Research Summary

Analyzed using Evidence Intelligence™

Subgingival scaling may improve glycemic control in diabetes

Last updated July 18, 2026

Key finding

An 0.12 ± 0.08 increase of CD4+/CD8+ ratio was observed in SRP + OHI group when HbA1c ≥ 7.5%, which was significantly different to the control group (P = 0.040).

This study investigated the impact of subgingival scaling and root planing (SRP) combined with oral hygiene instruction (OHI) on glycemic control in type 2 diabetes patients with periodontitis, finding significant improvements in certain clinical measures.

Quick read

Study at a glance

The essential study design details in one scan.

EvidenceScore™

Moderate

Study type

RCTs

Follow-up

Medium-Term (3–12 mo)

Risk of bias

Some Concerns

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Plain-language summary

What this paper says

A plain-language read of the study’s main message and where it applies.

Study focus

Clinical relevance

Improving periodontal health is crucial for patients with diabetes, as it can influence overall health and glycemic control. This study highlights the potential benefits of dental interventions in managing diabetes-related complications, although further research is needed to clarify the relationship between periodontal treatment and glycemic control.

Keep in mind

The study's sample size may limit the generalizability of the findings. The lack of significant changes in HbA1c raises questions about the effectiveness of the interventions on glycemic control. The follow-up period of 6 months may not capture long-term effects.

Published in

Journal Reference

Publication details and source links for this paper.

Yadan F, Zhikai L, Lan C, Linhua G. The effect of subgingival scaling and root planing on glycemic control in patients with type 2 diabetes and periodontitis. BMC Oral Health. 2025;25:1065. doi:10.1186/s12903-025-06462-9

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Main Effects

SRP + OHI group showed a reduction in HbA1c of 0.22% compared to 0.07% in OHI group (P = 0.592).

CD4+/CD8+ ratio increased by 0.12 in SRP + OHI group when HbA1c ≥ 7.5% (P = 0.040).

BOP% significantly improved after treatment (P = 0.006).

Pocket depth significantly improved after treatment (P = 0.001).

Evidence network

How this study fits

Understand where this research contributes within the broader evidence network.

Evidence Context

This study contributes evidence to SRP + OHI and Bleeding on probing, Change in CD4+/CD8+ Ratio, Clinical attachment level, and 3 more.

This study contributes evidence to

Intervention

SRP + OHI

Outcome

Bleeding on probing

Evidence topic

HbA1c Reduction

Primary intervention

SRP + OHI

Primary outcomes

Bleeding on probing
Change in CD4+/CD8+ Ratio
Clinical attachment level

Evidence topics

HbA1c Reduction

Primary intervention

SRP + OHI

Primary outcomes

Bleeding on probing Change in CD4+/CD8+ Ratio Clinical attachment level

Evidence relationships

Intervention and outcome relationships this study adds to the evidence network.

Evidence pairs

Relationships

Evidence topics

contributes_evidence

Editorial context

Why this study matters

See why this paper is useful beyond its individual results.

Evidence network role

This section describes how the study fits into the current evidence network. It does not determine whether an intervention works on its own.

Moderate contributionModerate confidenceNetwork score: 63

Why it is useful

Contributes to 6 evidence relationships
Includes primary outcome data
Linked to 1 direct semantic evidence topic

Topic contributions

Evidence topic

Contributes evidence

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Primary evidence

Evidence topic

HbA1c Reduction

matched_outcome

Core evidence

Study findings

The primary outcomes reported in this study.

Bleeding on probing

SRP + OHI → Bleeding on probing

Evidence Intelligence™

EvidenceScore™: Strong; Score 79 · Based on 4 studies
ImpactScore™: 100; Very Positive
ConsistencyScore™: 100; consistent

Based on 4 studies

Add to Evidence Tracker

Change in CD4+/CD8+ Ratio

SRP + OHI → Change in CD4+/CD8+ Ratio

Evidence Intelligence™

EvidenceScore™: Emerging; Score 59 · Based on 1 study
ImpactScore™: 100; Very Positive
ConsistencyScore™: unclear; Not enough independent studies

Based on 1 study

Add to Evidence Tracker

Clinical attachment level

SRP + OHI → Clinical attachment level

Evidence Intelligence™

EvidenceScore™: 84; Strong
ImpactScore™: 83; Positive
ConsistencyScore™: 67; generally_consistent

Based on 6 studies

Add to Evidence Tracker

HbA1c

SRP + OHI → HbA1c

Evidence Intelligence™

EvidenceScore™: Strong; Score 79 · Based on 4 studies
ImpactScore™: 63; Slightly Positive
ConsistencyScore™: 35; mixed

Based on 4 studies

Add to Evidence Tracker

Periodontal probing depth

SRP + OHI → Periodontal probing depth

Evidence Intelligence™

EvidenceScore™: 83; Strong
ImpactScore™: 100; Very Positive
ConsistencyScore™: 100; consistent

Based on 7 studies

Add to Evidence Tracker

Plaque Index (PI)

SRP + OHI → Plaque Index (PI)

Evidence Intelligence™

EvidenceScore™: Strong; Score 79 · Based on 4 studies
ImpactScore™: 75; Positive
ConsistencyScore™: 35; mixed

Based on 4 studies

Add to Evidence Tracker

Evidence Library

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Evidence Suggest

SRP + OHI showed a 0.22% reduction in HbA1c, but not statistically significant.
Significant improvement in CD4+/CD8+ ratio with SRP + OHI (P = 0.040).
BOP% improved by 16.92% and pocket depth by 0.61 mm after treatment.

