Periodontal risk score: Initiation and model validation for 6,762 teeth.

BACKGROUND: Tooth-level prognostic systems are valuable tools for treatment planning and risk assessment of periodontally involved teeth. Recently the Miller-McEntire prognosis index was found to outperform comparable systems. However, it had some limitations. The present study aimed to develop and evaluate the prognostic performance of a modified version that addresses most limitations of the previous model called the periodontal risk score (PRS). METHODS: Data were retrieved retrospectively from patients who received surgical and non-surgical periodontal treatment at a university setting. Data on medical history and smoking status at baseline and the last maintenance visit were collected. Both univariate and multivariate Cox proportional hazard regression models were used to analyze the prognostic capability for predicting tooth loss due to periodontitis (TLP) risk. RESULTS: A total of 6762 teeth (281 patients) were followed up for a mean period of 22.6 ± 6.34 (10-47.6y) years. The PRS was successfully able to stratify the risk of TLP at baseline when the three different classes of association were compared for anterior and/or posterior tooth loss. After controlling for maintenance, age, and sex, the index showed an excellent predictive capacity for TLP with a Harrell C-index of 0.947. CONCLUSIONS: The periodontal risk score (PRS) displayed excellent predictive capability for anterior as well as posterior tooth loss due to periodontitis. This system was able to predict long-term tooth loss with a very high accuracy  in a population treated mainly by dental students and periodontics residents. The use of this/similar prognosis system is advisable as a means to establish tooth prognosis.

Is the degree of physiological bone remodeling a predictive factor for peri-implantitis?

BACKGROUND: The amount of initial physiological bone remodeling (IPBR) after implant placement varies and the ways it may play a role in peri-implantitis development remains unknown. The aim of this retrospective study was to investigate the association between the amount of IPBR during the first year of implant placement and incidence of peri-implantitis as well as the pattern of progressive bone loss. METHODS: Clinical and radiographic documentation of implants at the time of implant placement (T0), 1 year ± 6 months after crown placement (T1), and at a ≥2-year follow-up from implant placement (T2) were retrospectively collected. IPBR was defined as the bone loss occurring from implant placement to the end of the bone remodeling (T1). Cases were grouped into those diagnosed with (test) or without peri-implantitis (PIm) (control). Linear regression model under generalized estimation equation approach was estimated to assess correlation between marginal bone loss (MBL) rates in both periods (T1-T0) and (T2-T1). Receiver operating characteristics curve was estimated to explore an optimal cut-off point of T1-T0 MBL to discriminate between PIm and no-PIm implants. RESULTS: A total of 45 patients receiving 57 implants without PIm and 40 with PIm were included. There were no associations between PIm and IPBR (p > 0.05), nor between BML of (T2-T1) and (T1-T0). However, arch and total follow-up showed significant influence on the probability of PIm. Splinted implants showed an MBL rate of 0.60-mm/year higher than non-splinted implants (p < 0.001) from T1 to T2. CONCLUSION: No statistically significant association was found between IPBR and incidence of peri-implantitis.

Impact of the periodontal phenotype in premolar and molar sites on bone loss following full-thickness mucoperiosteal flap: A 1-year prospective clinical trial.

BACKGROUND: Full-thickness mucoperiosteal flap (FTF) elevation could potentially affect the periodontium of the involved teeth; it is not clear if the periodontal phenotype of teeth involved in a FTF may influence these changes. The aim of this study was to evaluate the impact of FTF on teeth periodontium, as well as assessing the impact of periodontal phenotype on bone remodeling. METHODS: In this single arm prospective clinical trial, 26 subjects and a total of 52 adjacent teeth were included. Patients receiving implant surgery in the posterior area, at the time of implant site preparation, an FTF was extended one tooth mesial and distal to the planned site, and the flap was elevated both facially and lingually. Vertical and horizontal bone linear changes were measured on both adjacent teeth, using superimposed cone-beam computerized tomography (CBCT) images taken prior to implant placement (T0) and at 12 months (T1). Baseline digital scans of models and DICOM files were superimposed to assess the periodontal phenotype. RESULTS: Vertical bone changes from T0 to T1 were statistically significant (P = 0.013), with changes were significantly higher at the mesial (-0.31 ± 0.30 mm) and facial (P < 0.05) sites. Horizontal dimensional changes 5 mm subcrestally were similar among different locations (P = 0.086) and the bone width loss was higher closest to the crest (P = 0.001). No correlation was found between soft tissue thickness and bone changes. However, bone thickness at baseline appears to influence the extent of horizontal bone remodeling. Overall, the magnitude of bone loss either vertically or horizontally was clinically insignificant (≤0.4 mm). A preventive effect against bone loss maybe expected with bone thickness > 2 mm. CONCLUSION(S): Marginal bone changes in maxillary and mandibular posterior teeth following FTF at 12 months are very minimal, and mainly influenced by bone rather than soft tissue thickness. Overall, FTF does not seem to have deleterious effects on adjacent teeth periodontium.

Long term comparison of the prognostic performance of PerioRisk, periodontal risk assessment, periodontal risk calculator, and staging and grading systems.

BACKGROUND: Clinicians predominantly use personal judgment for risk assessment. Periodontal risk assessment tools (PRATs) provide an effective and logical system to stratify patients based on their individual treatment needs. This retrospective longitudinal study aimed to validate the association of different risk categories of four PRATs (Staging and grading; Periodontal Risk Assessment (PRA); Periodontal Risk Calculator; and PerioRisk) with periodontal related tooth loss (TLP), and to compare their prognostic performance. METHODS: Data on medical history, smoking status, and clinical periodontal parameters were retrieved from patients who received surgical and non-surgical periodontal treatment. A comparison of the rate of TLP and non-periodontal related tooth loss (TLO) within the risk tool classes were performed by means of Kruskal-Wallis test followed by post-hoc comparison with the Bonferroni test. Both univariate and multivariate Cox Proportional hazard regression models were built to analyze the prognostic significance for each single risk assessment tool class on TLP. RESULTS: A total of 167 patients with 4321 teeth followed up for a mean period of 26 years were assigned to four PRATs. PerioRisk class 5 had a hazard ratio of 18.43, Stage 4 had a hazard ratio of 7.99, and PRA class 3 had a hazard ratio of 6.13 compared with class/stage I. With respect to prognostic performance, PerioRisk tool demonstrated the best discrimination and model fit followed by PRA. CONCLUSION: All PRATs displayed very good predictive capability of TLP. PerioRisk showed the best discrimination and model fit, followed by PRA.

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.

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.