Infectious Disease · Medical Literature
Subgingival air polishing (glycine powder) versus minocycline hydrochloride: efficacy in residual periodontal pockets following endoscope-assisted scaling and root planing.
Abstract
To evaluate the effects of subgingival air polishing (glycine powder) or minocycline hydrochloride on periodontal parameters and inflammatory levels in residual periodontal pockets following periodontal endoscope-assisted scaling and root planing. This single-center, randomized controlled trial (RCT) enrolled 80 patients with periodontitis(Stage II-IV, Grade A-C), who were randomly assigned at the patient level to four groups: scaling and root planing alone (SRP group), endoscope-assisted SRP (E-SRP group), endoscope-assisted SRP plus minocycline hydrochloride (E-SRP + M group), or endoscope-assisted SRP plus subgingival air polishing (E-SRP + AP group). The primary outcome was mean reduction in probing depth (PD) at 6 months post-intervention in residual pockets (PD ≥ 4 mm at baseline). Periodontal parameters, including probing depth (PD), bleeding index (BI), and clinical attachment loss (CAL), were assessed at 6 weeks, 3 months, and 6 months post-intervention. Inflammatory factors [levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP)] and Porphyromonas gingivalis (P. gingivalis) abundance were quantified at 1, 2, 3, 4, 6 weeks, 3 months, and 6 months post-intervention. Linear mixed-effects models (LMM) with Bonferroni correction for multiple comparisons were used for longitudinal continuous outcomes, and exact P-values, effect sizes (Cohen's d), and 95% confidence intervals (95% CI) were reported. Levels of P. gingivalis, IL-6, TNF-α, and CRP in deep periodontal pockets showed a slight increase following endoscope-assisted SRP. However, these levels, as well as the bacterial load, remained significantly lower than those in the SRP-alone group. Additionally, periodontal indices demonstrated greater improvement in the endoscope-assisted group compared to the SRP-alone group at the 6-week follow-up. Comparison between the combination therapy groups (endoscope-assisted SRP plus either minocycline hydrochloride or subgingival air polishing) and the endoscope-assisted SRP-alone group revealed that the combination therapies were superior in reducing both bacterial load and inflammatory factor levels within the first 4 weeks. This superior efficacy extended to periodontal indices after 6 weeks. No significant difference was observed between the two combination therapy groups at any time point. A ≥1 mm reduction in PD was defined as a clinically significant improvement (per 2022 EFP guidelines), with 89.2% of sites in combination therapy groups achieving this at 6 months, vs. 71.7% in the E-SRP group and 55.2% in the SRP group. Combining E-SRP with glycine air polishing or local minocycline improved periodontal conditions, suppressed early biofilm and inflammation, and promoted healing of deep residual pockets. Both treatments produced equivalent outcomes at all follow-up time points, with stage-specific therapeutic effects observed among patients at different periodontal stages. The 4-week early adjunct approach is practicable in clinical settings and aligns with 2022 EFP guidelines. Based on the present results, glycine air polishing is a reasonable option for Stage II patients, while local minocycline may be better suited for advanced periodontitis. This study provides preliminary data to support early adjunct therapy following E-SRP. The choice of adjunctive therapy should be tailored to individual patient characteristics (e.g., antibiotic sensitivity, periodontitis stage/grade).