Who this applies to

Adults aged 30-65 with type 2 diabetes.
Patients diagnosed with periodontitis.

Keep in Mind

Results may not be applicable to populations outside the study demographics.
The study did not measure long-term effects beyond 6 months.
Further research is needed to establish a clear link between periodontal treatment and glycemic control.

Between the Lines

The study's sample size may limit the generalizability of the findings.
The lack of significant changes in HbA1c raises questions about the effectiveness of the interventions on glycemic control.
The follow-up period of 6 months may not capture long-term effects.

Evidence Library

Build your evidence library

Save research, organize studies, and quickly find important evidence again.

Connected Evidence

Explore related studies, evidence collections, and research questions.

Relationships organized using the Dediabetes Evidence Intelligence™ framework.

This study contributes to evidence on SRP + OHI and Clinical attachment level, SRP + OHI and Periodontal probing depth.

Related evidence relationships

Explore in Evidence Explorer

This study contributes to the evidence on the following intervention-outcome relationships.

Procedures

Detailed evidence

SRP + OHI → Clinical attachment level

Procedures

Evidence Intelligence™

EvidenceScore™: 84; Strong
ImpactScore™: 83; Positive
ConsistencyScore™: 67; generally_consistent

Based on 6 studies

View evidence

Procedures

Detailed evidence

SRP + OHI → Periodontal probing depth

Procedures

Evidence Intelligence™

EvidenceScore™: 83; Strong
ImpactScore™: 100; Very Positive
ConsistencyScore™: 100; consistent

Based on 7 studies

View evidence

Included in these evidence collections

Curated evidence collections and hubs this study is part of.

Periodontal probing depth Evidence Hub

All studies measuring Periodontal probing depth

7 studies

outcome_hub

Measures Periodontal probing depth as a key outcome.

Clinical attachment level Evidence Hub

All studies measuring Clinical attachment level

6 studies

outcome_hub

Measures Clinical attachment level as a key outcome.

SRP + OHI Evidence Hub

All studies on SRP + OHI

6 studies

intervention_hub

Contributes to SRP + OHI evidence base.

Recent Diabetes Research

Latest published studies

recency_collection

Published within the last 2 years.

Explore more in Evidence Explorer

Jump to pre-filtered views in Evidence Explorer.

All studies on SRP + OHI and Clinical attachment level

Intervention: SRP + OHIOutcome: Clinical attachment level

6 results

All studies on SRP + OHI and Periodontal probing depth

Intervention: SRP + OHIOutcome: Periodontal probing depth

7 results

All studies on SRP + OHI

Intervention: SRP + OHI

6 results

All studies measuring Clinical attachment level

Outcome: Clinical attachment level

6 results

All studies measuring Periodontal probing depth

Outcome: Periodontal probing depth

7 results

Questions answered by this study

Generated from the study's connected evidence using Evidence Intelligence™.

Does SRP + OHI improve clinical attachment level?

Strong Evidence

SRP + OHI may improve Clinical attachment level.

ConsistencyScore™: Results are generally consistent across studies.

Ranked evidence signals

1
Clinical attachment level
EvidenceScore™ Strong | EvidenceScore™ 83.6 | moderate positive | ConsistencyScore™ Generally Consistent | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

Only one supporting study is available.
Population details are unavailable.

View Full Evidence

Does SRP + OHI improve periodontal probing depth?

Strong Evidence

SRP + OHI appears to improve Periodontal probing depth.

ConsistencyScore™: Results are consistent across studies.

Ranked evidence signals

1
Periodontal probing depth
EvidenceScore™ Strong | EvidenceScore™ 83.5 | strong positive | ConsistencyScore™ Consistent | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

Only one supporting study is available.
Population details are unavailable.

View Full Evidence

Does SRP + OHI improve bleeding on probing?

Strong Evidence

SRP + OHI appears to improve Bleeding on probing.

ConsistencyScore™: Results are consistent across studies.

Ranked evidence signals

1
Bleeding on probing
EvidenceScore™ Strong | EvidenceScore™ 79.0 | strong positive | ConsistencyScore™ Consistent | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

Only one supporting study is available.
Population details are unavailable.

View Full Evidence

Does SRP + OHI improve plaque index (pi)?

Strong Evidence

SRP + OHI may improve Plaque Index (PI).

ConsistencyScore™: Results are mixed and should be interpreted cautiously.

Evidence caveat: The available evidence reports mixed findings.

Ranked evidence signals

1
Plaque Index (PI)
EvidenceScore™ Strong | EvidenceScore™ 79.0 | moderate positive | ConsistencyScore™ Mixed | 1 study

Why this answer: This answer is cautious because the available studies report mixed findings.

Limitations

Only one supporting study is available.
Population details are unavailable.

View Full Evidence

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Next steps

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Evidence topics

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HbA1c Reduction Evidence Hub

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All studies on SRP + OHI and HbA1c All studies on SRP + OHI and Clinical attachment level All studies on SRP + OHI and Periodontal probing depth All studies on SRP + OHI and Bleeding on probing

Related research

Read related research summaries.

Scaling and root planing improves glycemic control in T2DM Additional toothbrushing improves oral health in type 2 diabetes patients NSPT improves plaque index and glycemic control in diabetes.Adjunctive therapy improves periodontal outcomes in diabetes patients Coenzyme Q10 improves periodontal health in diabetic patients

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