Biomedical subjects

D van Steenberghe

Publications and source records attributed to D van Steenberghe.

At least 55 records · Page 3Linked to original sources

PubMed2000

Sensations and trigeminal somatosensory-evoked potentials elicited by electrical stimulation of endosseous oral implants in humans.

The perception of bipolar electrical stimuli through implants was studied. The stimuli were delivered to permucosal oral endosseous implants in 15 individuals, who then reported tapping to beating sensations. In 10 out of the 15, these stimuli evoked clearly distinguishable potentials in the averaged electroencephalograms. The most prominent scalp potential was a positive wave with a latency between 18 and 25 ms, often preceded by a negative wave with a latency around 12-17 ms. In contrast, when a motor response was elicited by stimulation of the lip, a shorter latency wave around 8-11 ms was found additionally, indicating that the former-mentioned waves represent a true sensory response and not an artefact of myogenous origin. Furthermore, topical anaesthesia of the gingiva surrounding the implants in six individuals had little effect on the sensory responses. This evidence excluded peri-implant mucosal innervation as the origin of the perception and of the somatosensory-evoked waves elicited by the electrical stimulation of the oral implants. To the best of our knowledge, for the first time a sensation (osseoperception) has been elicited by electrical stimulation of endosseous oral implants and correlated with simultaneously recorded trigeminal somatosensory-evoked potentials (TSEPs).

Adult↗

PubMed2000

A prospective split-mouth comparative study of two screw-shaped self-tapping pure titanium implant systems.

Clinical data indicate different medium and long-term outcomes of endosseous implants for different implant configurations and in particular implant surfaces. The present study compares 2 very similar implant systems but with different surface characteristics in a split-mouth-randomized design. The Astra-Tech (A) system (Astra-Tech AB, Mölndal, Sweden) consisted of selftapping TiO2-blasted screw-shaped implants made of commercially pure titanium, and the Brånemark (B) System (Nobel Biocare, Gothenburg, Sweden) comprised selftapping Mark II implants with machined surface irregularities. Throughout the 2-years' observation period, no significant differences could be found concerning probing depths, presence of plaque or change in marginal bone level. A statistically significant difference in location of the marginal bone level in relation to the shoulder of the implant was found in favor of the A system both at baseline and after 2 years. Cumulative success rates of 100% (A) and 97.7% (B) were not statistically different. From a prosthetic point of view, more soldering points were needed for A compared to B to reach clinical acceptable fit. More years of observation are needed to compare the fate of the soft and hard tissues surrounding two different implant surfaces.

Adult↗

PubMed2000

The clinical use of deproteinized bovine bone mineral on bone regeneration in conjunction with immediate implant installation.

Twenty-one c.p. titanium screw-shaped implants were immediately installed after extraction and thorough curettage of the alveoli in 15 patients. Granules of deproteinized bovine bone of 0.25-1.0 mm diameter were used to fill the remaining defect when the distance of the defect wall to the implant surface was > 3 mm. Dimensional measurements of the defect height and width were made with a pocket probe. Fourteen sites in the upper jaw and 7 sites in the lower jaw were thus treated. The mean defect depth varied between 7 mm vestibularly and 10 mm mesially. The mucoperiosteal flaps were hermetically closed. At re-entry, the particles were packed and firmly attached but still distinguishable from the surrounding bone. Of the 21 sites treated, 5 sites had an exposure of the implant cover screw during the healing period. An exposure of the granular material occurred in 4 sites, but loss of granules in only 3. Even in these sites no signs of infection or inflammation of the soft tissues were observed. At re-entry after 6 months, 10 sites were completely and 9 partially filled. For the partial fills, the mean remaining defect height was 1.6 mm (range: 0.6-3.0 mm). Two sites showed an increased defect of respectively 2.4 and 4.8 mm. No fixtures were lost. The present results indicate that deproteinized bovine bone is a safe filling material to fill remaining defects around implants installed in fresh extraction sockets.

Adolescent↗

PubMed2000

The accuracy of spiral tomography to assess bone quantity for the preoperative planning of implants in the posterior maxilla.

