Clinical and microbiological effects of different antimicrobials on generalized aggressive periodontitis

AIM: To evaluate and compare the effects of adjunctive metronidazole plus amoxicillin, doxycycline and metronidazole on clinical and microbiological parameters in patients with generalized aggressive periodontitis. MATERIAL AND METHODS: Forty-three patients participated in this randomized clinical trial divided into four groups. Six weeks after scaling and root planning (SRP), groups 1-3 received adjunctive metronidazole, plus amoxicillin, doxycycline and metronidazole respectively, and group 4 acted as controls. Clinical recordings concerning probing depth, probing attachment level and bleeding on probing were performed at baseline, 6 weeks after SRP and 6 months from baseline. Subgingival samples were analysed using the 'checkerboard' DNA-DNA hybridization for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Tannerella forsythia and Treponema denticola. Results: All treatments resulted in improvement of clinical parameters (ANOVA p > 0.05). Systemic administration of metronidazole plus amoxicillin or metronidazole resulted in statistically significant greater reduction of the proportion of sites > 6 mm than SRP (z-test, p < 0.05). These antimicrobials yielded a significant effect on levels of important periodontal pathogens for 6 months. CONCLUSION: Adjunctive metronidazole plus amoxicillin or metronidazole alone (when A.actinomycetemcomitans is not involved) is effective in deep pockets of aggressive periodontitis patients.     

Debridement and local application of tetracycline-loaded fibres in the management of persistent periodontitis: results after 12 months

BACKGROUNDS, AIMS: The aim of our study was to evaluate the clinical, radiological and microbiological response to the local delivery of tetracycline (TE) of sites with persistent periodontal lesions. MATERIALS AND METHODS: The study was conducted in a split-mouth design. Nineteen patients with at least four bilateral pockets 4-5 mm and bleeding on probing (BOP) were treated with scaling and root planing (SRP) plus TE fibres (test sites) or with SRP alone (control sites). Clinical and radiological measurements were taken at baseline, 6 months and 12 months post-operatively. Subgingival plaque samples were collected at baseline, at fibres removal, 6 and 12 months following treatment and analysed by polymerase chain reaction. RESULTS: Both treatments yielded a statistically significant (p<0.05) reduction of probing depth (2.05 and 1.21 mm), gain of clinical attachment level (1.71 and 0.53 mm) and reduction of BOP scores (23.68% and 57.89%) for TE and SRP groups, respectively, when comparing 12-month data with baseline. The differences between two groups were significant. The prevalence of Treponema denticola and Bacteroides forsythus decreased after therapy in both groups but only in the test sites Actinobacillus actinomycetemcomitans and Prevotella intermedia were not yield detected. The pathogens could be eliminated from five periodontal pockets by SRP alone, while 21 TE sites were not recolonized at 12 months. CONCLUSIONS: SRP plus TE fibres gave the greatest advantage in the treatment of periodontal persistent lesions at least 12 months following treatment.     

Comparison of clinical outcomes following treatment of chronic adult periodontitis with subgingival scaling or subgingival scaling plus metronidazole gel

BACKGROUND, AIMS: Conventional treatment of chronic periodontitis involves mechanical debridement of periodontal pockets. Recently, subgingival antimicrobials have been used adjunctively following such debridement. This 2-centre study compared the clinical effects of subgingival scaling (SRP) with SRP plus subgingival application of 25% metronidazole gel, Elyzol (SRP+gel), in patients with chronic adult periodontitis. METHOD: Voluntary informed written consent was obtained from 45 subjects at the Eastman (mean age 46, range 34-63) and 43 subjects at RAF Halton (mean age 47, range 34-71) who participated in this blind, randomised split-mouth design study. All had at least 2 sites in each quadrant with probing pocket depth (PPD) > or = 5 mm. PPD, bleeding on probing (BOP), and clinical probing attachment levels (CAL) measured using a stent, were recorded at baseline and at 1, 3, 6 and 9 months post-therapy. After subgingival scaling of all quadrants, 2 quadrants were randomly selected to be treated with metronidazole gel. RESULTS: A paired t-test on baseline values showed no bias between groups. Both treatments effectively reduced the signs of periodontitis. At each follow-up visit, reduction in PPD, CAL and BOP after the combined treatment was greater than for SRP alone. Paired t-tests showed that the improvement in the SRP+gel group was statistically significantly better (p<0.001) than for SRP alone (mean 0.5 +/- 0.6 mm. 95% CI 0.4-0.6 mm.) Similarly, the % of sites which improved to a final pocket depth of < or = 3 mm and the % of sites which improved over the 9 months of the study by as much as > or = 2 mm were greater for SRP+gel than for SRP alone. CONCLUSIONS: At the end of the study, the mean reductions for PPD were 1.0 mm (SRP) compared to 1.5 mm (SRP+gel), and for CAL they were 0.4 mm (SRP) compared to 0.8 mm (SRP+gel), with mean difference for CAL between treatments of 0.4 +/- 0.6 mm (95% confidence intervals of 0.3-0.6 mm). The combination therapy of SRP+gel was superior to the conventional treatment of SRP alone, and these differences were maintained for 9 months.     

