Short-term effects of systemic antibiotics during periodontal healing

OBJECTIVES: To investigate the short-term effects of nonsurgical therapy (scaling and root planing, SRP) on the subgingival microbiota in chronic (CP) and aggressive (AP) periodontal disease. METHOD AND MATERIALS: Ninety-seven CP and AP subjects underwent full-mouth SRP on 2 consecutive days. AP patients were randomly assigned to either receive systemic metronidazole plus amoxicillin (AP+AB) or were treated mechanically alone (AP). Pathogens were identified with 16S rRNA oligodeoxynucleotide probes and dot-blot hybridization before and at days 2, 3, 4, 7, 10, and 21 of healing. CP subjects were treated by scaling and root planing along with placebo tablets. RESULTS: Initially, AP cell counts were 69.9- (Porphyromonas gingivalis), 10.2- (Aggregatibacter actinomycetemcomitans), 5.7- (Tannerella forsythia), and 3.3-fold (Prevotella intermedia) enhanced compared to CP cell counts. Following SRP, immediate elimination occurred in single individuals of all three treatment groups at day 2. After SRP plus antibiotic therapy (AP+AB), the prevalence scores dropped beyond the levels of AP and CP, beginning at day 7, and remained low until day 21 (P =or< .05). Clinical healing statistically benefited from SRP with no differences among the three treatment groups. CONCLUSION: Nonsurgical therapy resulted in both a suppression and early elimination of single taxa immediately after completion of active treatment. Systemic antibiotics significantly accelerate the suppression of the periodontal microflora, but have limited effect on the elimination of target isolates during healing.

Oral microbiota in Swiss adolescents

OBJECTIVES: The purpose of the study was to determine the prevalence of different oral microbes in gingival plaque samples and in samples from the dorsum of the tongue in a Swiss adolescent population. MATERIALS AND METHODS: Ninety-nine adolescents between 15 and 18 years were enrolled. Plaque index, bleeding on probing (BOP), the periodontal screening index, and decayed missed filled tooth (DMFT) index were recorded. Samples from subgingival plaque and swabs from the tongue were analyzed by the Checkerboard DNA-DNA hybridization method. Additionally, counts of Streptococus mutans and Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were determined by real-time PCR. RESULTS: Periodontitis was not diagnosed in any of the subjects but all of them presented signs of gingival inflammation displaying a mean BOP of 28%. Ten (10.1%) subjects were tested positive for P. gingivalis, each 22 (22.2%) for A. actinomycetemcomitans and T. forsythia, (47.5%) for T. denticola. T. denticola and S. mutans showed a high affinity to the gingival plaque, whereas T. forsythia was often detected from the dorsum of the tongue. DMFT was associated with S. mutans counts, and BOP correlated with counts of P. gingivalis and T. denticola. CONCLUSIONS: The present data indicate that: (a) gingivitis but not periodontitis is a common finding among Swiss adolescents, and (b) bacteria associated with periodontitis were frequently detected in the subgingival dental plaque and on the dorsum of the tongue in Swiss adolescents with gingivitis. CLINICAL RELEVANCE: Although gingivitis was a frequent finding in Swiss adolescents, periodontitis was not detected in this population. The dorsum of the tongue appears to represent an important reservoir for periodontopathic bacteria.

Microbiological composition associated with interleukin-1 gene polymorphism in subjects undergoing supportive periodontal therapy

