Background:Clinical standardization and calibration training is recommended to increase the reproducibility of periodontal probing, but its impact on manual periodontal probing outcomes has received little attention. This study examined the reproducibility of manual periodontal probing performed by a periodontist after completion of a comprehensive standardization and calibration training program.Methods:A newly-educated periodontist was subjected to an individualized periodontal probing standardization and calibration training program involving approximately 24 total hours of lecture, bench-top, and clinical instruction/evaluation. Satisfactory completion of each portion of the training program required ≥ 95% intra-examiner agreement within 1 mm between initial and repeat measurements, and a ≥ 90% level of exact agreement with measurements by a "gold standard" examiner. The periodontist then evaluated bleeding on probing (BOP) and performed duplicate measurements of probing depth (PD) and the distance between the cementoenamel junction and gingival margin (CEJ-GM) with a manual periodontal probe on 567 periodontal sites exhibiting ≥ 5 mm PD with BOP in 39 adults. Clinical periodontal attachment level (CAL) was calculated for each site as (PD) - (CEJ-GM).Results:Intra-examiner measurement error (the standard deviation for a single measurement) was found to be 0.21 mm for PD, 0.15 mm for CEJ-GM, and 0.26 mm for CAL. Replicate assessments of PD and CAL yielded excellent exact agreement kappa scores of 0.86 and 0.87, respectively. Greater intra-examiner measurement error was found at periodontal sites with more gingival inflammation as measured by higher BOP index scores.Conclusion:These findings demonstrate that a rigorous periodontal probing standardization and calibration training program facilitates acquisition of highly reproducible PD and CAL assessments in moderate to deep inflamed periodontal pockets with a manual periodontal probe. Similar formal hands-on training should be incorporated into dental education programs and clinical research studies to improve the diagnostic performance of manual periodontal probing of the periodontium.

OBJECTIVE:The objective was to evaluate the effects of an 8.5% sustained-release doxycycline-containing polymer formulation (SRDF) on deep pockets (pocket depth [PD] ≥ 7 mm) in chronic periodontitis. Total bacterial counts were used to estimate the number of viable bacteria present before treatment and for up to 6 months posttreatment. METHODS:All sites had PD ≥ 5 mm and bled on probing in 23 subjects who received treatment with SRDF. There was an average of 8.7 teeth or 23 sites for each subject. One deep pocket (≥ 7 mm) in each subject was selected for monitoring. This site was sampled prior to treatment and at 7, 21, 91, and 182 days after SRDF placement. The primary endpoints were changes in the viable counts of two red complex species, Porphyromonas gingivalis and Tannerella forsythia. Secondary endpoints were changes in the number of total anaerobic bacteria recovered and changes in PD. RESULTS:Relative to baseline, SRDF reduced the proportions of P. gingivalis and T. forsythia by 88% and 99%, respectively, at day 7. At the conclusion of the monitoring period--182 days--P. gingivalis and T. forsythia were present but at 19% to 20% of the pretreatment values. Total anaerobic counts were reduced by 96% at day 7; by 87% at day 21; and by 75% and 68% at days 91 and 182, respectively. Mean PD for the sample sites (initially ≥ 7 mm) was reduced 2 mm by day 21, and this difference persisted throughout the study. CONCLUSIONS:This study demonstrates SRDF has a significant effect, not only statistically but also microbially and clinically, on deep periodontal sites in patients with chronic periodontitis. SRDF significantly reduced the number of red complex bacteria P. gingivalis and T. forsythia, as well as the number of total anaerobic bacteria. By day 21, PD was reduced by 2 mm, and this reduction was maintained for at least 6 months posttherapy.