牙周基础治疗对慢性牙周炎患者临床指标及5种牙周可疑致病微生物的影响

目的:观察牙周基础治疗对临床指标及5种牙周可疑致病微生物的影响。方法:选取20例慢性牙周炎患者(40个位点),在治疗前和基础治疗后3个月时检测观测位点的临床指标牙周探诊深度(PPD),临床附着丧失(CAL)和探诊出血(BOP),同时采集龈下微生物样本。采用PCR和反杂交的方法对所采集微生物样本中的牙龈卟啉单胞菌、福赛斯坦纳菌,中间普氏菌、伴放线放线杆菌和齿垢密螺旋体进行半定量检测。结果:通过牙周基础治疗后临床指标PPD及BOP的改善具有统计学意义(P<0.001),而CAL的改善不具有统计学意义。治疗后牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的检出量显著减少(P<0.05或P<0.001)。治疗前PPD>6mm的位点只有福赛斯坦纳菌在治疗后比治疗前有显著减少(P<0.05),而牙龈卟啉单胞菌和齿垢密螺旋体的变化不具有统计学意义。结论:基础治疗是治疗慢性牙周炎的有效方法,可改善临床指标,减少龈下牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的数量。但在PPD>6mm的位点基础治疗对于这五微生物的影响作用是有限的。     

Topical metronidazole application as an adjunct to scaling and root planing

AIM: This study was carried out to investigate the effect of 2 applications of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling with root planing. METHOD: 59 of the original collective of 64 patients with adult periodontitis were observed for a 9-month period. This randomised single-blind study was carried out in split-mouth design. Each patient had to have at least 2 pockets with a probing depth of > or =5 mm in each quadrant. The clinical parameters, pocket probing depth (PPD), attachment level (AL) and bleeding on probing (BOP), were recorded at all teeth on days 0, 91, 175 and 259; in addition, subgingival plaque samples taken from 45 patients were analysed by means of dark-field microscopy. Therapy comprised subgingival scaling and root planing (SRP) of all quadrants and additional application of metronidazole 25%, dental gel in 2 randomly selected quadrants (SRP+Metro). Treatment was confined to teeth with a baseline PPD of > or =5 mm. Average PPD and AL and the incidence of BOP were computed for all pockets with a baseline PPD of > or =5 mm, and the 2 methods compared. The main efficacy variable for evaluation of the 2 treatments was the difference in PPD on day 259. RESULTS: Comparison of the 2 treatments revealed a statistically significant improvement in the clinical parameters for both treatment methods over the study period. Between baseline and day 259, significant differences in PPD (SRP+Metro: from 6.00 to 4.63 mm, SRP: from 6.02 to 4.83 mm) and BOP (SRP+Metro: from 67 to 31%, SRP: from 64 to 36%) were observed between the 2 treatment groups. Evaluation according to different patient groups demonstrated significant advantages of the combined therapy in previously-untreated patients, especially in female probands. Dark-field microscopy revealed a shift in the bacterial flora towards "healthy conditions". CONCLUSIONS: The results show that only minor advantages are to be gained from the application of a metronidazole 25% dental gel as adjunctive therapy to subgingival scaling. The distinctly better results of combined therapy in previously-untreated patients calls for more thorough investigation.     