BACKGROUND: Interleukin-1 gene polymorphism (IL-1 gene) has been associated with periodontitis. The present study examined the subgingival microbiota by IL-1 gene status in subjects undergoing supportive periodontal therapy (SPT). METHODS: A total of 151 subjects with known IL-1 gene status (IL-1A +4845/IL-1B -3954) (IL-1 gene) were included in this study. Clinical data and subgingival plaque samples (40 taxa) were collected. These taxa were determined by the checkerboard DNA-DNA hybridization method. RESULTS: Gender, smoking habits (n-par tests), age, and clinical periodontal conditions did not differ by IL-1 gene status. IL-1 gene-negative subjects had a higher total bacterial load (mean difference, 480.4 x 10(5); 95% confidence interval [CI], 77 to 884 x 10(5); P <0.02). The levels of Actinobacillus actinomycetemcomitans (mean difference, 30.7 x 10(5); 95% CI, 2.2 to 59.5 x 10(5); P <0.05), Eubacterium nodatum (mean difference, 4.2 x 10(5); 95% CI, 0.6 to 7.8 x 10(5); P <0.02), Porphyromonas gingivalis (mean difference, 17.9 x 10(5); 95% CI, 1.2 to 34.5 x 10(5); P <0.05), and Streptococcus anginosus (mean difference, 4.0 x 10(5); 95% CI, 0.2 to 7.2 x 10(5); P <0.05) were higher in IL-1 gene-negative subjects, an observation specifically found at sites with probing depths <5.0 mm. CONCLUSIONS: Bleeding on probing did not differ by IL gene status, reflecting clinical SPT efficacy. IL-1 gene-negative subjects had higher levels of periodontal pathogens. This may suggest that among subjects undergoing SPT, a lower bacterial load is required in IL-1 gene-positive subjects to develop the same level of periodontitis as in IL-1 gene-negative subjects.

Similarities in the Subgingival Microbiota Assessed by a Curet Sampling Method at Sites With Chronic Periodontitis

Background: The goal of this study was to determine whether site-specific differences in the subgingival microbiota could be detected by the checkerboard method in subjects with periodontitis. Methods: Subjects with at least six periodontal pockets with a probing depth (PD) between 5 and 7 mm were enrolled in the study. Subgingival plaque samples were collected with sterile curets by a single-stroke procedure at six selected periodontal sites from 161 subjects (966 subgingival sites). Subgingival bacterial samples were assayed with the checkerboard DNA-DNA hybridization method identifying 37 species. Results: Probing depths of 5, 6, and 7 mm were found at 50% (n = 483), 34% (n = 328), and 16% (n = 155) of sites, respectively. Statistical analysis failed to demonstrate differences in the sum of bacterial counts by tooth type (P = 0.18) or specific location of the sample (P = 0.78). With the exceptions of Campylobacter gracilis (P <0.001) and Actinomyces naeslundii (P <0.001), analysis by general linear model multivariate regression failed to identify subject or sample location factors as explanatory to microbiologic results. A trend of difference in bacterial load by tooth type was found for Prevotella nigrescens (P <0.01). At a cutoff level of >/=1.0 x 10(5), Porphyromonas gingivalis and Tannerella forsythia (previously T. forsythensis) were present at 48.0% to 56.3% and 46.0% to 51.2% of sampled sites, respectively. Conclusions: Given the similarities in the clinical evidence of periodontitis, the presence and levels of 37 species commonly studied in periodontitis are similar, with no differences between molar, premolar, and incisor/cuspid subgingival sites. This may facilitate microbiologic sampling strategies in subjects during periodontal therapy.

Does pregnancy have an impact on the subgingival microbiota?

BACKGROUND: We investigated clinical and subgingival microbiologic changes during pregnancy in 20 consecutive pregnant women > or =18 years not receiving dental care. METHODS: Bacterial samples from weeks 12, 28, and 36 of pregnancy and at 4 to 6 weeks postpartum were processed for 37 species by checkerboard DNA-DNA hybridization. Clinical periodontal data were collected at week 12 and at 4 to 6 weeks postpartum, and bleeding on probing (BOP) was recorded at sites sampled at the four time points. RESULTS: The mean BOP at week 12 and postpartum was 40.1% +/- 18.2% and 27.4% +/- 12.5%, respectively. The corresponding mean BOP at microbiologic test sites was 15% (week 12) and 21% (postpartum; not statistically significant). Total bacterial counts decreased between week 12 and postpartum (P <0.01). Increased bacterial counts over time were found for Neisseria mucosa (P <0.001). Lower counts (P <0.001) were found for Capnocytophaga ochracea, Capnocytophaga sputigena, Eubacterium saburreum, Fusobacterium nucleatum naviforme, Fusobacterium nucleatum polymorphum, Leptotrichia buccalis, Parvimonas micra (previously Peptostreptococcus micros or Micromonas micros), Prevotella intermedia, Prevotella melaninogenica, Staphylococcus aureus, Streptococcus anginosus, Streptococcus intermedius, Streptococcus mutans, Streptococcus oralis, Streptococcus sanguinis, Selenomonas noxia, and Veillonella parvula. No changes occurred between weeks 12 and 28 of pregnancy. Counts of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola did not change. Counts of P. gingivalis and T. forsythia at week 12 were associated with gingivitis (P <0.001). CONCLUSIONS: Subgingival levels of bacteria associated with periodontitis did not change. P. gingivalis and T. forsythia counts were associated with BOP at week 12. A decrease was found in 17 of 37 species from week 12 to postpartum. Only counts of N. mucosa increased.