Proof-of-concept efforts to demonstrate the propulsion capabilities of microcavity plasma discharges through design and fabrication of a Microcavity Discharge (MCD) thruster are discussed. The primary goal is to design and fabricate a MCD thruster and to demonstrate that the MCD thruster can ultimately achieve performance levels of 1 mN per cavity, a thrust efficiency exceeding 60%, and an Isp of 160 seconds. Because the MCD thruster has low specific mass and is scalable over a large number of cavities, a successful performance demonstration would ultimately result in an advanced propulsion system useful for primary (orbit transfer, maneuvering) and secondary (attitude, position and acceleration control) applications for a wide range of satellites. Research at the University of Illinois (Optical Physics and Engineering, Electric Propulsion labs) and the University of Texas at Austin (Computational Plasma Research Lab) is described. Microcavity electrode arrays with integral micronozzles on each cavity are fabricated and are driven at 20 - 150 kHz at a power level of up to 0.25 W per cavity. Thruster and mass flow measurements are made with cold flow to determine nozzle performance. Heating measurements are made to determine stagnation temperature and heat loss. Computational modeling provides a simulation-based understanding of the plasma physics in the microcavity and supports the experimental measurements. A detailed first-principles computational model provides time-accurate solutions of the multi-species, multi-temperature, self-consistent plasma governing equations for discharge physics, coupled to the compressible Navier-Stokes equations for the bulk fluid flow through the MCD thruster.

Objectives: To assess the environmental knowledge of college nutrition students in regards to: Global Warming, Genetically Modified Organisms (GMOs), Sustainable Food Systems, and United States (U.S.) Organic Standards. Methods: 72 college nutrition students, juniors and seniors completed a self-administered survey of demographics and environmental knowledge at the beginning and at the end of the school year. Mann-Whitney U Test and Fisher's Exact Test were used and significance was determined by a p< 0.05. Results: The overall environmental knowledge among college nutrition students was low. Overall knowledge comparing juniors at the beginning of the school year to seniors at the end of the school year was statistically significantly higher (p < 0.005). When comparing Juniors-Beginning to Seniors-Ending, there was statistically significant increase in environmental knowledge in the GMOs (p< 0.027), Sustainable Food Systems (p< 0.027), and Organic Standards (p< 0.031) sections. Conclusions: Environmental knowledge among college nutrition students was low. Based on our findings, more emphasis should be placed on promoting environmental knowledge in college curriculums. Name of the department and institution or hospital where the work was done: Bastyr University. The source of any support received: This research was supported in part by Bastyr University.

Aim: The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy.Methods: Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox(TM), Elyzol(R) Dental Gel or PerioChip(R) at all residual periodontal pockets with a probing depth greater than or equal to 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol(R) Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters.Results: Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol(R) Dental Gel [0.03 mm +/- 0.09 (SD)](p=0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip(R) application did not differ significantly from that obtained following the application of Atridox(TM) (p=0.27). Of the sites treated with Atridox(TM) , 42% gained greater than or equal to 1 mm PAL and 9% greater than or equal to 2 mm PAL as opposed to the sites treated with Elyzol(R) Dental Gel, in which 34% gained greater than or equal to 1 mm PAL and 8% gained greater than or equal to 2 mm PAL. Of the sites treated with PerioChip(R), 36% gained greater than or equal to 1 mm and 6% gained greater than or equal to 2 mm PAL following a completed initial periodontal therapy.Conclusions: The application of the three biodegradable sustained release devices tested following initial periodontal therapy resulted in a statistically significant gain in mean PAL for Atridox(TM) and a significant reduction in PPD for all three devices during the study period. Furthermore, when sites treated with Atridox(TM) were compared with sites treated with Elyzol(R) , a significant difference in mean PAL gain (0.3 mm) was observed.

Aim: The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy.Methods: Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox(TM), Elyzol(R) Dental Gel or PerioChip(R) at all residual periodontal pockets with a probing depth greater than or equal to 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol(R) Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters.Results: Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol(R) Dental Gel [0.03 mm +/- 0.09 (SD)](p=0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip(R) application did not differ significantly from that obtained following the application of Atridox(TM) (p=0.27). Of the sites treated with Atridox(TM) , 42% gained greater than or equal to 1 mm PAL and 9% greater than or equal to 2 mm PAL as opposed to the sites treated with Elyzol(R) Dental Gel, in which 34% gained greater than or equal to 1 mm PAL and 8% gained greater than or equal to 2 mm PAL. Of the sites treated with PerioChip(R), 36% gained greater than or equal to 1 mm and 6% gained greater than or equal to 2 mm PAL following a completed initial periodontal therapy.Conclusions: The application of the three biodegradable sustained release devices tested following initial periodontal therapy resulted in a statistically significant gain in mean PAL for Atridox(TM) and a significant reduction in PPD for all three devices during the study period. Furthermore, when sites treated with Atridox(TM) were compared with sites treated with Elyzol(R) , a significant difference in mean PAL gain (0.3 mm) was observed.