Topical use of a metronidazole gel in the treatment of sites with symptoms of recurring chronic inflammation

BACKGROUND: Bacterial plaque accumulation at the dentogingival junction and in periodontal pockets is the major etiologic factor in all manifestations of periodontal disease. The aim of this study was to evaluate whether a locally delivered 25% metronidazole gel after scaling and root planing (SRP) would enhance the treatment outcome over SRP alone in periodontal pockets with symptoms of recurring chronic inflammation. METHODS: Twenty-one maintenance-care patients, 10 men and 11 women, having at least one pair of contralateral anatomically matching proximal tooth surfaces showing probing depth > or = 5 mm and bleeding on probing (BOP), were included in the study. The sites were randomized to be treated with SRP plus 25% metronidazole gel (test sites) or with SRP alone (control sites) in a split-mouth design. Clinical evaluations were performed immediately pretreatment (baseline) and at 3 and 6 months post-treatment. RESULTS: Both treatments yielded a statistically significant (P = 0.001) reduction in probing depth (1.9 and 1.8 mm), gain of attachment level (1.6 and 1.0 mm), and reduction of BOP (38.1% and 33.3%) for test and control sites, respectively, at 6 months. There was no statistically significant difference between the treatments for any of the clinical parameters. CONCLUSION: This study indicates that a locally applied 25% metronidazole gel does not improve the treatment outcome over SRP alone in sites with recurring chronic inflammation in maintenance-care patients.     

Microbiological markers for prediction and assessment of treatment outcome following non-surgical periodontal therapy

BACKGROUND: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus are considered major putative periodontal pathogens. However, it remains unclear what combinations or what levels of these bacteria influence treatment outcome. The purpose of the present study was to establish useful pathogenic markers for prediction and assessment of treatment outcome following scaling and root planing (SRP). METHODS: A total of 1,149 sites in 104 chronic periodontitis patients were clinically examined at baseline. Three months after SRP, 606 sites in 56 of these patients were reexamined. Subgingival plaque samples taken from the examined sites at baseline and 3 months were analyzed for the detection and quantification of A. actinomycetemcomitans, P. gingivalis, and B. forsythus using a colorimetric polymerase chain reaction technique. RESULTS: At baseline, high levels and a combination of P. gingivalis and B. forsythus were frequently detected in diseased sites (74%). SRP reduced the levels and the coexistence of P. gingivalis and B. forsythus (from 75% to 43%). However, in treated sites where there was less reduction of probing depth (<2 mm), or where bleeding on probing (BOP) or suppuration was detected, residual coexistence of P. gingivalis and B. forsythus and a high level of P. gingivalis after SRP were significantly more frequent. Furthermore, SRP did not improve BOP at sites exhibiting initially high levels of A. actinomycetemcomitans. CONCLUSIONS: These results suggest that the combination of P. gingivalis and B. forsythus, as well as the level of P. gingivalis, is useful in assessing treatment outcome. Furthermore, the high level of A. actinomycetemcomitans before SRP is a possible valuable predictor of treatment outcome.     

Timing affects the clinical outcome of adjunctive systemic antibiotic therapy for generalized aggressive periodontitis

BACKGROUND: Systemic antibiotics improve the outcome of scaling and root planing (SRP) in patients exhibiting severe periodontitis. This study evaluated the influence of timing of adjunctive systemic antibiotics in the sequence of periodontal therapy. METHODS: Two cohorts of patients with generalized aggressive periodontitis and treated by SRP, adjunctive antibiotics, and supportive periodontal therapy (SPT) were analyzed retrospectively. Cohort A (17 patients; 36 +/- 5 years of age) received systemic amoxicillin/metronidazole immediately after SRP ("immediate"); cohort B (17 patients; 36 +/- 4 years of age) received the same regimen 3 months after SRP, following SPT, including subgingival reinstrumentation ("late"). Clinical parameters, including probing depth (PD), relative attachment level (RAL), bleeding on probing (BOP), and suppuration, were recorded with a pressure-sensitive electronic probe at baseline and 3 and 6 months after SRP. RESULTS: Significant time*group interactions were found for all clinical parameters except BOP, i.e., timing of antibiotic therapy affected the course of clinical changes over time. Immediate antibiotic therapy produced significantly higher initial changes (0 to 3 months) in PD and RAL. Late antibiotic therapy at 3 months resulted in additional significant improvements in all clinical parameters between 3 and 6 months. In initially deep sites (baseline PD >6 mm), improvements in PD and RAL over 6 months were significantly higher with immediate antibiotic therapy compared to late antibiotic therapy. CONCLUSION: Within the limits of a retrospective analysis, these findings indicate that administration of amoxicillin/metronidazole immediately after initial SRP provides more PD reduction and RAL "gain" in initially deep sites than late administration at SPT with reinstrumentation after 3 months.     

