Biomedical subjects

J Lindhe

Publications and source records attributed to J Lindhe.

At least 37 records · Page 2Linked to original sources

PubMed2001

Bone reactions adjacent to titanium implants subjected to static load of different duration. A study in the dog (III).

The aim of the present experiment was to study the effect of a long-standing lateral static load on the peri-implant bone. Three beagle dogs were used. The mandibular premolars were extracted and 12 weeks later 3 titanium implants (ITI(R) Dental Implant System) were installed in each quadrant. Crowns were fitted to all implants 12 weeks after the installation procedure. The anterior and central crowns were fused and connected to the posterior crown by an expansion screw. In the right side of the mandible, the expansion screws were activated every 2 weeks during a 46-week period. During the last 10 weeks of this period, an expansion force similar to that of the right side was applied in the left. The animals were sacrificed and block biopsies of each implant site harvested and prepared for histological analysis. Sites subjected to 10 weeks or 46 weeks of lateral load had a similar (i) distribution of bone markers (ii) proportion of bone density and (iii) degree of bone-to-implant contact. The proportion of fluorochromes was higher at sites subjected to 10 weeks of loading than at sites subjected to 46 weeks of loading.

Alveolar Process↗

PubMed2001

Re-osseointegration after treatment of peri-implantitis at different implant surfaces. An experimental study in the dog.

Peri-implantitis is a condition that includes soft tissue inflammation and rapid loss of bone. Treatment of peri-implantitis includes both antimicrobial and bone augmenting methods. The question of whether true re-osseointegration may occur following treatment of peri-implantitis is controversial. The aim of this study was to investigate whether the character of the implant surface was of importance for the occurrence of re-osseointegration following treatment of peri-implantitis. Four beagle dogs were used. The mandibular premolars were extracted. After 12 months, 3 ITI(R) solid screw dental implants were placed in each side of the mandible. In the left side, implants with a turned surface (Turned sites) were used, while in the right side implants with a SLA surface (SLA sites) were placed. After 3 months of healing, peri-implantitis was induced by ligature placement and plaque accumulation. When about 50% of the initial bone support was lost, the ligatures were removed. Five weeks later, treatment was initiated. Each animal received tablets of Amoxicillin and Metronidazole for a period of 17 days. Three days after the start of the antibiotic regimen, one implant site (experimental site) in each quadrant was exposed to local therapy. Following flap elevation, the exposed titanium surface was cleaned with the use of cotton pellets soaked in saline. The implants were submerged. Six months later, biopsies were obtained. Treatment resulted in a 72% bone fill of the bone defects at Turned sites and 76% at SLA sites. The amount of re-osseointegration was 22% at Turned sites and 84% at SLA sites. A treatment regimen that included (i) systemic administration of antibiotics combined with (ii) granulation tissue removal and implant surface cleaning resulted in resolution of peri-implantitis and bone fill in adjacent bone defects. Further, while substantial "re-osseointegration" occurred to an implant with a rough surface (SLA), bone growth on a previously exposed smooth surface (Turned) was minimal.

Alveolar Bone Loss↗

PubMed2001

Some local and systemic immunological features of prepubertal periodontitis.

OBJECTIVES: The aim of the present investigation was to study local (gingival) and systemic host defense characteristics in a sample of children exhibiting local prepubertal periodontitis (LPP). MATERIAL AND METHODS: 2 groups of subjects were included in the present study. One group consisted of 11 children (9.5+/-2.0 years) with signs of periodontal disease (LPP group). A 2nd group comprised 21 adults (48.1+/-5.8 years) with advanced periodontal disease: adult periodontitis (AP) group. Gingival biopsies and a sample of peripheral blood were obtained in each individual of the AP group and in 7 out of the 11 subjects in the LPP group. The biopsies were prepared for morphometrical and immunohistochemical analysis and the blood samples prepared for immunohistochemical analysis. RESULTS: The cellular infiltrates in the biopsies of the LPP group contained a larger proportion of lymphocytes and, in particular B cells, than was the case in the AP group. The TCR Valpha/Vbeta gene expression in the lesions in the AP group was dominated by Vbeta 17 and in the LPP group by Valpha2. The content in peripheral blood of various lymphocyte sub-populations and TCR Valpha/Vbeta gene expression in the 2 groups was almost similar. CONCLUSION: It is suggested that (i) the systemic host response in children with prepubertal periodontitis has many features in common with that seen in adult patients but that (II) local defense mechanisms in the periodontitis lesion of LPP differ from those in adult periodontitis.

