Systemic Doxycycline as an Adjunct to Scaling and Root Planing in Diabetic Patients With Periodontitis

A Systematic Review and Meta-analysis

Kenneth Chou Hung Yap; Shaju Jacob Pulikkotil


BMC Oral Health. 2019;19(209) 

In This Article


The electronic search retrieved 1358 records. No other additional records were identified through other sources. After removing the duplicates, there were 1110 records remaining, of which 1078 of them did not meet the inclusion criteria. After that, 32 of the remaining articles were assessed for eligibility. From these 32 studies, 26 of the studies did not meet the inclusion criteria and 6 of the studies were included in the meta-analyses. Figure 1 shows the studies that have been found with duplicates removed, screened and assessed for eligibility. An in-depth analyses of all studies showed low-to-moderate heterogeneity [(BOP: P = 0.30, I2 = 8% (Figure 2); CAL: P = 0.17, I2 = 36% (Figure 3); HbA1c: P = 0.39, I2 = 3% (Figure 4); PD: P = 0.09, I2 = 48% (Figure 5)]. All 6 studies had adequate data for the statistical analysis of CAL gain and HbA1c reduction at 3 months but insufficient data at 6 months and above. Total number of patients included are 276 at 3 months. Forest plots of primary and secondary data outcomes are given in Figs. 2, 3, 4 and 5. Meta-analysis showed no statistically significant improvement in CAL at 3 months (SMD -0.22; − 0.52, 0.08) and HbA1c levels at 3 months (SMD -0.13; − 0.41, 0.15) when systemic doxycycline is used as an adjunct to scaling and root planing compared to just SRP alone. It is the same case in PD (SMD -0.16;-0.50, 0.18) and BOP (SMD -0.27; − 0.80, 0.27) where there is no significant improvement when systemic doxycycline is used as an adjunct to scaling and root planing compared to just SRP alone after 3 months. This shows that there is no difference in effectiveness of systemic doxycycline as compared to control group.

Figure 1.

PRISMA flow chart

Figure 2.

3 Month bleeding on probing (BOP)

Figure 3.

3 Month clinical attachment levels (CAL)

Figure 4.

3 Month glycated hemoglobin (HbA1c)

Figure 5.

3 month probing depth (PD)

Figure 6 provides information about the risk of bias of the studies that are included. From the tabled data, none of the 6 studies taken had a low risk of bias in any of the domains that were assessed. All 6 studies were reviewed by each of the reviewers independently and came up with the conclusion that only 2 out of 6 of the studies taken are at a high risk of bias, mainly Gaikwad 2013 and Al-Zahrani 2009.

Figure 6.

Assessment of risk of bias. Green: low risk of bias, Yellow: Moderate risk of bias, Red: High risk of bias

Figure 7 shows GRADE Working Criteria which is used to assess the standard of the scientific research in systematic reviews.[12] Risk of bias of HbA1c levels and CAL data after 3 months was found to be serious due to the lack of information regarding allocation concealment in all 6 of the studies that were reviewed.

Figure 7.

GRADE working criteria

The general characteristics of all the 6 studies are shown in Table 1. Some of the studies used different dose and duration of dose given to the patient.