Objectives:  The aim of this pilot study was to assess the role of SDD (subantimicrobial dose doxycycline) as an adjunct to scaling and root planing (SRP) in the treatment of moderate-severe chronic periodontitis (CP) in elderly patients 65 years and older. 

Methods:  A double-blind, randomized, placebo-controlled study was conducted to test the efficacy of SDD (20mg doxycycline BID) in combination with SRP in an institutionalized geriatric population with CP.  Twenty-four patients, aged 65 years and older, with evidence of CP manifested by baseline clinical attachment levels (CAL) 5-9mm, probing depths (PD) 4-9mm and bleeding on probing were enrolled.  At baseline, patients were treated by a standardized episode of SRP, and randomized to receive either adjunctive SDD or placebo.  Full mouth PD were measured using the manual UNC-15 periodontal probe at 3, 6, and 9 months post-baseline to assess the response to treatment.  Tooth sites were stratified by baseline PD value:  sites with PD 4-6mm were considered mild-moderately diseased and sites with PD ≥ 7mm severely diseased.  Treatment group comparisons of per-patient mean PD changes were performed using appropriate analysis of variance models.

Results:  SRP+placebo resulted in PD reductions similar to those reported previously in the literature.  At all time points and in all tooth site categories, SRP+SDD resulted in significantly greater PD reductions relative to baseline than SRP+placebo:

Baseline PD value	Visit	SRP+SDD	SRP+Placebo	P
4-6 mm	Month 3	1.69	0.69	< 0.05
	Month 6	1.51	0.73	< 0.05
	Month 9	1.64	0.69	< 0.05
≥ 7 mm	Month 3	3.00	0.68	< 0.05
	Month 6	3.90	0.64	< 0.05
	Month 9	4.34	0.70	< 0.05

Conclusions:  SDD when used as an adjunct to SRP provides superior benefit for elderly CP patients compared to SRP alone. 

Supported by a grant from CollaGenex Pharmaceuticals, Inc.