), while the 2017 WWC grade showed a slightly better performance than BSP grade (0.9175 versus 0.9155). BSP-i's extent performed better than the 2017 WWC extent (0.9203 versus 0.9098); however, in the 2017 WWC extent, the class "localized" was associated with a better prognosis than "generalized."

CONCLUSION

The overall prognostic performance of the two systems was excellent, with both systems having a Harrell C index score of >0.92.

Diagnostic accuracy of a point-of-care aMMP-8 test in the discrimination of periodontal health and disease

Aim

To assess the diagnostic utility of an oral rinse active matrix metalloproteinase‐8 (aMMP‐8) point‐of‐care test (POCT) for differentiating periodontal health, gingivitis, as well as different stages and grades of periodontitis.

Materials & Methods

The aMMP‐8 index test was undertaken in 408 consecutive adults, followed by a full‐mouth periodontal examination. The reference standard was the 2017 World Workshop classification of periodontal diseases. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUROC) were assessed.

Results

68.6% of the participants were diagnosed with periodontitis, including Stages I (15.9%), II (15.9%), III (29.7%) and IV (7.1%). A positive aMMP‐8 POCT was associated with periodontitis after adjusting for age, gender, tobacco smoking and systemic diseases, while it was unable to differentiate among the stages/grades of periodontitis and between gingivitis/periodontal health. This test showed a sensitivity of 33.2% and a specificity of 93.0% for detecting periodontitis (threshold level >10 ng/ml). The levels of aMMP‐8 adjusted by the number of teeth present (aMMP‐8/NTP) performed better for periodontitis (sensitivity: 67.1%; specificity: 68.8%). Notably, aMMP‐8/NTP were strongly predictive for Stage IV periodontitis (threshold level =0.4312 ng/ml) (sensitivity: 89.7%; specificity: 73.6%; and AUROC: 0.856). The test performance greatly improved in combination with age and smoking, with a sensitivity of 82.5%, a specificity of 84.4%, and an AUROC of 0.883.

Conclusion

This aMMP‐8 POCT is able to detect periodontitis with better specificity than sensitivity across the spectrum of its severity. This test may be useful for periodontal screening in conjunction with subject characteristics and/or other sensitive screening tools. Further validation studies are needed.

Maintenance visit regularity has a different impact on periodontitis-related tooth loss depending on patient staging and grading

AIM

To assess whether maintenance variables have a differential effect on tooth loss due to periodontitis (TLP) based on staging and grading.

MATERIALS AND METHODS

Patients treated for periodontitis for a minimum of ≥10 years follow-up were included and categorized according to their stage and grade at baseline. Impact of number, regularity, and pattern of supportive periodontal therapy visits (SPT) on TLP was explored by dividing teeth into test (5 year time periods prior to TLP events) and control groups (random 5 year periods without tooth loss).

RESULTS

The regularity of maintenance visits, but not the overall quantity, had a significant impact on risk of TLP and showed higher importance as staging and grading increased (larger impact for stages III/IV and grade C). The minimum threshold of visits below which the risk of TLP was equivalent to that of the control group was one visit every 7.4 months for stages I-II, 6.7 months for stage III-IV, 7.2 months for grade B and 6.7 months for grade C. This frequency should be increased for former and current smokers, diabetics and elderly patients. Stage III and IV patients who skip more than 1 year of maintenance in a 5 year period have an increased risk of TLP (OR = 2.55) compared to those only miss 1 year. A similar trend was noted for grade C patients, but not for stages I/II or grades A/B.

CONCLUSIONS

Lack of SPT regularity and missing multiple years of maintenance had a larger influence on risk of TLP for higher-level staging and grading.

The staging and grading system in defining periodontitis cases: consistency and accuracy amongst periodontal experts, general dentists and undergraduate students

AIM

The objective of this study was to evaluate consistency and accuracy of the periodontitis staging and grading classification system.

METHODS

Thirty participants (10 periodontal experts, 10 general dentists and 10 undergraduate students) and a gold-standard examiner were asked to classify 25 fully documented periodontitis cases twice. Fleiss kappa was used to estimate consistency across examiners. Intraclass correlation coefficient (ICC) was used to calculate consistency across time. Quadratic weighted kappa and percentage of complete agreement versus gold standard were computed to assess accuracy.

RESULTS

Fleiss kappa for stage, extent and grade were 0.48, 0.37 and 0.45 respectively. The highest ICC was provided by students for stage (0.91), whereas the lowest ICC by general dentists for extent (0.79). Pairwise comparisons against gold standard showed mean value of kappa >0.81 for stage and >0.41 for grade and extent. Agreement with the gold standard for all three components of the case definition was achieved in 47.2% of cases. The study identified specific factors associated with lower consistency and accuracy.

CONCLUSIONS

Diagnosis was highly consistent across time and moderately between examiners. Accuracy was almost perfect for stage and moderate for grade and extent. Additional efforts are required to improve training of general dentists.