When planning to place implants in the posterior region of the maxilla, the location of the maxillary sinus floor is influencing the available bone height and the implant length chosen. The aim of the present study was to evaluate in vitro the spiral tomographic technique that could be used for pre-operative implant planning. Tomographs were taken of 6 dry human skulls using the Cranex Tome multifunctional unit (Orion Corporation Soredex, Helsinki, Finland). Three sites were selected in the left posterior maxilla and marked with gutta percha meaning a total of 18 sites (6 x 3 = 18) for interpretation. Bone height and width were measured on the tomographs and after sectioning also on the skulls. The values obtained from the measurements on tomographs were divided by an enlargement factor of 1.5 (as defined by the manufacturer) and then compared with those from the real measurements on the skulls. Real measurements were on average 0.24 mm (SD 0.19) lower than the tomographic measurements (P < 0.05). From the present results it could be concluded that spiral tomography using the recently developed Cranex Tome reveals sufficient information and detail for pre-operative planning of a limited edentulous region.

Adult↗

PubMed2000

The rôle of chlorhexidine in the one-stage full-mouth disinfection treatment of patients with advanced adult periodontitis. Long-term clinical and microbiological observations.

BACKGROUND/AIMS: Recent studies reported significant additional clinical and microbiological improvements when severe adult periodontitis was treated by means of a "one-stage full-mouth" disinfection instead of a standard treatment strategy with consecutive root planings quadrant per quadrant. The one stage full-mouth disinfection procedure involves scaling and root planing of all pockets within 24 h in combination with an extensive application of chlorhexidine to all intra-oral niches such as periodontal pockets, tongue dorsum, tonsils (chairside, and at home for 2 months). This study aims to examine the relative importance of the use of chlorhexidine in the one stage full-mouth disinfection protocol. METHODS: Therefore, 3 groups of 12 patients each with advanced periodontitis were followed, both from a clinical and microbiological point of view, over a period of 8 months. The patients from the control group were scaled and root planed, quadrant per quadrant. at two-week intervals. The 2 other groups underwent a one stage full-mouth scaling and root planing (all pockets within 24 h) with (Fdis) or without (FRp=full-mouth root planing) the adjunctive use of chlorhexidine. At baseline and after 1, 2, 4 and 8 months, the following clinical parameters were recorded: plaque and gingivitis indices, probing depth, bleeding on probing and clinical attachment level. Microbiological samples were taken from different intra-oral niches (tongue, mucosa, saliva and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media in order to evaluate the number of CFU/ml for the key-periodontopathogens. At baseline, an anonymous questionnaire was given to the patients to record the perception of each treatment (post operative pain, fever, swelling etc.). RESULTS: All 3 treatment strategies resulted in significant improvements for all clinical parameters, but the Fdis and FRp patients reacted always significantly more favourably than the control group, with an additional probing depth reduction of +/- 1.5 mm and an additional gain in attachment of +/- 2 mm (for pockets > or = 7 mm). Also from a microbiological point of view both the FRp and Fdis patients showed additional improvements when compared to the control group, as well in the reduction of spirochetes and motile organisms as in the number of CFU/ml of the key-pathogens, especially when the subgingival plaque samples were considered. The differences between FRp and Fdis patients were negligible. CONCLUSIONS: These findings suggest that the benefits of a "one-stage full-mouth disinfection" in the treatment of patients suffering from severe adult periodontitis probably results from the full-mouth scaling and root planing within 24 h rather than the beneficial effect of chlorhexidine. The raise in body temperature the second day after the full-mouth scaling and root planing seems to indicate a Shwartzman reaction.

Adult↗

PubMed2000

Biologic outcome of single-implant restorations as tooth replacements: a long-term follow-up study.

BACKGROUND: The replacement of a single tooth or several teeth by means of single-implant restorations is an increasingly used method that needs long-term validation. PURPOSE: The goal of this study was to evaluate the outcome of single-implant restorations by means of fixed restorations and to define the prognosis through marginal bone level estimations. MATERIALS AND METHODS: From November 1986 to June 1998, 270 Brånemark implants (215 in the upper jaw) were installed in 219 patients (106 males). Both anterior and posterior sites were involved. Of the 263 single restorations, 28 were placed in private dental offices. The patients were followed until June 1999. RESULTS: Twelve implants failed before or at abutment connection or within 6 months afterward. Only four implants failed later. The cumulative success rates were 93% for the implants and 96.5% for the restorations over a period of 11 years. The marginal bone loss during the first 6 months after abutment connection reached 0.71 mm and then dropped to 0.036 mm annually over a period of 10 years. CONCLUSIONS: Single-implant restorations (Brånemark System) are a reliable treatment with a good long-term prognosis. Failures were concentrated during the healing period and early loading phase.