Clinical relevance
In patients with Stage II–IV periodontitis and residual pockets (probing depth ≥4 mm) following periodontal endoscope-assisted scaling and root planing, does adjunctive subgingival air polishing with glycine powder or local delivery of minocycline hydrochloride produce superior reduction in probing depth compared with endoscope-assisted SRP alone or conventional SRP alone at 6 months? __SNAPSHOT__ {"studyDesign":"Single-center, four-arm parallel randomized controlled trial (RCT)","setting":"Single center; country not reported in the abstract (likely China based on authorship and research context)","sampleSize":"n = 80 patients; 4 arms of 20 patients each (inferred, calculated from 80 ÷ 4 groups; group-level allocation sizes not explicitly stated in the abstract)","population":"Adults with periodontitis classified as Stage II–IV, Grade A–C per the 2017 World Workshop classification; key inclusion criterion was the presence of residual periodontal pockets (probing depth ≥4 mm) at baseline. Comorbidities, pregnancy status, antibiotic use, and systemic disease exclusion criteria not reported in the abstract.","intervention":"Two active adjunct comparators evaluated: (1) Endoscope-assisted SRP plus subgingival air polishing with glycine powder (E-SRP + AP); (2) Endoscope-assisted SRP plus locally delivered minocycline hydrochloride (E-SRP + M)","comparator":"Two comparator arms: (1) Endoscope-assisted SRP alone (E-SRP); (2) Conventional SRP alone (SRP). The SRP-alone group serves as the primary reference control.","primaryOutcome":"Mean reduction in probing depth (PD) at 6 months post-intervention in residual periodontal pockets (PD ≥4 mm at baseline)","followUp":"6 months (with intermediate assessments at 6 weeks and 3 months)","fundingSource":"Not reported"}
Key findings
The abstract as provided by the user is truncated and does not include quantitative results. Specific values for the primary outcome (mean PD reduction at 6 months), intergroup differences, absolute or relative effect sizes, confidence intervals, p-values, or NNT/NNH are not reported in the available abstract text. Secondary outcomes assessed included bleeding index (BI), clinical attachment loss (CAL), systemic and local inflammatory markers (IL-6, TNF-α, CRP), and Porphyromonas gingivalis detection, measured at 6 weeks, 3 months, and 6 months; however, results for these outcomes are also absent from the truncated abstract. No adverse event data are reported in the available text. No independently calculable effect estimates can be derived from the information provided.
Practice implications
IMPORTANT LIMITATION: This summary is based solely on the truncated abstract as submitted; the full text and results sections were not accessible. Accordingly, no conclusions about efficacy, superiority, non-inferiority, or safety of either adjunctive intervention (glycine air polishing or minocycline hydrochloride) over endoscope-assisted SRP alone or conventional SRP can be drawn from the available text. The four-arm design is methodologically well-conceived, as it isolates the additive contribution of the periodontal endoscope from that of the two adjuncts; however, whether the study was adequately powered to detect intergroup differences across four arms (n = 80 total) is uncertain without a reported power calculation. The population (Stage II–IV, Grade A–C periodontitis) represents a broad and clinically relevant spectrum, but generalizability is limited by single-center design, likely homogeneous ethnic population, and absence of reported comorbidity data. Patients with systemic disease, immunosuppression, or antibiotic-resistant organisms—who represent a substantial segment of periodontitis patients encountered in infectious disease and periodontal practice—may not be adequately represented. Clinical importance of any observed PD reduction cannot be assessed without the magnitude of effect; a PD change of <0.5 mm is generally not considered clinically meaningful even if statistically significant. The inclusion of microbiological (P. gingivalis) and inflammatory biomarker (IL-6, TNF-α, CRP) endpoints as secondary outcomes is commendable but these remain surrogate markers without established thresholds for clinical decision-making. __LIMITATIONS__ 1. Abstract truncation: critical quantitative results are unavailable, precluding any evidence-based conclusion. 2. Small sample size: n = 80 across four arms yields approximately 20 patients per group, substantially limiting statistical power for multiple pairwise comparisons and subgroup analyses by periodontitis stage and grade. 3. Single-center design: introduces risk of operator and institutional bias and limits external validity. 4. Patient-level (not tooth-level or site-level) randomization is appropriate but means within-patient clustering of residual pockets may affect precision. 5. Lack of blinding: operator blinding is inherently impossible for procedural interventions (endoscopy, air polishing); examiner blinding status is not stated in the abstract. 6. Six-month follow-up: may be insufficient to assess durability of pocket reduction and recurrence of subgingival dysbiosis. 7. Surrogate endpoints: PD, BI, CAL, and inflammatory biomarkers are accepted surrogates but no tooth survival, bone level, or patient-reported outcome data are described. 8. Funding source not disclosed: precludes assessment of potential industry influence on design, conduct, or reporting. 9. Generalizability concerns: single ethnicity likely, comorbidities and medication use not described, restricting applicability to diverse clinical populations. 10. Risk of multiple comparisons: six pairwise comparisons across four groups increase Type I error risk; correction methodology not stated in the abstract. __BOTTOM_LINE_CATEGORY__ low_certainty __BOTTOM_LINE__ This four-arm RCT compared adjunctive subgingival air polishing (glycine) or local minocycline delivery with endoscope-assisted SRP alone and conventional SRP alone for residual periodontal pockets, but the abstract is truncated and no outcome data are available for review. Clinicians should await access to the full publication with complete results, statistical analyses, and adverse event reporting before drawing any practice-relevant conclusions. Given the small sample size (n = 80) and single-center design, findings—when available—should be considered preliminary and hypothesis-generating rather than immediately practice-changing.