Table 5.
Results from fitting a linear multilevel regression model for changes in treatment effect over time on CAL in sites that had a baseline probing depth of at least 5 mm using the restricted maximum likelihood estimation (REML)
| Therapy | 3 months estimate 95% (CI) | 6 months estimate 95%(CI) | 12 months estimate (SE) | 18 months estimate (SE) | 24 months estimate (SE) |
|---|---|---|---|---|---|
| SURG+AMOX+MET | 0.11 (−0.12, 0.33) | 0.04 (−0.19, 0.26) | −0.05 (−0.27, 0.17) | −0.21 (−0.43, 0.01) | −0.21 (−0.43, 0.01) |
| SURG+TET | 0.32 (0.12, 0.53)* | −0.03 (−0.24, 0.18) | 0.03 (−0.18, 0.23) | −0.04 (−0.26, 0.16) | −0.10 (−0.30, 0.12) |
| SURG | 0.49 (0.29, 0.69)* | 0.48 (0.28, 0.68)* | 0.61 (0.40, 0.80)* | 0.44 (0.25, 0.66)* | 0.40 (0.20, 0.60)* |
| AMOX+MET+TET | −0.01 (−0.36, 0.09) | −0.39 (−0.58, −0.21)* | −0.47 (−0.67, −0.28)* | −0.52 (−0.70, −0.32)* | −0.54 (−0.73, −0.34)* |
| AMOX+MET | −0.14 (−0.36, 0.09) | −0.51 (−0.74, −0.30)* | −0.55 (−0.77, −0.33)* | −0.63 (−0.84, −0.40)* | −0.67 (−0.90, −0.45)* |
| TET | 0.07 (−0.12, 0.27) | −0.05 (−0.25, 0.14) | 0.03 (−0.18, 0.22) | −0.27 (−0.46, −0.08)* | −0.25 (−0.45, −0.06)* |
| SURG+MET+AMOX+TET | −0.05 (−0.27, 0.16) | −0.27 (−0.48, −0.07)* | −0.22 (−0.43, −0.01)* | −0.27 (−0.48, −0.07)* | −0.38 (−0.60, −0.18)* |
Patient sites that had been surgically treated only experienced significant CAL loss over time. These sites had a mean CAL loss of 0.49 mm after 3 months and a mean CAL loss of 0.40 mm after 24 months compared to SRP. However, significant reversal in CAL loss was observed over time when SURG was combined with MET, AMOX and TET. For example, SURG+MET+AMOX+TET had a significant mean CAL gain of 0.27 mm after 6 months, 0.22 mm after 12 months, 0.27 mm after 18 months and 0.38 mm after 24 months compared to SRP at baseline conditions. On the other hand, sites that were treated with antibiotics only also had reversals in CAL when compared to SRP over time. AMOX+MET resulted in a mean CAL gain of 0.14 mm after 3 months, 0.51 mm after 6 months, 0.55 mm after 12 months, 0.63 mm after 18 months, and 0.67 mm after 24 months compared to SRP at baseline conditions.
All therapies were compared to SRP. Other fixed effects of the model are given in Table 3.
*Significant results at 0.05 when compared to SRP at baseline visit. Negative estimates from the model results imply that there was CAL gain and positive estimates represent further CAL loss.