Regenerative periodontal surgical procedures are an important component in the treatment of advanced periodontitis. They aim to improve the long‐term prognosis of teeth that are periodontally compromised by the presence of intrabony and/or furcation defects, resulting biologically in formation of root cementum, periodontal ligament, and alveolar bone and evidenced clinically by reduction of deep pockets to maintainable probing depths and/or improvements of vertical and horizontal furcation depth. Over the last 25 years, substantial clinical evidence has been accumulated to support the value of regenerative procedures in periodontally compromised dentitions. However, treatment success requires close attention to certain factors on the level of the patient, the tooth/defect, and the operator. Ignoring these factors in case selection, treatment planning, and treatment execution will increase the risk of complications that may jeopardize clinical success and may even be considered as treatment errors. Based on the currently available evidence from clinical practice guidelines, treatment algorithms, and on expert opinion, the present article provides an overview on the main factors, which influence the outcomes of regenerative periodontal surgery and gives recommendations on how to prevent complications and treatment errors.

In this review, typical clinical complications involving periodontal tissues are illustrated that can be encountered in conjunction with orthodontic therapy (OT). Special considerations are given for various clinical scenarios, such as the patient presenting in periodontal health, with periodontitis, or with mucogingival conditions. While some of the complications are seen as common side effects of OT, other, more severe, problems that could have been avoided may be viewed as treatment errors. Recommendations are made on how to prevent these complications, based on the currently available evidence, on clinical practice guidelines, and on expert opinion. In conclusion, while there are several areas in which OT can have unwanted adverse effects on periodontal/mucogingival conditions, there is also great potential for synergies, offering opportunities for close cooperation between the two specialties (periodontics and orthodontics) for the benefit of patients affected by tooth malpositioning and/or periodontal or mucogingival problems.

There is a paucity of data for the effectiveness of reconstructive procedures in the treatment of peri-implantitis. The objective of this study was to compare reconstruction of peri-implant osseous defects with open flap debridement (OFD) plus porous titanium granules (PTGs) compared with OFD alone. Sixty-three patients (36 female, 27 male; mean age 58.4 y [SD 12.3]), contributing one circumferential peri-implant intraosseous defect, were included in a multinational, multicenter randomized trial using a parallel-group design. After OFD and surface decontamination using titanium brushes and hydrogen peroxide, 33 defects received PTGs. The implants were not submerged. All patients received adjunctive perioperative systemic antibiotics. The primary outcome variable (defect fill) was assessed on digitalized radiographs. Clinical measurements of probing depth (PPD), bleeding on probing (BoP), suppuration, and plaque were taken by blinded examiners. After 12 mo, the test group (OFD plus PTG) showed a mean radiographic defect fill (mesial/distal) of 3.6/3.6 mm compared with 1.1/1.0 in the control group (OFD). Differences were statistically significant in favor of the test group ( P < 0.0001). The OFD plus PTG group showed a mean reduction in PPD of 2.8 mm compared with 2.6 mm in the OFD group. BoP was reduced from 89.4% to 33.3% and from 85.8% to 40.4% for the test and control groups, respectively. There was no significant difference in complete resolution of peri-implantitis (PPD ≤4 mm and no BoP at six implant sites and no further bone loss), because this finding was accomplished at 30% of implants in the test group and 23% of implants in the control group. Reconstructive surgery using PTGs resulted in significantly enhanced radiographic defect fill compared with OFD. However, limitations in the lack of ability to discern biomaterial from osseous tissue could not be verified to determine new bone formation. Similar improvements according to clinical measures were obtained after both surgical treatment modalities (ClinicalTrials.gov NCT02406001).