Adolescent↗

PubMed2000

From osseointegration to osseoperception.

Periodontology has broadened its scope by the research and clinical use of osseointegrated implants. Since tactile and reflex functions have been associated with periodontal ligament neural receptors, osseoperception could be associated with endosseous and/or periosteal innervation.

Alveolar Process↗

PubMed2000

Periodontal health of orthodontically extruded impacted teeth. A split-mouth, long-term clinical evaluation.

BACKGROUND: Impaction of front teeth (often upper canines) can result in esthetic, functional, and phonetic problems, in addition to root resorption and chronic or acute infections. Most impacted front teeth can be extruded orthodontically after minor periodontal surgery. The purpose of this retrospective study was to examine the periodontal outcome of surgically exposed and orthodontically extruded impacted teeth compared with the spontaneously erupted contralateral teeth. METHODS: A total of 38 patients, who had been treated by a combined surgical and orthodontic approach (closed eruption technique by same periodontist and 2 associated orthodontists), underwent a periodontal re-examination after 4 to 10 years. Periodontal parameters (plaque and gingivitis indices, probing depth, bleeding on probing, gingival recession and width, bone level, and root resorption) of the orthodontically extruded teeth (test) were scored and compared with those of the contralateral naturally erupted teeth (control) in a masked set-up. RESULTS: No significant differences could be detected between test and control teeth, except for the gingival width, which was 1 mm larger for the spontaneously erupted teeth. CONCLUSIONS: The data indicate that orthodontic extrusion of impacted front teeth does not jeopardize their periodontal health. This procedure appears to be a satisfactory alternative to extraction and/or transplantation.

Adolescent↗

PubMed1999

Bone behavior around sleeping and non-sleeping implants retaining a mandibular hinging overdenture.

Since 1984 2 implants in the symphyseal area have been used in our center to retain a hinging overdenture. Because this technique was unknown at that time 1 extra implant was installed in between the 2 others and was left submerged (sleeping). The extra implant served as a rescue implant in case 1 of the 2 others would fail. It was the aim of the present report to compare the marginal bone behavior around those sleeping and non-sleeping implants. Between 1984 and 1987 20 completely edentulous patients were provided with 3 implants (Brånemark system), where from 2 were used to retain a hinging overdenture. Ten years later half of the patients could still be traced. Retroalveolar radiographs were made at the abutment installation and after 10 years. None of the non-sleeping or sleeping implants lost, at an individual basis, more than 1.6 and 0.7 mm of marginal bone respectively. On average, non-sleeping implants lost at the right- and left-hand side of the mandible 0.33 and 0.57 mm of bone respectively. However, sleeping implants lost on average 0.16 mm only. Thus non-sleeping implants lose on average more bone when compared to sleeping implants. Surgical trauma at the abutment connection is believed to be the most plausible cause of marginal bone loss around non-sleeping implants.

Aged↗

PubMed1999

Interdisciplinary treatment planning for orthodontic-prosthetic implant anchorage in a partially edentulous patient.

Successful orthodontic treatment is characterized by optimal anchorage control. Teeth or groups of teeth are united to counteract biomechanical reactive forces during orthodontic treatment. These classic anchorage control mechanisms are less efficient or even non-existent in partially edentulous patients who are missing multiple posterior teeth. However, osseointegrated oral implants ad modum Brånemark can provide optimal anchorage control for orthodontic tooth alignment and rehabilitation of occlusion through prosthetic implant restorations. Careful multidisciplinary planning based on complex diagnostic wax setup casts to determine exact implant location and orientation in line with future orthodontic tooth displacements and prosthetic implant crown restorations is the most important step in the overall treatment planning.

Adult↗

PubMed1999

Predictability of a three-dimensional planning system for oral implant surgery.