Adolescent↗

PubMed2001

Longitudinal periodontal tissue alterations during supportive therapy. Findings from subjects with normal and high susceptibility to periodontal disease.

AIM: The aim of the study was to evaluate disease progression during supportive periodontal therapy in (i) a group of 225 subjects with "normal" (NG) and (ii) a group with high susceptibility (HSG; n= 109) to periodontal disease (based on their baseline disease status). MATERIAL AND METHODS: The following variables were recorded at the baseline examination (1 year after they received non-surgical periodontal therapy) and at the re-examination after 12 years of maintenance: number of teeth, plaque, probing pocket depth, probing attachment level, bone level in full mouth radiographs. All assessments were performed in a standardized manner and by well-trained and calibrated examiners. Supportive periodontal therapy was delivered 3-4 x per year and included repeated oral hygiene instruction and debridement. In addition, sites that bled on probing and had a PPD value of > or = 5 mm received subgingival instrumentation. RESULTS: A comparison between the findings at baseline and after 12 years revealed that in the NG, most subjects maintained their periodontal condition unchanged during the maintenance period; only a few subjects experienced tooth loss and the figures describing the mean amount of bone and attachment loss were small (0.5 mm and 0.3 mm respectively). The HSG patients experienced some tooth loss and also lost significant amounts of bone and attachment during the 12 years of SPT. Thus, in this group of subjects, the mean overall PAL loss amounted to 0.8 mm, i.e., 0.06 mm/tooth surface/year. In the NG, the overall attachment loss was significantly smaller: 0.5 mm, i.e. 0.04 mm/tooth surface/year. CONCLUSION: In subjects with a high susceptibility for periodontal disease who had been treated for this condition by non-surgical means, an SPT program including regularly repeated oral hygiene instruction and subgingival debridement, made it possible to maintain bone and attachment levels at a reasonably stable level over a 12-year period. A similar SPT provided to a group of subjects with normal susceptibility to periodontal disease, on the other hand, prevented almost entirely major tooth, bone and attachment loss.

Adult↗

PubMed2001

Osseintegration following treatment of peri-implantitis and replacement of implant components. An experimental study in the dog.

AIM: The aim of the present experiment was to study if the quality of the titanium surface is a decisive factor for osseointegration and re-osseointegration. MATERIAL AND METHODS: 2 Labrador dogs were used. The mandibular 1st molars and all premolars were removed bilaterally. 3 months later, 1 standard fixture and 3, 2-part "test fixtures" were installed in each side of the mandible. The text fixtures consisted of 1 6-mm long apical and 1 4-mm long coronal part connected with an internal screw. After 4 months, abutment connection was performed. 5 months later, a period of experimental peri-implantitis was initiated during which about 50% of the supporting bone tissue was lost. The dogs were later subjected to a treatment that included (i) systemic administration of antibiotics and (ii) surgical debridement of all implant sites. The abutments and the coronal parts of the text fixtures were removed. All parts of the exposed portion of the standard fixtures, the connecting screw and the apical part of the test fixtures were meticulously cleaned by mechanical means. A pristine, coronal fixture part was via the connecting screw attached to the apical fixture part of each text fixture. All fixtures were submerged. 2 weeks later, a fluorochrome was injected intravenously. After 4 months, biopsies of the implant sites were dissected and prepared for ground sectioning and analysis. RESULTS: It was demonstrated that re-osseointegration failed to occur to implant surfaces (standard) exposed to bacterial contamination, but did consistently occur at sites where a pristine implant component was placed in the bone defect following surgical debridement. CONCLUSION: The above findings seem to imply that the quality of the titanium surface is of decisive importance for both osseointegration and re-osseointegration.

Alveolar Bone Loss↗

PubMed2001

The effect of systemic antibiotics in the treatment of patients with recurrent periodontitis.

