Paeeriodontics. The past. Microbiology. Part (III)

The occurrence of peri-implant mucositis associated with the shift of submucosal microbiome in patients with a history of periodontitis during the first two years

AIM

To investigate the dynamic changes of peri-implant microbiome in patients with a history of periodontitis and to construct a microbial prediction model.

MATERIALS AND METHODS

The prospective study was performed at one month (T1), one year (T2) and two years (T3) after restoration. Clinical examinations [probing depth (PD), bleeding on probing (BOP), suppuration (SUP)], radiographic examinations and sample collection were conducted at three timepoints. Peri-implant sulcular fluid (PISF) was collected and analysed by 16S rRNA gene sequencing. Generalized linear mixed model (GLMM) was used to identify differences.

RESULTS

Totally, 168 subjects were assessed for eligibility. Twenty-two patients were recruited in the longitudinal study. Eventually, 67 PISF samples from 24 implants of 12 patients were collected and analysed. Peri-implant microbiome showed increasing diversity and complexity over time. Disease-associated genera Porphyromonas, Tannerella, Treponema and Prevotella dramatically increased from T1 to T3. The prediction model for clinical suppuration at T1 showed a high accuracy of 90%.

CONCLUSION

The dysbiosis of peri-implant microbiome increased with time during the two-year observation in patients with a history of periodontitis. Genera of Porphyromonas, Tannerella, Treponema and Prevotella were biomarkers of peri-implant mucositis. Microbiota at the early stage could predict subsequent microbial dysbiosis and clinical suppuration.

The effect of supragingival glycine air polishing on periodontitis during maintenance therapy: a randomized controlled trial

Background

Glycine air polishing has been proved to be safe, comfortable and time-saving. Whether it could substitute ultrasonic scaling to remove dental plaque biofilm during periodontal maintenance remains unclear. The purposes of this study were to evaluate the effect of supragingival glycine air polishing (SGAP) on the subgingival periodontal pathogens during maintenance therapy and to check the association of periodontal pathogens and clinical parameters.

Methods

Twenty-three chronic periodontitis patients during their maintenance therapy were enrolled in the 12-week study. According to randomized split-mouth design, the test side was treated with SGAP (65 μm), while the control side was treated with supragingival ultrasonic scaling and polishing (SUSP) with rubber cup. Clinical examination including plaque index (PLI), probing depth (PD), bleeding index (BI) were performed at baseline and 12 weeks post-treatment. Sampling of the subgingival plaque at each investigational site (mesiobuccal site of the mandibular first molar) was performed at baseline and 2, 4, 8, 12 weeks after maintenance treatment. Four periodontal pathogens including Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Fusobacterium nucleatum were detected by 16S rDNA polymerase chain reaction.

Results

Clinical status generally improved after treatment in both groups. PLI in both groups, PD in SGAP group and bleeding on probing (%) in SUSP group significantly decreased after treatment (p < 0.05). There was no significant difference of clinical parameters between two groups before and after treatment. The detection rates of P. gingivalis, T. denticola in both groups, T. forsythia in SUSP group and F. nucleatum in SGAP group decreased after maintenance treatment in both groups, although no significant difference was found, and it rebound to baseline level at 12 weeks after maintenance treatment. There was no significant difference between SGAP group and SUSP group at any time point. T. denticola-positive sites had significantly greater BI than T. denticola-negative sites (p < 0.05).

Discussion

Supragingival glycine air polishing had a reliable effect in removing subgingival dental plaque biofilm during maintenance period, and three months may be a proper maintenance interval for pockets not more than 5 mm.

Effects on gingivitis of daily rinsing with 1.5% H2O2

The purpose of this study was to compare 2 groups of adolescents undergoing orthodontic treatment with fixed appliances to determine whether once daily use of a mouthrinse containing 1.5% H2O2 along with toothbrushing would be better than toothbrushing alone in maintaining their periodontal health. The 2 groups of subjects were selected non-randomly but were matched for age and sex. The control group (N = 34) used toothbrushing and a mint-flavored 0.05% NaF mouthrinse once daily, while the treatment group (N = 25) used toothbrushing and a once daily rinse with a preparation containing 0.05% NaF and 1.5% H2O2 (Orthoflur). 2 calibrated clinical examiners made single-blind clinical assessments of the plaque index, gingival index, and bleeding tendency in 6 standard sites per subject. They also noted any generalized mucosal irritations or staining of the teeth or tongue. Assessments were made before appliances were placed (baseline) and 1, 3, 6, 9, 12 and 18 months after appliances were placed. Results indicated that although there were no significant differences at baseline, the Orthoflur group had significantly fewer study sites with gingival indes or bleeding tendency scores greater than 1 than the control group from the 1-month through the 18-month examinations (P less than 0.01), and significantly fewer sites with plaque index greater than 1 and bleeding tendency scores of 2 or more from the 3-month through the 18-month examinations (P less than 0.02 and 0.01, respectively). No generalized mucosal irritations or clinically significant staining of the tongue or teeth were noted in either group during the study.

Use of antimicrobial containing acrylic strips in the treatment of chronic periodontal disease. A three month follow-up study

Local antimicrobial therapy has been considered for use in the treatment of chronic periodontal disease. This study evaluated chlorhexidine, metronidazole, and tetracycline delivered into periodontal pockets in an acrylic resin vehicle and compared the results with root planed and untreated sites over a three-month follow-up period. One site per patient where pocketing greater than or equal to 6 mm associated with a single rooted tooth was randomly allocated to one of the five possible regimens. Baseline and follow-up measurements included probing depth, loss of attachment, bleeding on probing, crevicular fluid flow, and dark-field microscopy of a subgingival plaque sample. Intratreatment evaluations revealed no significant changes in any parameter for untreated sites. Significant improvements in many parameters occurred with all four therapies although the magnitude and duration were greater in metronidazole and root planing groups. The more important intertreatment comparisons indicated that most treatments produced significant benefits compared with the control group; however, again these were greater with metronidazole and root planing. Furthermore, significantly greater effects were noted for metronidazole and root planing compared with tetracycline and more particularly chlorhexidine. It is concluded that some locally delivered antimicrobials alone may be useful in the treatment of chronic periodontal disease. However, at this time local antimicrobial therapy should be considered as adjunctive to conventional debridement techniques.

Chlorhexidine compared with other locally delivered antimicrobials. A short review

Based on the association of bacterial plaque with the initiation of chronic gingivitis and progression of chronic periodontitis, chemical antiplaque agents have been employed both in prevention of periodontal disease and its treatment. In supragingival plaque control regimens, chlorhexidine has not been superceded as a chemical anti-plaque agent, although other compounds have been shown to be useful. The local side-effects of chlorhexidine and other cationic antiseptics, however, limit their long-term use for prevention. Extrinsic tooth staining in particular remains the greatest problem. Short-term anti-plaque uses for chlorhexidine include as an adjunct to mechanical cleaning in the initial oral hygiene phase of treatment, in situations where mechanical oral hygiene is difficult, including postsurgery, intermaxillary fixation, fixed orthodontic therapy, physically and mentally handicapped individuals, systemic diseases with oral manifestations such as leukaemia. More recent interest in chlorhexidine has resulted from the delivery of compounds subgingivally in the treatment of chronic periodontitis. Such methods have extended the use of chlorhexidine into areas inaccessible to the action of antimicrobial drugs delivered locally by conventional means, such as tooth brushing or mouth rinsing. Available evidence suggests that chlorhexidine may not be as effective as some antimicrobial drugs whose activity is more specific for those organisms considered particularly pathogenic to the periodontal tissues.