OBJECTIVES: To compare 2D CT alone with 2D + 3D reconstruction for pre-operative planning of implant placement. METHODS: Spiral CT scans of 33 consecutive patients were used for both reformatted 2D and 3D computer-assisted planning. The number, site and size of implants and the occurrence of anatomical complications during planning and implant placement were statistically compared using the percentage agreement and the Kendall's correlation coefficients (tau). Although planning was performed in 33 patients, implants were only placed in 21 patients. In 11 patients surgery was based on 2D + 3D imaging and in ten patients on 2D planning. RESULTS: Agreement between planning and placement of implants was highly significant for the implant sites selected. For 2D based planning and placement, agreement reached 68% (tau = 0.94). For 2D + 3D based planning and placement, agreement attained 73% (tau = 0.89). For planning and placement of implant size based on 2D images, agreement was 31% and not significant (tau = 0.23). When based on 2D + 3D images, agreement for implant size was 44% (tau = 0.5). Agreement was not significant for anatomical complications: 69% for 2D planning and 71% for 2D + 3D planning (tau = 0.24 for 2D and tau = 0.21 for 2D + 3D). CONCLUSIONS: The 3D planning system is a reliable tool for pre-operative assessment of implant placement. Both 2D and 2D + 3D planning have a good predictability for the number and site of the implants but less so for anatomical complications. However, the 2D + 3D planning provides a better pre-operative assessment of implant size.

Adult↗

PubMed1999

Five-year evaluation of implants placed at extraction and with dehiscences and fenestration defects augmented with ePTFE membranes: results from a prospective multicenter study.

BACKGROUND: Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations. Membranes also have been used to protect defects adjacent to implants placed at the time of extraction. The concept of guided bone regeneration relates to preferentially allowing cells from bone to migrate into various defects while excluding fibrous tissue and epithelium. The purpose of these procedures is to enhance bone-to-implant contact at the treated sites and to prevent mucosal complications. PURPOSE: The purpose of this article is to report clinical outcomes for implants placed at the time of extraction and augmented with expanded polytetrafluoroethylene (ePTFE) and followed for 5 years. The outcomes for implants with dehiscences and fenestrations augmented with ePTFE barriers and followed up to 5 years also are reported. METHODS AND MATERIALS: Four treatment centers participated in this study (Tucson, Gothenburg, Spokane, and Leuven). In the extraction group, teeth were removed for varying reasons, and Brånemark implants were placed and stabilized within the host bone. Defects present at the coronal implant aspect were covered with ePTFE barrier membranes. Flaps were rotated to cover the membrane-treated sites. If exposure of the material occurred prior to second-stage surgery, the membranes were removed. Barriers remaining unexposed were removed at second-stage surgery. The implants were followed up to 5 years. In the fenestration and dehiscence group, implants with exposed threads were augmented with ePTFE barrier membranes. The barriers were removed at appropriate intervals, and the patients were followed up to 5 years. Radiographic measurements were made from nonstandardized periapical radiographs at abutment connection and 1, 3, and 5-year follow-up visits. RESULTS: Forty patients participated in the extraction group. They received a total of 49 implants. Three implants failed prior to loading. The 5-year cumulative survival rates for implants placed at the time of extraction were 93.9% and 93.8%, respectively, for maxillary and mandibular implants. The average maxillary mesial and distal marginal bone loss (1-5 yr) was 0.3 mm (standard deviation [SD] = 1.5) and 0.3 mm (SD = 1.0). In mandibles, the average mesial and distal bone loss (1-5 yr) was -0.2 mm (SD = 0.5) and -0.05 mm (SD = 0.6), respectively. The dehiscence and fenestration group included 44 patients. Twenty-six were followed for up to 5 years. Eight patients experienced total implant failure. For dehiscences and fenestrations, the cumulative survival rates were 76.8% and 83.8% for maxillary and mandibular implants, respectively. The average maxillary mesial and distal bone loss (1-5 yr) was 0.4 mm (SD = 0.8) and 0.2 mm (SD = 0.9), respectively. In mandibles, the average mesial and distal marginal bone loss was 0.3 mm (SD = 0.9) and 0.3 mm (SD = 0.8), respectively. CONCLUSIONS: Implants placed at the time of extraction and augmented with ePTFE barrier membranes have favorable long-term predictability. On the other hand, long-term evaluation of implant dehiscences and fenestrations augmented with barrier membranes indicates that they have less favorable 5-year survival rates. Membrane augmentation of these may be questioned.