Subgingival microbiota of Sri Lankan tea labourers naïve to oral hygiene measures.

AIM To characterize the subgingival microbiota within a cohort of adult males (n = 32) naïve to oral hygiene practices, and to compare the composition of bacterial taxa present in periodontal sites with various probing depths. MATERIAL AND METHODS Subgingival plaque samples were collected from single shallow pocket [pocket probing depth (PPD)≤3 mm] and deep pocket (PPD≥6 mm) sites from each subject. A polymerase chain reaction based strategy was used to construct a clone library of 16S ribosomal RNA (rRNA) genes for each site. The sequences of ca. 30-60 plasmid clones were determined for each site to identify resident taxa. Microbial composition was compared using a variety of statistical and bioinformatics approaches. RESULTS A total of 1887 cloned 16S rRNA gene sequences were analysed, which were assigned to 318 operational taxonomic units (98% identity cut-off). The subgingival microbiota was dominated by Firmicutes (69.8%), Proteobacteria (16.3%), and Fusobacteria (8.0%). The overall composition of microbial communities in shallow sites was significantly different from those within deep sites (∫-Libshuff, p < 0.001). CONCLUSIONS A taxonomically diverse subgingival microbiota was present within this cohort; however, the structures of the microbial communities present in the respective subjects exhibited limited variation. Deep and shallow sites contained notably different microbial compositions, but this was not correlated with the rate of periodontal progression.

Microbiota at teeth and implants in partially edentulous patients. A 10-year retrospective study.

OBJECTIVE To determine the microbiota at implants and adjacent teeth 10 years after placement of implants with a sandblasted and acid-etched surface. MATERIAL AND METHODS Plaque samples obtained from the deepest sites of 504 implants and of 493 adjacent teeth were analyzed for certain bacterial species associated with periodontitis, for staphylococci, for aerobic gram-negative rods, and for yeasts using nucleic acid-based methods. RESULTS Species known to be associated with periodontitis were detectable at 6.2-78.4% of the implants. Significantly higher counts at implants in comparison with teeth were assessed for Tannerella forsythia, Parvimonas micra, Fusobacterium nucleatum/necrophorum, and Campylobacter rectus. Higher counts of periodontopathogenic species were detectable at implants of current smokers than at those of non-smokers. In addition, those species were found in higher quantities at implants of subjects with periodontitis. The prevalence of Prevotella intermedia, Treponema denticola, C. rectus, and moreover of Staphylococcus warneri might be associated with peri-implant inflammation. Selected staphylococcal species (not Staphylococcus aureus), aerobic gram-negative rods, and yeasts were frequently detected, but with the exception of S. warneri, they did not show any association with periodontal or peri-implant diseases. CONCLUSIONS Smoking and periodontal disease are risk factors for colonization of periodontopathic bacteria at implants. Those bacterial species may play a potential role in peri-implant inflammation. The role of S. warneri needs further validation.

Significance of Periodontal Risk Assessment in the recurrence of periodontitis and tooth loss

Aim: To investigate the association of the Periodontal Risk Assessment (PRA) model categories with periodontitis recurrence and tooth loss during supportive periodontal therapy (SPT) and to explore the role of patient compliance. Material and Methods: In a retrospective cohort, PRA was performed for 160 patients after active periodontal therapy (APT) and after 9.5 ± 4.5 years of SPT. The recurrence of periodontitis and tooth loss were analysed according to the patient's risk profile (low, moderate or high) after APT and compliance with SPT. The association of risk factors with tooth loss and recurrence of periodontitis was investigated using logistic regression analysis. Results: In 18.2% of patients with a low-risk profile, in 42.2% of patients with a moderate-risk profile and in 49.2% of patients with a high-risk profile after APT, periodontitis recurred. During SPT, 1.61 ± 2.8 teeth/patient were lost. High-risk profile patients lost significantly more teeth (2.59 ± 3.9) than patients with moderate- (1.02 ± 1.8) or low-risk profiles (1.18 ± 1.9) (Kruskal–Wallis test, p=0.0229). Patients with erratic compliance lost significantly (Kruskal–Wallis test, p=0.0067) more teeth (3.11 ± 4.5) than patients compliant with SPT (1.07 ± 1.6). Conclusions: In multivariate logistic regression analysis, a high-risk patient profile according to the PRA model at the end of APT was associated with recurrence of periodontitis. Another significant factor for recurrence of periodontitis was an SPT duration of more than 10 years.

