Comparison of repeated applications of aPDT with amoxicillin and metronidazole in the treatment of chronic periodontitis: A short-term study.

AIM: The aim of this study was to compare the clinical effects of Metronidazole (MTZ) combined with Amoxicillin (AMX) and repeated applications of antimicrobial photodynamic therapy (aPDT) as an adjuvant for the treatment of chronic periodontitis. METHODS: A double-blind controlled and randomized clinical trial was conducted in 34 patients. All of the patients were treated with scaling and root planing (SRP) and separated into 2 groups: the MTZ+AMX Group (n=17), who received SRP and the systemic use of MTZ (400mg 3×per day for 7days) and AMX (500mg 3×per day for 7days), and the aPDT Group (n=17), who received SRP and three aPDT applications at all sites with a probing depth≥5mm immediately, at 48 and 96h after scaling and placebo pills over the span of 7days. Clinical examinations were performed at baseline and 90days post-therapy. The clinical parameters of bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were measured. The aPDT was conducted using methylene blue and a low-level laser (GaAlAs 660nm, 100mW, 48s, and 160J/cm2) in all sites with a probing depth≥5mm. A statistical analysis was also performed (α=5%). RESULTS: There was a significant improvement in CAL only in the intermediate pocket in the aPDT group compared to the MTZ+AMX group between baseline and 90days post-treatment (p=0.01). There was a reduction of both BOP and the percentage of residual pockets at 90days after treatment compared with baseline in both groups (p<0.05). CONCLUSION: Both proposed adjuvant therapies associated with conventional mechanical treatment in patients with chronic periodontitis were equally effective in terms of the gain of clinical insertion, control of inflammation and elimination of residual pockets.

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.

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.

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.

Treatment of residual pockets with photodynamic therapy, diode laser, or deep scaling. A randomized, split-mouth controlled clinical trial.

The objective of this work was to compare the effects of antimicrobial photodynamic therapy (PDT), diode soft laser therapy (DSL), and thorough deep scaling and root planing (SRP) for treatment of residual pockets. Thirty-two subjects with a history of non-surgical treatment for chronic periodontitis were included. Residual pockets >4 mm and bleeding upon probing were debrided with an ultrasonic device and then subjected to either PDT, DSL, or SRP. Pocket probing depth (PPD), bleeding on probing (BOP), and gingival recession were monitored over 6 months. Counts of four microorganisms were determined by direct hybridization with RNA probes. PPD decreased from 5.6 ± 1.0 to 3.8 ± 1.1 in 6 months (p < 0.001), and BOP decreased from 100% to 52% (p < 0.01). The risk for a site to remain >4 mm with BOP depended on initial PPD (p = 0.036) and was higher if treated with DSL (p = 0.034). Frequencies of three microorganisms were significantly lower in PDT- and SRP-treated than in DSL-treated quadrants (p = 0.02) after 14 days, but not at months 2 and 6. All three treatments resulted in a significant clinical improvement. PDT and SRP suppressed Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola stronger, and resulted in fewer persisting pockets after 6 months, than DSL application.

Antimicrobial advances in treating periodontal diseases.

Antibiotics are generally an efficient means of treating bacterial infections, and therefore are an obvious candidate in the treatment of periodontal diseases. Systemically and locally administered antimicrobial agents of all kinds have been evaluated in multiple clinical trials. The vast majority of studies have tested antibiotics as adjuncts to non-surgical debridement. No regime has demonstrated superiority over systemically administered amoxicillin and metronidazole in the treatment of any clinically or microbiologically defined variant of periodontal disease. The frequency and consequences of adverse effects of antibiotics have always to be balanced against the potential consequences of not rapidly suppressing a periodontal infection. Proposed strategies to reduce the risk of bacterial antimicrobial resistance include: prescribing two drugs with a synergistic or complementary effect, the administration of antibiotics at a high dose for a short period, a combined approach with mechanical debridement to disrupt biofilms, and the focus on therapeutic rather than prophylactic use. Derivatives of existing antibiotic classes and new compounds that act on unique targets are the subject of preclinical investigations with a focus on action against antibiotic-resistant medical pathogens. In light of the excellent results of a combination therapy with well-established drugs that are cheap and efficient, clinical trials should compare newly proposed protocols for periodontal therapy to a positive control. Future studies should focus not only on the action against the microorganisms directly involved in periodontal diseases, but also on those relevant to other medical concerns.

Amoxicillin and metronidazole as an adjunct to full-mouth scaling and root planing of chronic periodontitis.

BACKGROUND: It has been suggested that scaling and root planing of all pockets within a few hours and chlorhexidine treatments (full-mouth disinfection) may reduce the need for supplementary therapies. The aim of this study was to evaluate the clinical benefit of amoxicillin and metronidazole administered immediately after completion of full-mouth periodontal debridement in patients with chronic periodontitis. METHODS: This was a single-center, double-masked, placebo-controlled, randomized longitudinal study of 6 months' duration. Fifty-one patients received full-mouth periodontal debridement, performed within 48 hours. Twenty-five subjects received metronidazole, 500 mg, and amoxicillin, 375 mg, three times a day for 7 days; 26 subjects received a placebo. RESULTS: Forty-seven patients could be followed up to month 6. No differences in clinical parameters were noted before treatment. The overall mean probing depth decreased from 4.3 +/- 0.4 mm to 3.0 +/- 0.2 mm in the test group and from 4.4 +/- 0.4 mm to 3.1 +/- 0.3 mm in the control group (P = 0.05, difference between groups). More importantly, test subjects had a significantly lower mean number of persisting pockets >4 mm and bleeding on probing that required further treatment (P = 0.005): 6 months after full-mouth debridement plus antibiotics, only 0.4 +/- 0.8 persisting pockets were still present, whereas 3.0 +/- 4.3 persisting pockets were still present in the control group. The protective risk of the antibiotics for having more than one pocket deeper than 4 mm and bleeding on probing per subject after 6 months was 8.85. CONCLUSION: Systemic metronidazole and amoxicillin significantly improved the 6-month clinical outcomes of full-mouth non-surgical periodontal debridement, thus significantly reducing the need for additional therapy.

Local antimicrobial therapy after initial periodontal treatment.

AIM: The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy. METHODS: Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox trade mark, Elyzol Dental Gel or PerioChip at all residual periodontal pockets with a probing depth >/= 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters. RESULTS: Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol Dental Gel [0.03 mm +/- 0.09 (SD)](p = 0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip application did not differ significantly from that obtained following the application of Atridox(p = 0.27). Of the sites treated with Atridox, 42% gained >/= 1 mm PAL and 9% >/= 2 mm PAL as opposed to the sites treated with Elyzol Dental Gel, in which 34% gained >/= 1 mm PAL and 8% gained >/= 2 mm PAL. Of the sites treated with PerioChip, 36% gained >/= 1 mm and 6% gained >/= 2 mm PAL following a completed initial periodontal therapy. CONCLUSIONS: The application of the three biodegradable sustained release devices tested following initial periodontal therapy resulted in a statistically significant gain in mean PAL for AtridoxTM and a significant reduction in PPD for all three devices during the study period. Furthermore, when sites treated with Atridox were compared with sites treated with Elyzol, a significant difference in mean PAL gain (0.3 mm) was observed.