Background, aim: The effect of subgingival calculus on the clinical outcomes of the local delivery of antimicrobials is unknown, This study examines the clinical outcomes of treatment with locally delivered controlled-release doxycycline (DH) or scaling and root planing (SRP) in subsets of adult periodontitis patients with known baseline levels of subgingival calculus.Methods: The data examined were obtained from 393 patients who participated in 2 multi-center trials. All patients had baseline subgingival calculus levels assessed and were then treated at baseline and month 4 with either DH or SRP Clinical attachment levels (CAL), pocket depth (PD) and bleeding on probing (BOP) were assessed at baseline and months 1, 2, 4, 5, 6, 8 and 9.Results: Treatment with either DH or SRP resulted in significant statistical and clinical improvements in CAL, PD and BOP. These clinical outcomes were equivalent regardless of the extent of subgingival calculus present at baseline.Conclusions: The results indicate that the primary clinical effects of these therapies are the result of a disruption and reduction of the subgingival plaque and not the effect of the removal of subgingival calculus and contaminated cementum.

AIM:In the present 6-month multicentre trial, the outcome of 2 different approaches to non-surgical treatment of chronic periodontitis, both involving the use of a locally delivered controlled-release doxycycline, was evaluated. MATERIAL AND METHODS:105 adult patients with moderately advanced chronic periodontitis from 3 centres participated in the trial. Each patient had to present with at least 8 periodontal sites in 2 jaw quadrants with a probing pocket depth (PPD) of > or =5 mm and bleeding following pocket probing (BoP), out of which at least 2 sites had to be > or =7 mm and a further 2 sites > or =6 mm. Following a baseline examination, including assessments of plaque, PPD, clinical attachment level (CAL) and BoP, careful instruction in oral hygiene was given. The patients were then randomly assigned to one of two treatment groups: scaling/root planing (SRP) with local analgesia or debridement (supra- and subgingival ultrasonic instrumentation without analgesia). The "SRP" group received a single episode of full-mouth supra-/subgingival scaling and root planing under local analgesia. In addition, at a 3-month recall visit, a full-mouth supra-/subgingival debridement using ultrasonic instrumentation was provided. This was followed by subgingival application of an 8.5% w/w doxycycline polymer at sites with a remaining PPD of > or =5 mm. The patients of the "debridement" group were initially subjected to a 45-minute full-mouth debridement with the use of an ultrasonic instrument and without administration of local analgesia, and followed by application of doxycycline in sites with a PPD of > or =5 mm. At month 3, sites with a remaining PPD of > or =5 mm were subjected to scaling and root planing. Clinical re-examinations were performed at 3 and 6 months. RESULTS:At 3 months, the proportion of sites showing PPD of < or =4 mm was significantly higher in the "debridement" group than in the "SRP" group (58% versus 50%; p<0.05). The CAL gain at 3 months amounted to 0.8 mm in the "debridement" group and 0.5 mm in the "SRP" group (p=0.064). The proportion of sites demonstrating a clinically significant CAL gain (> or =2 mm) was higher in the "debridement" group than in the "SRP" group (38% versus 30%; p<0.05). At the 6-month examination, no statistically significant differences in PPD or CAL were found between the two treatment groups. BoP was significantly lower for the "debridement" group than for the "SRP" group (p<0.001) both at 3- and 6 months. The mean total treatment time (baseline and 3-month) for the "SRP" patients was 3:11 h, compared to 2:00 h for the patients in the "debridement" group (p<0.001). CONCLUSION:The results indicate that simplified subgingival instrumentation combined with local application of doxycycline in deep periodontal sites can be considered as a justified approach for non-surgical treatment of chronic periodontitis.

