Norbert Cionca

The epidemiology of peri‐implantitis

AIM To review the literature on the prevalence and incidence of peri-implantitis. METHODS Out of 322 potentially relevant publications we identified 29 articles concerning 23 studies, with information on the presence of signs of peri-implantitis in populations of at least 20 cases. RESULTS AND CONCLUSIONS All studies provided data from convenience samples, typically from patients who were treated in a clinical center during a certain period, and most data were cross-sectional or collected retrospectively. Based on the reviewed papers one may state that the prevalence of peri-implantitis seems to be in the order of 10% implants and 20% patients during 5-10 years after implant placement but the individual reported figures are rather variable, not easily comparable and not suitable for meta-analysis. Factors that should be considered to affect prevalence figures are the disease definition, the differential diagnosis, the chosen thresholds for probing depths and bone loss, differences in treatment methods and aftercare of patients, and dissimilarities in the composition of study populations. Smoking and a history of periodontitis have been associated with a higher prevalence of peri-implantitis.

Microbiologic testing and outcomes of full-mouth scaling and root planing with or without amoxicillin/metronidazole in chronic periodontitis.

BACKGROUND It has been suggested that use of systemic antibiotics should be limited to patients with specific microbiologic profiles. The main purpose of the present analysis was to study whether microbiologic testing before therapy was of value in predicting which patients would specifically benefit from adjunctive amoxicillin and metronidazole, given in the context of full-mouth scaling and root planing (SRP) within 48 hours. METHODS This was a 6-month, single-center, double-masked, placebo-controlled, randomized longitudinal study. Fifty-one patients received full-mouth periodontal debridement, performed within 48 hours; then, 25 subjects received metronidazole, 500 mg, and amoxicillin, 375 mg, three times a day for 7 days, and 26 received a placebo (control group). Pooled microbiologic samples were taken from the deepest pocket at baseline in each quadrant before and 6 months after treatment. Six periodontal pathogens were quantified by real-time polymerase chain reaction. RESULTS Forty-seven patients were followed for 6 months. After treatment, test subjects had a substantially lower mean number of persisting sites with probing depth >4 mm and bleeding on probing than did control subjects (0.4 versus 3.0; P = 0.005; month 6). Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) could not be detected in the antibiotic group after treatment. However, in the placebo group, three of six subjects positive for A. actinomycetemcomitans continued to be positive. Lower frequencies were also noted in the test group for Porphyromonas gingivalis (P = 0.013) and Tannerella forsythia (previously T. forsythensis) (P = 0.007). However, even subjects testing negative for A. actinomycetemcomitans at baseline had a significantly better primary clinical outcome if they received the active drugs. The presence of six putative periodontal pathogens (A. actinomycetemcomitans, Fusobacterium nucleatum spp., P. gingivalis, Prevotella intermedia, Treponema denticola, and T. forsythia) quantified prior to therapy was not correlated with the outcome of full-mouth SRP with or without amoxicillin and metronidazole. CONCLUSION Excellent clinical results in the antibiotics group were obtained regardless of the presence or absence of six classic periodontal periopathogens prior to treatment.

Effect of Photodynamic Therapy, Diode Laser, and Deep Scaling on Cytokine and Acute-Phase Protein Levels in Gingival Crevicular Fluid of Residual Periodontal Pockets

BACKGROUND There is an ongoing controversy on the benefits of treatment protocols, including dental lasers and photodynamic therapy (PDT). The purpose of this study is to compare the local biologic effects of PDT, diode soft laser (DSL) therapy, and conventional deep scaling and root planing (SRP) in residual pockets. METHODS Thirty-two individuals were included based on a history of previous treatment for periodontitis and the persistence of sites with probing depths >4 mm and bleeding on probing. Residual pockets were debrided with an ultrasonic device and then randomly assigned either to PDT, DSL, or SRP. Gingival crevicular fluid was collected before treatment, after 14 days, and at 2 and 6 months. Levels of 13 cytokines and nine acute-phase proteins were measured using a bead-based multiplexing analysis system. RESULTS Treatment with PDT, DSL, or SRP led to significant changes in several cytokines and acute-phase proteins: Compared with baseline, levels of interleukin-17, basic fibroblast growth factor, granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor, and macrophage inflammatory protein 1-α were lower 14 days and 2 months after treatment. Except for granulocyte colony-stimulating factor, these differences remained significant throughout the observation period. The levels of five acute-phase proteins (α-2 macroglobulin, haptoglobin, serum amyloid P, procalcitonin, and tissue plasminogen activator) were significantly higher at 6 months than at baseline. No significant differences were observed among the three treatment modalities at any time point for any biochemical parameter. CONCLUSIONS Levels of several cytokines and acute-phase proteins significantly changed after treatment regardless of treatment modality. There was no evidence for a specific DSL- or PDT-enhanced expression of inflammatory mediators.