Effects of metronidazole in patients with "refractory" periodontitis associated with Bacteroides forsythus

Abstract The aim of the present study was to monitor the microbiological and clinical effects of renewed supra and sub gingival debridement in conjunction with systemic metronidazole therapy (500 mg TID for 7 days) in 27 “refractory” periodontitis patients, culture positive for Bacteroides forsythus and negative for Actinobacillus actinomycetemcomitans. Clinical evaluation included assessment of plaque, bleeding upon probing, probing pocket depth and clinical attachment loss at the deepest, bleeding site in each quadrant. Microbiological evaluation was carried out by anaerobic cultivation of sub gingival plaque samples from the same sites. 6 months after renewed debridement and systemic metronidazole (RD + M). a statistically significant improvement of all clinical parameters was observed, except for the plaque index. After RD + M, B. forsythus was suppressed below detection level in 17 of the 27 patients, P. gingivalis in 9 out of 15 patients and P. intermedia in 14 of the 21 patients. Before RD+M. 12 patients harboured simultaneously B. forsythus, P. gingivalis as well as P. intermedia. Out of these 6 patients were culture negative for the 3 species after therapy and showed the greatest reduction in pocket depth (3.1 mm) and gain of clinical attachment level (2.5 mm). In the treatment of refractory periodontitis. associated with patients culture positive for B. forsythus and negative for A. actinomycetemcomitans, metronidazole can significantly improve the clinical and microbiological parameters.     

Effect of a controlled-release chlorhexidine chip on clinical and microbiological parameters of periodontal syndrome

AIM: The aim of this study was to evaluate the effectiveness of a controlled-released chlorhexidine chip (CHX) as adjunctive therapy to scaling and root planing (SRP) in the treatment of chronic periodontitis. MATERIAL AND METHODS: Twenty patients with at least four sites with probing depth >or= 5 mm and bleeding on probing were selected. This randomized single-blind study was carried out in parallel design. The control group received SRP alone, while the test group received SRP plus CHX chip. The clinical parameters, Plaque Index (PlI), Papillary Bleeding Score (PBS), Bleeding on Probing (BOP), Gingival Recession (GR), Probing Depth (PD) and Relative Attachment Level (RAL), and the microbiological parameter BANA test were recorded at baseline and after 3, 6 and 9 months. RESULTS: Both groups presented significant improvements in all parameters analyzed over the study period. There were no statistically significant differences between the two groups for any parameter analyzed after 9 months, except for BOP, which was significantly reduced in the control group. The mean reductions on PD and RAL were 2.4 mm and 1.0 mm for the control group and 2.2 mm and 0.6 mm for the test group, respectively. CONCLUSION: The CHX chip did not provide any clinical or microbiological benefit beyond that achieved with conventional scaling and root planning, after a 9-month period.     

Topical metronidazole application compared with subgingival scaling

Abstract The aim of this study was to compare the topical application of a metronidazole 25% dental gel with subgingival scaling. 30 patients from the recall program participated in this open randomised study with split-mouth design. Pocket probing depths (PPD) and bleeding on probing (BOP) were measured before and 2, 12 and 24 weeks after the end of the treatment period. In addition, subgingival plaque samples were taken from all mesial sites and analysed with dark-field microscopy. All patients had at least 1 tooth in each quadrant with a PPD of 5 mm or more that should bleeding on probing, when entering the study. The treatment consisted of 2 applications of the dental gel in 2 randomly selected quadrants (on days 0 and 7) as well as simultaneous subgingival scaling of the remaining quadrants. Oral hygiene instruction was given on day 21. The average PPD and the average frequency of BOP were calculated for all sites with an inital PPD of 5 mm or more and continued at each examination, using the same sites. The statistical analyses showed that both treatments were effective in reducing PPD and BOP over the 6-month period. At the end of the follow-up period, the mean reduction in PPD was 1.3 mm after gel treatment and 1.5 mm after subgingival scaling. BOP was reduced by 35% and 42%, respectively. No significant differences between the 2 treatments were detected. Dark-field microscopy showed a shift towards a more healthy microflora for both treatment modalities; this persisted throughout the 6-month period. Application of a 25% metronidazole dental gel on recall patients seems to be as effective on the investigated clinical and microbiological parameters as subgingival scaling.     