Objective: This retrospective surveillance study aimed to follow periodontitis‐associated bacterial profiles and to identify time‐dependent changes in antibiotic susceptibility patterns.Materials and Methods: From 2008 to 2015, bacterial specimen from deep periodontal pockets were collected from a total of 7804 German adults diagnosed with periodontitis. Presence of selected bacteria was confirmed by anaerobic culture and nucleic acid amplification. Antimicrobial susceptibility of clinical isolates was tested by disc diffusion with antibiotics used for the treatment of periodontitis and oral infections. The prevalences of periodontal pathogens were calculated and temporal evolution of antimicrobial susceptibility towards amoxicillin, amoxicillin/clavulanic acid, metronidazole, doxycycline, clindamycin, azithromycin, ciprofloxacin and ampicillin was analysed with logistic regression.Results: The prevalence of patients harbouring bacteria was 95.9% Fusobacterium nucleatum, 88.0% Tannerella forsythia, 76.4% Treponema denticola, 76.5%, Campylobacter rectus, 76.0% Eikenella corrodens, 75.0% Capnocytophaga spp., 68.2% Porphyromonas gingivalis, 57.7% Peptostreptococcus micros, 43.1% Prevotella intermedia, 30.4% Eubacterium nodatum and 21.5% Aggregatibacter actinomycetemcomitans. In 63.5% of patients, one or more isolates were not susceptible to at least one of the antibiotics tested. The data further revealed a trend towards decreasing susceptibility profiles (p < 0.05) with antibiotic non‐susceptibilities in 37% of patients in 2008 and in 70% in 2015.Conclusions: The present study confirmed a high prevalence of periodontal pathogens in the subgingival microbiota of German periodontitis patients. The data revealed an incremental increase in isolates displaying resistance to some antibiotics but no relevant change in susceptibility to amoxicillin and metronidazole.

Background: This study compared 6‐month and 3‐year outcomes for root coverage (RC) by coronally advanced flap (CAF) procedures in localized gingival recessions.Methods: Two centers, that had participated in a 6‐month multinational multicenter randomized clinical trial (RCT), followed up 18 patients with 36 Miller Class I and II defects that had been treated in a split‐mouth design with CAF procedures or CAF + xenogeneic collagen matrix (CMX). Percentage of RC, complete root coverage (CRC), width, and thickness of keratinized tissue were assessed by the same masked examiners as after the 6‐month RCT.Results: There was a high correlation between 6‐month and 3‐year RC outcomes for both CAF procedures. Mean RC after CAF + CMX amounted to 89.9% after 6 months and 91.7% after 3 years (Pearson’s correlation: 0.91). Corresponding values for CAF were 83.7% versus 82.8% (Pearson’s correlation: 0.94). Likewise, CRC was stable with 61%/61% for CAF + CMX and 39%/39% for CAF after 6 months/3 years, respectively.Conclusions: In this 3‐year follow‐up of a subgroup of patients from a previous 6‐month RCT, there was a high correlation between the results for RC after 6 months and 3 years, indicating their stability. These data suggest that 6‐month outcomes may be useful to predict long‐term outcomes in CAF procedures with or without additional use of CMX.

Aim: To compare the outcomes after early (4 weeks post surgery) or late (6 months post surgery) orthodontic therapy (OT) following regenerative surgery of intra‐bony defects (IDs).Materials and methods: In a multi‐center, parallel‐group, randomized clinical trial, 43 patients with stage IV periodontitis were randomized to receive either early (n = 23) or late OT (n = 20) following regenerative surgery of IDs. Primary outcome was change in clinical attachment level (CAL) in one target ID at 12 months after surgery. Secondary outcomes were changes of probing pocket depth (PPD), bleeding on probing (BOP), and frequency of pocket closure.Results: No statistically significant differences between groups could be observed for CAL gain (5.4 mm [±2.1 mm] for early; 4.5 mm [±1.7 mm] for late OT). PPD was reduced by 4.2 mm (±1.9 mm) in the early group and by 3.9 mm (±1.5 mm) in the late group (p > .05). Pocket closure (PPD ≤ 4 mm) was obtained in 91% of defects in early compared to 85% in late OT.Conclusion: In the inter‐disciplinary treatment of periodontitis stage IV, OT can be initiated already 4 weeks after regenerative surgery of IDs with favourable results, thus reducing the overall treatment time.