Field gleaning, or harvesting crops after the commercial harvest, has been promoted as a way to increase food security; however, the effectiveness of gleaning programs is not well documented. The purpose of this research was to explore the impact of gleaning on individual gleaners and the community by documenting total amounts gleaned, individual uses of produce, and self-reported benefits and barriers to gleaning. During the 1997 season, ~50 gleaners participated in the Pierce County Expanded Food and Nutrition Education Program Gleaning Project; 29 participated in an intensive 4-week study to track use of produce by gleaners. Onsite weighing of gleaned produce revealed that of the 110,000 pounds gleaned by these 50 gleaners from Pierce County farms and orchards during 1997, 85,000 pounds (77%) were donated to local emergency food programs; 25,000 pounds (23%) were taken home by gleaners. Of the produce taken home by the 29 study participants, an estimated 9% was used fresh, 48% was preserved for later user, and 43% was shared with others. During a combination of telephone and in-person interviews, gleaners reported using more fresh produce and sharing knowledge about gardening and food preservation. The most important benefits of gleaning were "stretching my food budget" and "helping provide food for the community." Detailed exploration of the impact of gleaned produce on dietary patterns and use of validated food security measures is warranted considering the volume of produce used fresh, preserved for later use, and given away by gleaning participants.

AIM The purpose of this retrospective analysis was to examine what effect, if any, the time elapsed between an individual's last episode of scaling and root planing and subsequent treatment with a sustained-release doxycycline hyclate gel (DH) alone or scaling and root planing alone (SRP) would have upon adult periodontitis. METHODS A total of 207 subjects were included in the DH group and 210 patients in the SRP group. Periodontitis was defined as those sites which presented with pocket depths > or =5 mm and exhibited bleeding upon probing. In both DH and SRP groups, 3 sub-groups of subjects were identified according to their last episode of scaling and root planing prior to the study baseline: within 2 to 6 months, >6 but < or =12 months, and one or more times in their life but not within the last 12 months. Each study site was treated twice over a 9-month study period, once at baseline and again at 4 months. Data from the study sites at 4, 6, and 9 months were then evaluated for changes in probing depth, clinical attachment level, and bleeding upon probing. RESULTS At the 9-month evaluation, all sub-groups in the DH and SRP treatment arms presented with improvement in the measured clinical parameters, as compared to baseline. No significant differences were observed in the measured periodontal indices among the study sites between the three sub-groups for either treatment. CONCLUSIONS It is concluded that the time interval since the last episode of scaling and root planing had no observable effect on the results achieved when treating periodontitis sites with locally delivered doxycycline hyclate alone or scaling and root planing alone. The treatment of periodontitis sites with locally delivered doxycycline hyclate resulted in clinical improvement comparable to scaling and root planing irrespective of the patient's prophylaxis frequency.

This case report describes human histologic data of periodontal regeneration following guided tissue regeneration therapy (GTR) with a bioabsorbable barrier composed of polylactic acid. The tooth that was examined was part of a previously published study of the clinical effects of GTR therapy without the use of bone or bone substitutes on Class II furcation defects. Twenty-five months following the surgical procedure, the tooth was extracted for non-periodontal reasons. During this extraction, the bone within the furcation that was treated in the study was luxated with the tooth. At the completion of the study (month 12), the furcation's vertical probing depth had decreased by 2 mm with a 2 mm gain in clinical attachment. The horizontal furcation measurement decreased by 3 mm. Following extraction, the tooth was prepared for light microscopy and sectioned in the mesial-distal plane. Reference notches were not placed in the tooth at the time of surgery as there were no plans to perform histologic analysis in the study. However, using the buccal root prominences and what we interpreted to be root planing marks on the cementum, we were able to demonstrate that complete periodontal regeneration occurred on the root surface that was exposed to the pocket environment prior to surgery. New alveolar bone, cementum, and periodontal ligament were consistently observed throughout the furcation in the areas that demonstrated clinical attachment gain and a decrease in horizontal probing depth. This case report adds to the accumulating evidence of histologic periodontal regeneration following guided tissue regeneration with bioabsorbable polylactic acid barriers.