Adolescent↗

PubMed1999

Influence of inflammatory reactions vs. occlusal loading on peri-implant marginal bone level.

Plaque accumulation on abutments or implant surfaces induces an inflammatory reaction in the gingiva/alveolar mucosa just as around teeth. The longevity of oral implants can be jeopardized by either peri-implantitis and/or an occlusal overload. In the partially edentulous patient in whom pockets around teeth act as a reservoir for the colonization of the pockets around implants, the risk for inflammatory reactions of the peri-implant soft tissues seems especially more plausible than in the fully edentulous patient. This is especially true for implants with a very rough surface (e.g., plasma-sprayed), because of the positive relationship between surface roughness and supra- as well as subgingival plaque formation. Several medium-term (from 5 to 10 years) clinical studies support this hypothesis, through the observation of ongoing bone loss and subsequent decreasing success/survival percentages. Occlusal overload increases the risk for microfractures at the implant-bone interface in two-stage implants, which can result in significant marginal bone loss and even failure. There is ample evidence that occlusal factors are related to marginal angular defects around two-stage implants.

Alveolar Bone Loss↗

PubMed1999

A long-term evaluation of composite-bonded natural/resin teeth as replacement of lower incisors with terminal periodontitis.

BACKGROUND: In patients with severe peridontitis, lower incisors are prone to terminal breakdown. This study assessed the longevity of composite-bonded resin/natural teeth (reinforced only with a stainless steel mesh) as replacements for periodontally lost lower incisors. METHODS: Besides the longevity of the restoration, the periodontal condition of the abutment teeth, and the general satisfaction of the patient were evaluated retrospectively via a phone interview, in combination with an analysis of the patient's clinical dental file. RESULTS: The cumulative proportion of survival rate of these composite restorations was 80% after 5 years of function. No statistically significant difference was found between the survival distribution of one- and two-pontic bridges (P = 0.66). The abutment teeth demonstrated stable probing depths and a negligible loss in attachment (0.1 mm/year). The satisfaction ratings were also favorable. CONCLUSIONS: The data seem to suggest that composite bonding of 1 or 2 teeth can be considered a semi-permanent rehabilitation for the replacement of 1 or 2 periodontally lost lower incisors.

Adult↗

PubMed1999

Comparison of fluorescence microscopy and culture assays to quantitate adhesion of Porphyromonas gingivalis to mono- and multi-layered pocket epithelium cultures.

BACKGROUND: The present study compared 2 different methods (direct versus indirect evaluation) for the quantification of the adhesion of Porphyromonas gingivalis strains to in vitro cultured mono-layers of pocket epithelium. METHODS: The indirect culture viability assay (calculation of colony forming units) was compared to a direct microscopic evaluation using a novel fluorescent stain. The fluorescent kit was found to stain both bacteria and epithelial cells and enabled a differentiation between dead and living cells. RESULTS: Comparing the visual to the culture data, a high and significant correlation was found (Pearson's correlation = 0.75; P <0.001). The adhesion capacity was in general higher for dead epithelial cells than for living cells (P <0.01). Although comparable numbers of bacteria of 2 P. gingivalis strains (Pg 4 and Pg 5) were applied, Pg 4 showed a significantly lower adhesion capacity. This intra-strain variability was observed by the culture assay (2.3 x 10(6) versus 7.8 x 10(6)+/-2.7 x 10(6); P <0.01) and by the direct microscopy (P <0.01) for both live and dead epithelial cells. A second goal was to see whether there was a difference in the amount of bacterial adherence to mono- and multi-layers of in vitro cultured epithelium. No significant differences were found for the 5 examined P. gingivalis strains. However, interstrain differences in adhesion capacity were evident for both tissues. CONCLUSIONS: This study highlights the reproducibility of a direct microscopic evaluation of bacterial adhesion to in vitro cultured epithelial cells, and suggests both intrastrain (P. gingivalis) and inter-cell (live versus dead) variation in adhesion capacity. Studies are needed to determine the extent to which P. gingivalis strain variation is reflected in variation of other strains in humans.

Bacterial Adhesion↗

PubMed1999

One stage full- versus partial-mouth disinfection in the treatment of chronic adult or generalized early-onset periodontitis. I. Long-term clinical observations.