Amoxicillin plus metronidazole in the treatment of adult periodontitis patients. A double-blind placebo-controlled study

BACKGROUND, AIMS: The aim of this double-blind, parallel study was to evaluate the adjunctive effects of systemically administered amoxicillin and metronidazole in a group of adult periodontitis patients who also received supra- and subgingival debridement. METHODS: 49 patients with a diagnosis of generalised severe periodontitis participated in the study. Random assignment resulted in 26 patients in the placebo (P) group with a mean age of 40 years and 23 patients in the test (T) group which had a mean age of 45 years. Clinical measurements and microbiological assessments were taken at baseline and 3 months after completion of initial periodontal therapy with additional placebo or antibiotic treatment. Patients received coded study medication of either 375 mg amoxicillin in combination with 250 mg metronidazole or identical placebo tablets, every 8 hours for the following 7 days. RESULTS: At baseline, no statistically significant differences between groups were found for any of the clinical parameters. Except for the plaque, there was a significantly larger change in the bleeding, probing pocket depth (PPD) and clinical attachment level (CAL) in the T-group as compared to the P-group after therapy. The greatest reduction in PPD was found at sites with initial PPD of > or = 7 mm, 2.5 mm in the P-group and 3.2 mm in the T-group. The improvement in CAL was most pronounced in the PPD category > or = 7 mm and amounted to 1.5 mm and 2.0 mm in the P- and T-groups, respectively. No significant decrease was found in the number of patients positive for any of the test species in the P-group. The number of patients positive for Porphyromonas gingivalis, Bacteroides forsythus and Prevotella intermedia in the T-group showed a significant decrease. After therapy there was a significant difference between the P- and the T- group in the remaining number of patients positive for P. gingivalis, B. forsythus and Peptostreptococcus micros. 4 subgroups were created on the basis of the initial microbiological status for P. gingivalis positive (Pg-pos) and negative patients (Pg-neg) in the P- and the T-groups. The difference in reduction of PPD between Pg-pos and Pg-neg patients was particularly evident with respect to the changes in % of sites with a probing pocket depth > or = 5 mm. This % decreased from 45% at baseline to 23% after treatment in the Pg-pos placebo subgroup and decreased from 46% to 11% in the Pg-pos test subgroup (p < or = 0.005). In contrast, the changes in the proportions of sites with a probing pocket depth > or = 5 mm in the Pg-neg placebo and Pg-neg test subgroup were similar, from 43% at baseline to 18% after treatment versus 40% to 12% respectively. CONCLUSIONS: This study has shown that systemic usage of metronidazole and amoxicillin, when used in conjunction with initial periodontal treatment in adult periodontitis patients, achieves significantly better clinical and microbiological results than initial periodontal treatment alone. Moreover, this research suggests that especially patients diagnosed with P. gingivalis benefit from antibiotic treatment.     

A 2-step non-surgical procedure and systemic antibiotics in the treatment of rapidly progressive periodontitis