Background: The purpose of this study was to determine the effects of periodontal treatment with a sustained‐release, biodegradable gel containing 8.5% doxycycline on the anaerobic flora and on antibiotic susceptibility patterns associated with subgingival plaque and saliva.Methods: Forty‐five subjects with adult periodontitis were entered into a parallel design, single‐blind study of 6 months' duration. The subjects were randomized to receive either doxycycline treatment (n = 23) or oral hygiene instruction/reinforcement (n = 22). Saliva and subgingival plaque samples were collected prior to and at 7, 21, 91, and 182 days after initiation of treatment. The proportion of the cultivable flora resistant to 10 µg doxycycline/ml was determined relative to total anaerobic counts, and the 3 most predominant colony types resistant to doxycycline were individually enumerated. A representative of each was subcultured, identified to genus and species level, and tested for its susceptibilities to 6 antibiotics.Results: A significant decrease (P <0.01) in total anaerobic counts following doxycycline treatment caused a transient increase in the proportion, but not in the actual counts, of doxycycline‐resistant bacteria recovered from both plaque and saliva at 7 and 21 days but not at 91 or 182 days. The same doxycycline‐resistant taxa were recovered at all sample periods including baseline. Regardless of treatment, the isolates were similarly distributed and belonged to the same bacterial groups.Conclusions: Doxycycline treatment significantly reduced the anaerobic population in plaque but did not result in a change in either the number of resistant bacteria present or the acquisition of antibiotic resistance. J Periodontol 2000;71:768‐774.

BACKGROUND This research report evaluates clinical changes resulting from local delivery of doxycycline hyclate (DH) or traditional scaling and root planing (SRP) in a group of patients undergoing supportive periodontal therapy (SPT). METHODS In all, 141 patients received either DH (67) or SRP (74) treatment in sites > or =5 mm on one-half of their dentition at baseline and month 4. RESULTS Clinical results were determined at month 9. Baseline mean probing depth recordings were similar between the two groups (DH = 5.9 mm; SRP = 5.9 mm). Mean month 9 results showed similar clinical results for attachment level gain (DH 0.7 mm; SRP 0.8 mm) and probing depth reduction (DH 1.3 mm; SRP 1.1 mm). Percentage of sites showing > or =2 mm attachment level gain at month 9 was 24.7% in the DH group and 21.2% in the SRP group. Thirty-nine percent (39%) of DH sites and 38% of SRP sites showed > or =2 mm probing depth reduction. When treated sides of the dentition were compared to untreated sides, DH showed a difference in disease activity (> or =2 mm attachment loss) from 19.3% (untreated) to 7.2% (treated); and SRP from 14.3% (untreated) to 8.1% (treated). CONCLUSIONS Results show that both DH without concomitant mechanical instrumentation and SRP were equally effective as SPT in this patient group over the 9-month study period.

This article describes preliminary in vivo studies evaluating the osteogeneic potential of bone morphogenetic proteins (BMPs) delivered from an absorbable puttylike polymer matrix. In the first study, bovine-derived bone morphogenetic proteins were incorporated in an polymer matrix consisting of 50:50 poly(DL-lactide-co-glycolide) dissolved in N-methyl-2-pyrrolidone. The matrix was implanted in an 8 mm critical-size calvarial defect created in the skull of adult Sprague-Dawley rats (n = 5 per treatment group). After 28 days, the implant sites were removed and examined for new bone formation, polymer degradation, and tissue reaction. Gamma-irradiated polymer matrices appeared to give more bone formation than nonirradiated samples (histological analysis; 2. 76 + 1.34 mm(2) of bone versus 1.30 + 0.90 mm(2) of bone, respectively and x-ray analysis; 27.2 + 15.9 mm(2) of bone versus 20. 7 + 16.7 mm(2) of bone, respectively) and less residual polymer (0.0 + 0.0 versus 0.2 + 0.4, respectively). The polymer implants with bone morphogenetic protein also gave less inflammatory response than the polymer controls (gamma irradiated polymer/BMP = 1.8 + 0.4 and nonirradiated polymer/BMP = 1.2 + 0.4 versus polymer only = 3.0 + 1. 2, respectively). However, despite trends in both the x-ray and histological data there was no statistical difference in the amount of new bone formed among the four treatment groups (P > 0.05). This was most likely due to the large variance in the data scatter and the small number of animals per group. In the second animal study, bovine-derived BMPs and the polymeric carrier were gamma irradiated separately, at doses of 1.5 or 2.5 Mrad, and their ability to form bone in a rat skull onlay model was evaluated using Sprague-Dawley rats (n = 5 per treatment group). Histomorphometry of skull caps harvested 28 days after implantation showed no significant differences as compared to non-irradiated samples, in implant area, new bone area, and percent new bone (P > 0.05). These results suggest gamma irradiation may be useful in sterilization of the bovine-derived BMPs and the polymeric carrier for potential bone repair and/or regeneration applications.