Two-piece zirconia implants supporting all-ceramic crowns: a prospective clinical study.

Objectives The aim of this prospective clinical study is to evaluate the safety and efficacy of a new all-ceramic implant system to replace missing teeth in partially edentulous patients. Material and methods Thirty-two partially edentulous, systemically healthy patients were treated with 49 two-piece zirconia implants (ZERAMEX® T Implant System). Zirconia abutments were connected with adhesive resin cement. Single-unit full-ceramic crowns were cemented. The cases have been followed for 588±174 days after loading (range 369–889 days). All patients have been re-evaluated 1 year after loading. Results The cumulative survival rate 1 year after loading was 87% implants. All failures were the result of aseptic loosening, and no implants were lost after the first year. The results of the other cases were good, and the patients were very satisfied. The cumulative soft tissue complication rate was 0%, the cumulative technical complication rate was 4% implants, the cumulative complication rate for bone loss >2 mm was 0%, and the cumulative esthetic complication rate was 0%. Including the data from 20 patients treated with an earlier version of the system, an over-all 2-year cumulative survival rate of 86% was calculated for a total of 76 two-piece zirconia implants supporting all-ceramic crowns in 52 patients. Conclusions Replacement of single teeth in the posterior area was possible with this new full-ceramic implant system. Failures were due to aseptic loosening.

Are There Specific Benefits of Amoxicillin Plus Metronidazole in Aggregatibacter actinomycetemcomitans-Associated Periodontitis? Double-Masked, Randomized Clinical Trial of Efficacy and Safety

BACKGROUND It has been suggested that prescription of amoxicillin plus metronidazole in the context of periodontal therapy should be limited to patients with specific microbiologic profiles, especially those testing positive for Aggregatibacter actinomycetemcomitans. The main purpose of this analysis is to determine if patients positive for A. actinomycetemcomitans with moderate to advanced periodontitis benefit specifically from amoxicillin plus metronidazole given as an adjunct to full-mouth scaling and root planing. METHODS This is a double-masked, placebo-controlled, randomized longitudinal study including 41 participants who were positive for A. actinomycetemcomitans and 41 participants who were negative for A. actinomycetemcomitans. All 82 patients received full-mouth periodontal debridement performed within 48 hours. Patients then received either systemic antibiotics (375 mg amoxicillin and 500 mg metronidazole, three times daily) or placebo for 7 days. The primary outcome variable was persistence of sites with a probing depth (PD) >4 mm and bleeding on probing (BOP) at the 3-month reevaluation. Using multilevel logistic regression, the effect of the antibiotics was analyzed according to the following factors (interaction effect): A. actinomycetemcomitans-positive or -negative at baseline, sex, age, smoking, tooth being a molar, and interdental location. RESULTS At reevaluation, participants in the test group had significantly fewer sites with a persisting PD >4 mm and BOP than control patients (P <0.01). Being A. actinomycetemcomitans-positive or -negative did not change the effect of the antibiotics. Patients benefited from the antibiotics irrespective of sex, age, or smoking status. Molars benefited significantly more from the antibiotics than non-molars (P for interaction effect = 0.03). CONCLUSIONS Patients who were positive for A. actinomycetemcomitans had no specific benefit from amoxicillin plus metronidazole. Sites on molars benefited significantly more from the antibiotics than non-molar sites.