Clinical and Histological Evaluation of a Granular Bovine Bone Biomaterial Used as an Adjunct to Guided Tissue Regeneration With a Bioresorbable Bovine Pericardium Collagen Membrane in the Treatment of Intrabony Periodontal Defects

The aim of the present study is to evaluate the clinical and histologic healing of deep intrabony defects treated with guided tissue regeneration (GTR) with a collagen membrane from bovine pericardium and implantation of granular bovine bone biomaterial.

Healing of two and three wall intrabony periodontal defects following treatment with an enamel matrix derivative combined with autogenous bone

BACKGROUND: There are still limited data on the outcomes of regenerative periodontal surgery using a combination of an enamel matrix protein derivative (EMD) and autogenous bone (AB). AIM: To evaluate the healing of deep intrabony defects treated with either a combination EMD+AB or EMD alone. MATERIALS AND METHODS: Forty patients with advanced chronic periodontitis, with one deep intrabony defect, were randomly treated with either EMD+AB (test) or EMD (control). Clinical assessments were performed at baseline and at 1 year after treatment. The primary outcome variable was relative attachment level (RAL). RESULTS: Healing was uneventful in all patients. The test sites showed a reduction in the mean probing pocket depth (PPD) of 5.6 +/- 0.9 mm (p<0.001), a gain in the mean RAL of 4.2 +/- 1.1 mm (p<0.001) and a gain in the mean probing bone level (PBL) of 3.9 +/- 1.0 mm (p<0.001). The control group displayed a mean PPD reduction of 4.6 +/- 0.4 mm (p<0.001), a mean RAL gain of 3.4 +/- 0.8 mm (p<0.001) and a mean PBL gain of 2.8 +/- 0.8 mm (p<0.001). RAL gains of > or =4 mm were measured in 90% of the test defects and in 55% of the controls. PBL gains of > or =4 mm were obtained in 85% of the test defects and in 25% of the control ones. The test treatment resulted in statistically higher PPD reductions, RAL gains and PBL gains compared with the control (p<0.01). CONCLUSIONS: Within their limits, the present results indicate that: (i) at 1 year after surgery, both therapies resulted in statistically significant clinical improvements compared with baseline and (ii) although the combination of EMD+AB resulted in statistically significant higher soft and hard tissue improvements compared with treatment with EMD, the clinical relevance of this finding is unclear.

Clinical and histologic evaluation of granular Beta-tricalcium phosphate for the treatment of human intrabony periodontal defects: a report on five cases

BACKGROUND: The aim of the study is to clinically and histologically evaluate the healing of advanced intrabony defects treated with open flap debridement and the adjunct implantation of granular beta tricalcium phosphate (beta-TCP). METHODS: Five patients, each displaying advanced combined 1- and 2-wall intrabony defects around teeth scheduled for extraction or root resection, were recruited. Approximately 6 months after surgery, the teeth or roots were removed together with a portion of their surrounding soft and hard tissues and processed for histologic evaluation. RESULTS: The mean probing depth (PD) was reduced from 10.8 +/- 2.3 mm presurgically to 4.6 +/- 2.1 mm, whereas a mean clinical attachment level (CAL) gain of 5.0 +/- 0.7 mm was observed. The increase in gingival recession was 1.2 +/- 3.2 mm. The histologic evaluation indicated the formation of new cellular cementum with inserting collagen fibers to a varying extent (mean: 1.9 +/- 0.7 mm; range: 1.2 to 3.03 mm) coronal to the most apical extent of the root instrumentation. The mean new bone formation was 1.0 +/- 0.7 mm (range: 0.0 to 1.9 mm). In most specimens, beta-TCP particles were embedded in the connective tissue, whereas the formation of a mineralized bone-like or cementum-like tissue around the particles was only occasionally observed. CONCLUSION: The present data indicates that treatment of intrabony periodontal defects with this beta-TCP may result in substantial clinical improvements such as PD reduction and CAL gain, but this beta-TCP does not seem to enhance the regeneration of cementum, periodontal ligament, and bone.