BACKGROUND: A standard treatment strategy for periodontal infections often consists of 4 consecutive sessions of scaling and root planing (per quadrant, at 1- to 2-week intervals), without proper disinfection of the remaining intra-oral niches for periodontopathogens. This could theoretically lead to a reinfection of previously disinfected pockets by bacteria from an untreated region/niche. This study aimed to investigate, over an 8-month period, the clinical benefits of a one stage full-mouth disinfection in the control of severe periodontitis. METHODS: Sixteen patients with early-onset periodontitis and 24 patients with severe adult periodontitis were randomly assigned to test and control groups. The control group was scaled and root planed, per quadrant, at 2-week intervals and given standard oral hygiene instructions. A one stage full-mouth disinfection (test group) was sought by scaling and root planing the 4 quadrants within 24 hours in combination with the application of chlorhexidine to all intra-oral niches for periodontopathogens. Besides oral hygiene, the test group also rinsed twice daily with a 0.2% chlorhexidine solution and sprayed the tonsils with a 0.2% chlorhexidine spray, for 2 months. The plaque index, gingival index, probing depth, bleeding on probing, gingival recession, and clinical attachment level were recorded at baseline and at 1, 2, 4, and 8 months afterwards. RESULTS: The one stage full-mouth disinfection resulted, in comparison to the standard therapy, in a significant (P <0.001) additional probing depth reduction and gain in attachment up to 8 months. For initial pockets > or =7 mm, the "additional" probing depth reduction at the 8 month follow-up was 1.2 mm for single-rooted and 0.9 mm for multi-rooted teeth, with corresponding additional gains in attachment of 1.0 mm and 0.8 mm, respectively. The additional improvements were observed for all subgroups (adult periodontitis, generalized early-onset cases, smokers), with the largest differences in the non-smoking adult periodontitis patients. CONCLUSIONS: These findings suggest that a one stage full-mouth disinfection results in an improved clinical outcome for the treatment of chronic adult or early-onset periodontitis as compared to scaling and root planing per quadrant at 2-week intervals.

Adult↗

PubMed1999

One stage full- versus partial-mouth disinfection in the treatment of chronic adult or generalized early-onset periodontitis. II. Long-term impact on microbial load.

BACKGROUND: Recent studies showed the clinical benefits of a one stage full-mouth disinfection, when compared to the worldwide standard treatment strategy of consecutive root planings per quadrant without proper disinfection of the remaining intraoral niches. The purpose of this study was to investigate the microbiological benefits of such a one stage full-mouth disinfection with special attention to all intraoral niches for periodontopathogens and to evaluate the perception by the patients of the new treatment strategy. METHODS: Sixteen patients with early-onset periodontitis and 24 patients with severe adult periodontitis were randomly assigned to test and control groups. The control group was scaled and root planed, per quadrant, at 2-week intervals and given oral hygiene instructions. The test group received the one stage full-mouth disinfection treatment. At baseline and after 1, 2, 4, and 8 months, microbiological samples were taken from all niches (tongue, mucosa, saliva, and pooled samples from single- and multi-rooted teeth). The samples were cultured on selective and non-selective media. Patient perception of the treatment was evaluated using a questionnaire. RESULTS: In comparison to the standard therapy, the one stage full-mouth disinfection resulted in significant additional microbial improvements. The test group showed larger reductions in the proportions of spirochetes and motile organisms in the subgingival flora, and more significant reductions in the density of key pathogens, with even the eradication of P. gingivalis. The beneficial effects in the other niches were primarily restricted to the number of colony-forming units/ml of black-pigmented bacteria, especially on the mucosa and in the saliva and to a lesser extent on the tongue. Both treatments were well tolerated by the patients and the overall severity rating for both therapies was comparable, although 4 quadrants were treated within 24 hours in the test group versus only 1 in the control group. The full-mouth disinfection approach resulted more frequently in a slight increase of body temperature, especially after the second day. CONCLUSIONS: These findings support the benefit of a one stage full-mouth disinfection in the treatment of patients with either chronic adult or early-onset periodontitis.

Adult↗

PubMed1999

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis.

BACKGROUND: A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control. METHODS: One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15. RESULTS: Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated. CONCLUSIONS: Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

Adult↗