Differential Benefits of Amoxicillin- Metronidazole in Different Phases of Periodontal Therapy in a Randomized Controlled Crossover Clinical Trial

BACKGROUND The specific advantage of administering systemic antibiotics during initial, non-surgical therapy or in the context of periodontal surgery is unclear. This study assesses the differential outcomes of periodontal therapy supplemented with amoxicillin-metronidazole during either the non-surgical or the surgical treatment phase. METHODS This is a single-center, randomized placebo-controlled crossover clinical trial with a 1-year follow-up. Eighty participants with Aggregatibacter actinomycetemcomitans-associated moderate to advanced periodontitis were randomized into two treatment groups: group A, antibiotics (500 mg metronidazole plus 375 mg amoxicillin three times per day for 7 days) during the first, non-surgical phase of periodontal therapy (T1) and placebo during the second, surgical phase (T2); and group B, placebo during T1 and antibiotics during T2. The number of sites with probing depth (PD) >4 mm and bleeding on probing (BOP) per patient was the primary outcome. RESULTS A total of 11,212 sites were clinically monitored on 1,870 teeth. T1 with antibiotics decreased the number of sites with PD >4 mm and BOP per patient significantly more than without (group A: from 34.5 to 5.7, 84%; group B: from 28.7 to 8.7, 70%; P <0.01). Twenty patients treated with antibiotics, but only eight treated with placebo, achieved a 10-fold reduction of diseased sites (P = 0.007). Consequently, fewer patients of group A needed additional therapy, the mean number of surgical interventions was lower, and treatment time in T2 was shorter. Six months after T2, the mean number of residual pockets (group A: 2.8 ± 5.2; group B: 2.2 ± 5.0) was not significantly different and was sustained over 12 months in both groups. CONCLUSION Giving the antibiotics during T1 or T2 yielded similar long-term outcomes, but antibiotics in T1 resolved the disease quicker and thus reduced the need for additional surgical intervention.

Systemic Biomarkers in 2-Phase Antibiotic Periodontal Treatment A Randomized Clinical Trial

Accumulating evidence suggests that periodontal infections may have an impact on systemic health. In patients with untreated periodontitis, very high values for several inflammatory markers in serum are expressed simultaneously. We investigated to what extent these peak values change after nonsurgical and surgical periodontal treatment, with adjunctive antibiotics administered during the first or the second treatment phase. In a single-center, randomized, placebo-controlled, and double-masked clinical trial, 80 patients with chronic or aggressive periodontitis were randomized into 2 treatment groups: group A, receiving systemic amoxicillin and metronidazole during the first, nonsurgical phase of periodontal therapy (phase 1), and group B, receiving the antibiotics during the second, surgical phase (phase 2). Serum samples were obtained at baseline (BL), 3 mo after phase 1 (M3), and 6 and 12 mo after phase 2 (M6, M12). Samples were evaluated for 15 cytokines and 9 acute-phase proteins using the Bio-Plex bead array multianalyte detection system. For each analyte, peak values were defined as greater than mean +2 SD of measurements found in 40 periodontally healthy persons. Sixty-six patients showed a peak value of at least 1 analyte at BL. At M12, the number of these patients was only 36 (P = 0.0002). This decrease was stronger in group A (BL: 35, M12: 19, P = 0.0009) than in group B (BL: 31, M12: 17, P = 0.14). Twenty patients displayed peak values of at least 4 biomarkers at BL. The nonsurgical therapy delivered in the first phase reduced most of these peaks (group A, BL: 9, M3: 4, P = 0.17; group B, BL: 11, M3: 2, P = 0.01), irrespective of adjunctive antibiotics. The reductions obtained at M3 were maintained until M12 in both groups. Initial, nonsurgical periodontal therapy reduced the incidence of peak levels of inflammatory markers. Antibiotics and further surgical therapy did not enhance the effect (Clinicaltrials.gov NCT02197260).

