1. Molar longevity

This study aimed to identify risk factors for loss of molars during supportive periodontal therapy (SPT). A total of 136 subjects with 1,015 molars at baseline were examined retrospectively. Fifty molars were extracted during active periodontal therapy (APT) and 154 molars over the average SPT period of 13.2 +/- 2.8 years. Furcation involvement (FI), baseline bone loss > 60% (BL), residual mean probing pocket depth (PPD) and endodontic treatment were identified as relevant tooth-related factors for loss of molars during SPT. However, mean survival time for molars with FI or BL were 11.8 and 14.4 years, respectively. Among the patient data age, female gender, smoking and diabetes mellitus were significant predictors for loss of molars. Overall, periodontal therapy results in a good prognosis of molars. FI, progressive BL, endodontic treatment, residual PPD, age, female gender, smoking, and diabetes mellitus strongly influence the prognosis for molars after APT.

Dannewitz B et al. Loss of molars in periodontally treated patients: results 10 years and more after active periodontal therapy. J Clin Periodontol 2016 43: 53-62.

Q Which of the following patients are more likely to lose molars?
A Young males who are non-smokers
B Older males who smoke but are otherwise healthy
C Older females who smoke and have diabetes
D Patients of either gender who are non-smokers and who have diabetes

2. The heart of the matter

It has been postulated that periodontitis (PD) could be causally related to the risk for cardiovascular disease, a hypothesis tested in the Periodontitis and Its Relation to Coronary Artery Disease study. A total of 805 patients (<75 years of age) with a first myocardial infarction (MI) and 805 age- (mean 62+/-8), sex- (male 81%), and area-matched controls without MI underwent standardised dental examination including panoramic x-ray. The periodontal status was defined as healthy (>80% remaining bone) or as mild-moderate (from 79% to 66%) or severe (<66%). PD was more common (43%) in patients than in controls (33%). There was an increased risk for MI among those with PD, which remained significant after adjusting for variables (smoking habits, diabetes mellitus, years of education, and marital status). In this large case-control study of PD, verified by radiographic bone loss and with a careful consideration of potential confounders, the risk of a first MI was significantly increased in patients with PD even after adjustment for confounding factors.

Ryden L et al. Periodontitis increases the risk of a first myocardial infarction: a report from the PAROKRANK study. Circulation 2016 133: 576-583.

Q The risk of a first MI was significantly increased:
A In patients with periodontitis
B In patients without periodontitis
C If bone levels were greater than 80% remaining
D None of the above

3. Under pressure

The purpose of this prospective cohort study was to investigate whether periodontal disease was related to prehypertension/hypertension in Japanese university students. Students (n = 2,588) underwent health examinations before entering university and before graduation, being assessed for the percentage of bleeding on probing (BOP), community periodontal index (CPI) scores and change in blood pressure status. At the re-examination, the numbers of participants with prehypertension (systolic blood pressure 120-139mm Hg or diastolic blood pressure 80-89mm Hg) and hypertension (>140/90mm Hg) were 882 (34.1%) and 109 (4.2%), respectively. The risk of hypertension was significantly associated with males, no habitual physical activity at baseline and periodontal disease defined as the presence of both probing pocket depth (PPD) > 4mm and BOP > 30% at baseline in participants with prehypertension at baseline. Conversely, the risk of prehypertension was not associated with presence of periodontal disease. Overall, there was a significant association between the presence of periodontal disease and hypertension.

Kawabata Y et al. Relationship between prehypertension/hypertension and periodontal disease: a prospective cohort study. Am J Hypertension 2016 29: 388-396.

Q Which of the following was true in this study?
A 34.1% of the participants were male
B The risk of periodontal disease was significantly associated with no habitual physical activity at baseline
C There was a significant association between the presence of periodontal disease and hypertension
D Periodontal disease was defined as the presence of probing pocket depth (PPD) > 4mm at baseline

4. Probing the risk

The influence of potential risk factors, primarily smoking and a prior history of periodontitis, on the severity of peri-implantitis was assessed in patients referred for treatment of peri-implantitis. Among 98 patients referred for treatment of peri-implantitis, 34 fulfilled the inclusion criteria: one or several implants with peri-implant marginal bone loss >2 mm concomitant with bleeding and/or pus on probing. Information about health status, smoking habits, reason for tooth loss, and performed implant treatment were obtained from the patient charts and interviews. A detailed extra- and intraoral examination was performed, including intraoral radiographs of all implants. Smoking and a prior history of periodontitis were significant risk factors for increased severity of peri-implantitis. The concomitant presence of these two risk factors did not further increase the severity of peri-implantitis, as compared to either of these two risk factors alone. Poor marginal fit of the suprastructure and extensive gingival imitations on implant-supported fixed full prostheses may also be potential risk factors.

Saaby M et al. Factors influencing severity of peri-implantitis. Clin Oral Implants Res 2016 27: 7-12.

Q The risk of peri-implantitis is:
A Solely due to poor marginal fit of the suprastructure
B Doubled in smokers and those with a prior history of periodontitis
C Greater in patients who smoke or who have a prior history of periodontitis
D Only manifest in patients who attend with pus on probing