BACKGROUND: In the last few years knowledge about periodontal infections has increased enormously, nevertheless practitioners are still seeking guidelines for suitable treatment concepts. METHODS: The aim of this study was to examine the effect of doxycycline, metronidazole, and clindamycin used adjunctively in a 2-step nonsurgical procedure in patients with rapidly progressive periodontitis (RPP). The first step included scaling, root planing, and polishing (SRP) in each quadrant using 4 to 5 visits. The second step included full-mouth enhanced root planing (RP) and wound dressing in 1 or 2 visits after SRP and the beginning of antibiotic therapy. Forty-eight patients (mean age 32.4 years) with generalized RPP, with an average of 16 sites with probing depths (PD) deeper than 8 mm, and high counts of Porphyromonas gingivalis were randomly assigned to 4 different groups: group 1 (doxycycline) n = 12, group 2 (metronidazole) n = 15, group 3 (clindamycin) n = 11, and group 4 (control group; no antibiotic treatment) n = 10. Clinical evaluations, including plaque index (PI), sulcus bleeding index (SBI), probing depth (PD), clinical attachment level (CAL), and bacteriological and crevicular cell sampling, were done at baseline (BL), 3 weeks after SRP, and 6 and 24 months after RP. RESULTS: After the first step (SRP), we observed an improvement of PI and SBI in all 4 groups, but did not see any statistically significant PD reduction 3 weeks after SRP compared to baseline. However, 6 and 24 months after the second step (RP) we observed a significantly greater reduction of PD in groups 2 and 3 and a significantly greater CAL gain in comparison to groups 1 and 4. After 24 months, the attachment level gain in group 1 and group 4 was less than 1.5 mm, and less than 1.0 mm in PD site categories 6 to 9 mm and >9 mm. PI showed no significant difference between the groups throughout the period after SRP until 24 months, compared to 3 weeks after SRP. SBI decreased most in the metronidazole and clindamycin groups. P. gingivalis and Actinobacillus actinomycetemcomitans were almost completely eradicated in these 2 groups 24 months after RP. In addition, the phagocytotic capacity of crevicular polymorphonuclear neutrophils was increased in groups 2 and 3 after the second step. CONCLUSIONS: The present results show that metronidazole and clindamycin are effective antibiotics when used adjunctively in a 2-step nonsurgical procedure of scaling and root planing in RPP patients.     

Clinical and microbiological effect of scaling and root planing in smoker and non-smoker chronic and aggressive periodontitis patients

OBJECTIVES: To compare the effects of scaling and root planing (SRP) on clinical and microbiological parameters at selected sites in smoker and non-smoker chronic and generalized aggressive periodontitis patients. MATERIALS AND METHODS: Clinical parameters including probing depth (PD), relative attachment level (RAL), and bleeding upon probing (BOP), and subgingival plaque samples were taken from four sites in 28 chronic periodontitis (CP) and 17 generalized aggressive periodontitis (GAgP) patients before and after SRP. Polymerase chain reaction assays were used to determine the presence of A. actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia and Treponema denticola. RESULTS: Both CP and GAgP non-smokers had significantly greater reduction in pocket depth (1.0+/-1.3 mm in CP smokers versus 1.7+/-1.4 mm in non-smokers, p=0.007 and 1.3+/-1.0 in GAgP smokers versus 2.4+/-1.2 mm in GAgP non-smokers, p<0.001) than respective non-smokers, with a significant decrease in Tannerella forsythensis in CP sites (smokers 25% increase and non-smokers 36.3% decrease, p<0.001) and Prevotella intermedia at GAgP sites (smokers 25% reduction versus 46.9% in non-smokers, p=0.028). CONCLUSION: SRP was effective in reducing clinical parameters in both groups. The inferior improvement in PD following therapy for smokers may reflect the systemic effects of smoking on the host response and the healing process. The lesser reduction in microflora and greater post-therapy prevalence of organisms may reflect the deeper pockets seen in smokers and poorer clearance of the organisms. These detrimental consequences for smokers appear consistent in both aggressive and CP.     

Comparative clinical and microbiological effects of subgingival metronidazole application in adult periodontitis; 12-months results

The aim of the present study was to evaluate the clinical and microbiological effects of subgingival application of 25% metronidazole dental gel as an adjunct to scaling and root planing (SRP) in the treatment of adult periodontitis. Eighty teeth in 18 patients were evaluated using a split mouth design. The test teeth received SRP and a 25% metronidazole gel applied subgingivally on days 0 and 7. The control teeth received SRP only. Clinical and microbiological examinations were carried out before treatment and on weeks 1, 3, 7, 13, 26, 38 and 52 of the experimental period. Colony forming units of Porphyromonas gingivalis and Prevotella intermedia / Prevotella nigrescens were determined. Both treatments provided significant improvements in all the clinical and microbiological parameters (P<0.05). However, none of the differences between the study groups were statistically significant (P > 0.05). As a conclusion, the present study does not provide evidence in favour of the routine use of adjunctive metronidazole dental gel in the treatment of adult periodontitis.     