This paper examines the effects of smoking on the treatment outcomes of two nonsurgical therapies: (1) scaling and root planing alone (SRP) or (2) controlled-release of subgingivally delivered doxycycline hyclate in a polylactic acid based polymer gel. Subjects from 2 9-month multicenter studies were classified as nonsmokers (never smoked: 100 subjects), former smokers (137 subjects), and current smokers (> or = 10 cigarettes/day: 121 subjects). Clinical parameters were analyzed for treated sites with baseline probing depths > or = 5 mm and for a subset of treated sites with baseline probing depths of > or = 7 mm. Clinical parameters (plaque levels, clinical attachment levels, pocket depths, and bleeding on probing) were analyzed at baseline, 4, 6, and 9 months. In the doxycycline treated group in general, there were neither marked significant differences in clinical attachment gain nor differences in probing depth reduction among the 3 smoking groups. On the other hand, in the scaling and root planing treated group in general, there were significant differences in clinical attachment gain and pocket depth reduction, with non-smokers responding better than former smokers and current smokers at 6 and 9 months. These differences in clinical response between scaling and root planing alone versus controlled-release of locally-delivered doxycycline hyclate among these 3 smoking groups are discussed in relation to treatment implications for smokers.

Background: The clinical efficacy and safety of doxycycline hyclate (8.5% w/w) delivered subgingivally in a biodegradable polymer (DH) was compared to placebo control (VC), oral hygiene (OH), and scaling and root planing (SRP) in 2 multi‐center studies.Methods: Each study entered 411 patients who demonstrated moderate to severe periodontitis. Patients had 2 or more quadrants each with a minimum of 4 qualifying pockets ≥5 mm that bled on probing. At least 2 of the pockets were ≥7 mm. Treatment with DH, VC, OH, or SRP was provided at baseline and again at month 4. Clinical parameters were recorded monthly.Results: DH and SRP resulted in nearly identical clinical changes over time in both studies. Mean 9 month clinical attachment level gain (ALG) was 0.8 mm for the DH group and 0.7 mm for the SRP group in Study 1, and 0.8 mm (DH) and 0.9 mm (SRP) in Study 2. Mean probing depth (PD) reduction was 1.1 mm for the DH group and 0.9 mm for the SRP group in Study 1 and 1.3 mm for both groups in Study 2. Frequency distributions showed an ALG ≥2 mm in 29% of DH sites versus 27% of SRP sites in Study 1 and 31% of DH sites versus 34% of SRP sites in Study 2. PD reductions ≥2 mm were seen in 32% of DH sites versus 31% of SRP sites in Study 1 and 41% of DH sites versus 43% of SRP sites in Study 2. Comparisons between DH, VC, and OH treatment groups showed DH treatment to be statistically superior to VC and OH. Safety data demonstrated a benign safety profile with use of the DH product.Conclusions: Results of this trial demonstrate that treatment of periodontitis with subgingivally delivered doxycycline in a biodegradable polymer is equally effective as scaling and root planing and superior in effect to placebo control and oral hygiene in reducing the clinical signs of adult periodontitis over a 9‐month period. This represents positive changes resulting from the use of subgingivally applied doxycycline as scaling and root planing was not limited regarding time of the procedure or use of local anesthesia. J Periodontol 1999;70:490‐503.