Acute necrotising gingivitis in young children from villages with and without noma in Niger and its association with sociodemographic factors, nutritional status and oral hygiene practices: results of a population-based survey

Background Previous studies have suggested that acute necrotising gingivitis precedes noma disease and that noma clusters in some villages in certain regions of low- and middle-income countries. We sought to assess the prevalence of gingivitis with bleeding in young children from villages with or without a history of noma and to analyse epidemiological differences related to sociodemographic characteristics, nutritional status and oral hygiene practices. Methods We conducted a cross-sectional study in 440 children aged between 2 and 6 years from four villages in the Zinder region of southeast Niger in Africa. In two villages, cases of noma have repeatedly been detected; in the other two, noma has never been identified. We randomly selected 110 participants from each village. Results The prevalence of acute necrotising gingivitis was significantly higher in the noma villages compared with the non-noma villages (6.8% vs 0.9%; p=0.001). We found differences between the four villages regarding socioeconomic factors, stunting, undernourishment and oral hygiene practices. The type of oral hygiene procedures influenced the amount of dental plaque and gingival inflammation. Children using sand, coal or other abrasive products instead of a toothbrush had a significantly increased likelihood to be diagnosed with acute necrotising gingivitis (p=0.041). Conclusions Our data suggest that efforts to prevent noma should focus on populations with a high prevalence of acute necrotising gingivitis and include nutritional support and attempts to introduce safe and efficient oral hygiene practices to improve gingival health.

Effect of Periodontal Therapy With Amoxicillin-Metronidazole on Pharyngeal Carriage of Penicillin- and Erythromycin-Resistant Viridans Streptococci.

BACKGROUND Previous studies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal therapy. The purpose of this analysis is to assess changes in resistance patterns of the commensal Gram-positive microbiota. The viridans group streptococci (VGS) have been suggested to serve as reservoirs of resistance genes for more pathogenic streptococci and may be implicated in some non-oral infections. METHODS In this randomized clinical trial, 80 patients with periodontitis are distributed randomly into two groups. In group A, patients received 375 mg amoxicillin and 500 mg metronidazole three times per day for 7 days during the non-surgical treatment phase (T1). In group B, the antibiotics were administered during the surgical phase (T2). Resistance of VGS to penicillin and erythromycin was determined by the epsilometer test. RESULTS At baseline, VGS from 12.5% (group A) and 11.8% (group B) of patients had a minimum inhibitory concentration (MIC) >2 μg/mL to penicillin. Three months after T1, VGS from 15.6% and 16.7% of patients had an MIC >2 μg/mL, respectively. Six months after T2 VGS from 5.9% and 5.9% and 12 months after T2 VGS from 6.1% and 6.3% patients had an MIC >2 μg/mL. There was no effect of therapy with antibiotics, administered either in T1 or T2, on the carriage of penicillin-resistant VGS. Erythromycin resistance was high at baseline and remained unchanged throughout the study. MICs for penicillin and erythromycin were correlated (P <0.05). CONCLUSION Amoxicillin plus metronidazole did not significantly affect the resistance pattern of the VGS to penicillin or erythromycin.

Microbiologic Response to Periodontal Therapy and Multivariable Prediction of Clinical Outcome

BACKGROUND This study assesses the microbiologic effects of a two-phase antimicrobial periodontal therapy and tested microbiologic, clinical, and biologic markers as prognostic indicators for clinical success. METHODS Eighty patients with chronic or aggressive periodontitis received periodontal treatment supplemented with 375 mg amoxicillin plus 500 mg metronidazole, three times daily for 7 days. In group A, antibiotics were given during the first non-surgical phase (T1); in group B, antibiotics were given during the second surgical phase (T2). Six microorganisms, group assignment, demographic and clinical variables, peak values of 15 cytokines, and nine acute-phase proteins in serum were evaluated as potential predictors of at least one site with probing depth (PD) >4 mm and bleeding on probing (BOP) at 12 months post-therapy. RESULTS T1 decreased the counts of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia (Pi), and Treponema denticola significantly more in group A than group B. Aggregatibacter actinomycetemcomitans and Parvimonas micra (Pm) showed a significant decrease only if the treatment was supplemented with antibiotics, i.e., T1 in group A, or T2 in group B. After T2, differences between groups were no longer significant. A multivariable model including four parameters revealed a predictive value of Pm (odds ratio [OR] = 4.38, P = 0.02) and Pi (OR = 3.44, P = 0.049) and yielded moderate accuracy for predicting the treatment outcome (area under the curve = 0.72). Host-derived factors and treatment sequence were not significantly associated with the outcome. CONCLUSIONS Long-term microbiologic outcomes of periodontal therapy with adjunctive antibiotics either in T1 or T2 were similar. Detection of Pm before therapy was a predictor for persistence of sites with PD >4 mm and BOP at 12 months post-treatment.