牙龈卟啉单胞菌与牙周基础治疗关系的实验研究

目的应用TaqMan实时荧光定量聚合酶链反应法检测慢性牙周炎患者牙周洁刮治术（SRP）治疗前后龈下菌斑中牙龈卟啉单胞菌（P. gingivalis）的变化,分析P. gingivalis与SRP疗效之间的关系,探讨应用实时荧光定量聚合酶链反应监测和评价SRP的可能性。方法选择20例中重度慢性牙周炎患者为研究对象,检查SRP治疗前后的临床指标,包括探诊深度（PD）、临床附着丧失（CAL）和探诊出血（BOP）;采集SRP治疗前后的龈下菌斑共142个样本,应用TaqMan实时荧光定量聚合酶链反应检测样本中的P. gingivalis。构建含有P. gingivalis扩增片段的重组质粒,建立定量标准。结果慢性牙周炎患者SRP治疗后PD、CAL和BOP均明显下降（P<0.001）;治疗前P. gingivalis检出率为80.28%,治疗后下降为54.23%;治疗前P. gingivalis数量与PD相关,Kendall相关系数为0.70（P<0.001）,治疗后牙周袋内细菌数量明显减少（P<0.001）。治疗前牙周袋内P. gingivalis的定植数量与PD、CAL和BOP的改善无相关性（P>0.05）,但治疗后治疗有效位点P. gingivalis数量减少程度明显大于治疗无效位点（P<0.05）,细菌减少量与PD改善弱相关（r=0.25,P=0.04）。结论SRP治疗可以明显改善临床症状,降低P. gingivalis检出率和绝对数量;治疗前P. gingivalis定植水平对临床指标的改善没有影响,治疗后P. gingivalis数量下降程度可以反映治疗效果。TaqMan实时荧光定量聚合酶链反应可以用于牙周炎治疗效果的监测和评价。     

Periodontal debridement as a therapeutic approach for severe chronic periodontitis: a clinical, microbiological and immunological study

Aim: To clinically, microbiologically and immunologically characterize periodontal debridement as a therapeutic approach for severe chronic periodontitis.
Material and Methods: Twenty-five patients presenting at least eight teeth with a probing pocket depth (PPD) of 5 mm and bleeding on probing (BOP) were selected and randomly assigned to quadrant-wise scaling and root planing or one session of full-mouth periodontal debridement. The following clinical outcomes were assessed: plaque index, BOP, position of gingival margin, relative attachment level (RAL) and PPD. Real-time PCR was used for quantitative analysis of Aggregatibacter actinomycetemcomitans , Porphyromonas gingivalis and Tannerella forsythia . The enzyme-linked immunosorbent assay permitted the detection of IL-1 β , prostaglandin E₂, INF- γ and IL-10 in gingival crevicular fluid (GCF). All the parameters were evaluated at baseline, and at 3 and 6 months after treatment.
Results: Both the groups had similar means of PPD reduction and attachment gain over time. Besides a significant reduction in the bacterial level after treatment in both groups, microbiological analysis failed to demonstrate significant differences between them. Finally, no difference was observed between groups with respect to the levels of inflammatory mediators in GCF.
Conclusion: Periodontal debridement resulted in a similar clinical, microbiological and immunological outcome when compared with standard scaling and root planing and therefore may be a viable approach to deal with severe chronic periodontitis.     

The use of metronidazole and amoxicillin in the treatment of advanced periodontal disease