A randomized, controlled clinical trial on the clinical, microbiological, and staining effects of a novel 0.05% chlorhexidine/herbal extract and a 0.1% chlorhexidine mouthrinse adjunct to periodontal surgery

BACKGROUND: Chlorhexidine (CHX) rinsing after periodontal surgery is common. We assessed the clinical and microbiological effects of two CHX concentrations following periodontal surgery. MATERIALS AND METHODS: In a randomized, controlled clinical trial, 45 subjects were assigned to 4 weeks rinsing with a 0.05 CHX/herbal extract combination (test) or a 0.1% CHX solution. Clinical and staining effects were studied. Subgingival bacteria were assessed using the DNA-DNA checkerboard. Statistics included parametric and non-parametric tests (p<0001 to declare significance at 80% power). RESULTS: At weeks 4 and 12, more staining was found in the control group (p<0.05 and p<0.001, respectively). A higher risk for staining was found in the control group (crude OR: 2.3:1, 95% CI: 1.3 to 4.4, p<0.01). The absolute staining reduction in the test group was 21.1% (9 5% CI: 9.4-32.8%). Probing pocket depth (PPD) decreases were significant (p<0.001) in both groups and similar (p=0.92). No rinse group differences in changes of bacterial counts for any species were found between baseline and week 12. CONCLUSIONS: The test CHX rinse resulted in less tooth staining. At the study endpoint, similar and high counts of periodontal pathogens were found.

Immune adaptations that maintain homeostasis with the intestinal microbiota

Humans harbour nearly 100 trillion intestinal bacteria that are essential for health. Millions of years of co-evolution have moulded this human-microorganism interaction into a symbiotic relationship in which gut bacteria make essential contributions to human nutrient metabolism and in return occupy a nutrient-rich environment. Although intestinal microorganisms carry out essential functions for their hosts, they pose a constant threat of invasion owing to their sheer numbers and the large intestinal surface area. In this Review, we discuss the unique adaptations of the intestinal immune system that maintain homeostatic interactions with a diverse resident microbiota.

Complication and failure rates of fixed dental prostheses in patients treated for periodontal disease

Objectives: To evaluate the biological and technical complication rates of fixed dental prostheses (FDP) with end abutments or cantilever extensions on teeth (FDP-tt/cFDP-tt) on implants (FDP-ii/cFDP-ii) and tooth-implant-supported (FDP-ti/cFDP-ti) in patients treated for chronic periodontitis. Material and methods: From a cohort of 392 patients treated between 1978 and 2002 by graduate students, 199 were re-examined in 2005. Of these, 84 patients had received ceramo-metal FDPs (six groups). Results: At the re-evaluation, the mean age of the patients was 62 years (36.2–83.4). One hundred and seventy-five FDPs were seated (82 FDP-tt, 9 FDP-ii, 20 FDP-ti, 39 cFDP-tt, 15 cFDP-ii, 10 cFDP-ti). The mean observation time was 11.3 years; 21 FDPs were lost, and 46 technical and 50 biological complications occurred. Chances for the survival of the three groups of FDPs with end abutments were very high (risk for failure 2.8%, 0%, 5.6%). The probability to remain without complications and/or failure was 70.3%, 88.9% and 74.7% in FDPs with end abutments, but 49.8–25% only in FDPs with extensions at 10 years. Conclusions: In patients treated for chronic periodontitis and provided with ceramo-metal FDPs, high survival rates, especially for FDPs with end abutments, can be expected. The incidence rates of any negative events were increased drastically in the three groups with extension cFDPs (tt, ii, ti). Strategic decisions in the choice of a particular FDP design and the choice of teeth/implants as abutments appear to influence the risks for complications to be expected with fixed reconstruction. If possible, extensions on tooth abutments should be avoided or used only after a cautious clinical evaluation of all options.