Abstract. The present clinical trial was performed to study the effect of systemic administration of metronidazole and amoxicillin as an adjunct to mechanical therapy in patients with advanced periodontal disease. 16 individuals, 10 female and 6 male, aged 35–58 years, with advanced periodontal disease were recruited. A baseline examination included assessment of clinical. radiographical, microbiological and histopathological characteristics of periodontal disease. The 16 patients were randomly distributed into 2 different samples of 8 subjects each. One sample of subjects received during the first 2 weeks of active periodontal therapy, antibiotics administered via the systemic route (metronidazole and amoxicillin). During the corresponding period, the 2nd sample of subjects received a placebo drug (placebo sample). In each of the 16 patients, 2 quadrants (1 in the maxilla and 1 in the mandible) were exposed to non-surgical subgingival scaling and root planing. The contralateral quadrants were left without subgingival instrumentation. Thus, 4 different treatment groups were formed; group 1: antibiotic therapy but no scaling, group 2: antibiotic therapy plus scaling, group 3: placebo therapy but no scaling, group 4: placebo therapy plus scaling. Re-examinations regarding the clinical parameters were performed, samples of the subgingival microbiota harvested and 1 soft tissue biopsy from 1 scaled and 1 non-scaled quadrant obtained 2 months and 12 months after the completion of active therapy. The teeth included in groups 1 and 3 were following the 12-month examination exposed to non-surgical periodontal therapy, and subsequently exited from the study. Groups 2 and 4 were also re-examined 24 months after baseline. The findings demonstrated that in patients with advanced periodontal disease, systemic administration of metronidazole plus amoxicillin resulted in (i) an improvement of the periodontal conditions, (ii) elimination/suppression of putative periodontal pathogens such as A. actinomycetemcomitans, P. gingivalis, P. intermedia and (iii) reduction of the size of the inflammatory lesion. The antibiotic regimen alone, however, was less effective than mechanical therapy with respect to reduction of BoP—positive sites, probing pocket depth reduction, probing attachment gain. The combined mechanical and systemic antibiotic therapy (group 2) was more effective than mechanical therapy alone in terms of improvement of clinical and microbiological features of periodontal disease.     

Hand instrumentation versus ultrasonic debridement in the treatment of chronic periodontitis: a randomized clinical and microbiological trial

Aim: To compare the effectiveness of scaling and root planing (SRP) with the use of hand instruments to that of non-surgical treatment with the use of an ultrasonic device, using clinical and microbiological criteria.
Material and Methods: Thirty-three patients with chronic periodontitis participated in this randomized-controlled clinical trial divided into two groups. Patients in the control group received SRP with hand instruments, whereas patients in the test group received ultrasonic debridement (UD). Clinical recordings concerning probing pocket depth, clinical attachment level, plaque index and gingival bleeding index were performed at baseline, 3 and 6 months after baseline. Subgingival samples were analysed using the "checkerboard" DNA–DNA hybridization technique for Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola .
Results: Both treatments resulted in a significant improvement in all clinical recordings. Three months after treatment, a numerical decrease was observed for P. gingivalis, T. forsythia and T. denticola in both groups, which was statistically significant only for P. gingivalis ( p <0.05). Inter-group differences were observed at 6 months for T. forsythia and T. denticola ( p <0.05), favouring SRP.
Conclusions: Both treatment modalities provided comparable clinical results in the treatment of chronic periodontitis.     

Clinical responses to subgingival application of a metronidazole 25% gel compared to the effect of subgingival scaling in adult periodontitis

Abstract. A newly developed metronidazole 25% dental gel was compared with subgingival scaling in the treatment of adult periodontitis. 206 patients in 9 centres participated in the study. Probing pocket depth (PPD) and bleeding on probing (BOP) were recorded before treatment and 2, 6, 12, 18, and 24 weeks after the treatment. All patients had at least I tooth in each quadrant with a PPD of 5 mm or more. The treatments consisted of 2 applications of dental gel (days 0 and 7) in 2 randomly selected quadrants (split mouth design) and 2 sessions of subgingival scaling (1 quadrant on day 0, and 1 quadrant on day 7). Instruction in oral hygiene was given 2 weeks after completed treatment. The average PPD and the average frequency of BOP were calculated over all sites with initial PPD of 5 mm or more. PPD and BOP were thus, at each examination, calculated from the same sites. The mean PPD was 5.9 mm before gel application and 5.8 mm before scaling (p= 0.31). BOP was 88% in both treatment groups. 24 weeks after the treatment. PPD and BOP were significantly reduced in both groups and for both parameters (p < 0.01). PPD was reduced by 1.3 mm after gel application and 1.5 mm after scaling; BOP was reduced by 32% and 39%, respectively. The difference between the treatments was statistically significant, but considered as clinically unimportant.