BACKGROUND: Subjects with periodontal disease exist who either (i) respond poorly to initial mechanical therapy ("refractory" periodontitis) or (ii) fail to adopt adequate self-performed plaque control techniques and hence develop recurrent disease ("recurrent" periodontitis) at multiple sites during the supportive treatment phase (SPT). Various systemic antibiotic regimens have been tried as adjuncts to the mechanical (re-) treatment of such "difficult to treat"-patients. While most studies indicated a positive outcome of the adjunctive therapy, some clinical investigators reported that this additional measure provided little or no benefit. AIM: The aim of the present investigation was to study the more long term effect of adjunctive antibiotic therapy in the re-treatment of patients with a well defined history of recurrent periodontitis. MATERIAL AND METHODS: 17 subjects with recurrent advanced periodontal disease were, following a baseline examination, subjected to non-surgical therapy including the use of systemic antibiotics (amoxicillin and metronidazole). They were placed in a careful SPT program and re-examined after 1, 3 and 5 years. The examinations included both clinical and microbiological assessments. RESULTS: It was demonstrated that in subjects with advanced and recurrent periodontitis, re-treatment including (i) comprehensive scaling and root planing (SRP), (ii) systemic administration of antibiotics and (iii) meticulous supragingival plaque control by both mechanical and chemical means established periodontal conditions that in the short term (3 years) and in the majority of subjects could be properly maintained by traditional SPT measures. Between 3 and 5 years, however, only 5 of the 17 subjects exhibited stable periodontal attachment levels. CONCLUSIONS: Some deep pockets and furcations were most likely inadequately instrumented during the active treatment phase. Microorganisms residing in biofilms left in such locations were probably not sufficiently affected by the 2 weeks of adjunctive antibiotic therapy. It is suggested that removal of certain subgingival deposits, therefore, may require surgical intervention.

Adult↗

PubMed2001

The long-term effect of systemic tetracycline used as an adjunct to non-surgical treatment of advanced periodontitis.

AIM: In the present study both the short- and the long-term effects were evaluated of a treatment that, during the phase of basic therapy, included administration of systemic tetracycline and non-surgical intervention. MATERIAL AND METHODS: 35 adult human subjects with advanced periodontitis, 19 females and 16 males, aged between 24 and 60 years, were included in a test group. 80 age- and sex-matched adult periodontitis subjects were recruited for a control group (42 females and 38 males). A baseline examination included assessment of the following parameters: number of teeth, plaque, bleeding on probing, probing attachment level, probing pocket depth. In radiographs, the distance between the cemento-enamel junction and the alveolar bone crest was determined at all interproximal sites. The subjects were given oral hygiene instruction. The members of the test group were provided with tablets with 250 mg of tetracycline hydrochloride and were instructed to take 1 tablet 4x per day for a period of 3 weeks. No antibiotic was given to the subjects in the control group. During the 3-week interval, all participants received 4-6 sessions of non-surgical periodontal therapy. All subjects were subsequently enrolled in a maintenance care program and were provided with supportive periodontal therapy (SPT) 3-4x per year. Clinical re-examinations were performed after 1, 3, 5 and 13 years. RESULTS: The present investigation demonstrated that tetracycline administered during a 3-week period concomitant with non-surgical treatment enhanced the outcome of mechanical therapy. At the re-examination 1 year after active therapy, there was in the test group an average gain in probing attachment that was almost 3x higher than the gain that occurred in an age and sex matched Control group. Re-examinations after 3, 5, and 13 years of SPT disclosed that this short-term benefit was not maintained in the longer perspective. CONCLUSION: The beneficial effect of systemically administered tetracycline on probing attachment level occurred in the first year post-therapy. Annual rates of probing attachment level change from 1 to 13 years did not differ between groups.

Adult↗

PubMed2001

Experimental peri-implant mucositis in man.

OBJECTIVES: The purpose of this study was to examine reactions of gingiva and peri-implant mucosa (PiM) to de novo plaque accumulation in humans. MATERIAL AND METHODS: Prior to the start of the study, which included 12 partially edentulous subjects, a 3-week plaque control program was performed. Ethical approval was granted by the local ethics committee. On day 0, 2 soft tissue biopsies were harvested, 1 from a tooth and 1 from an implant site in every subject. After 3 weeks of undisturbed plaque accumulation (day 21), 2 additional biopsies were obtained from the gingiva and PiM in each subject. The tissue samples, each 4x4 mm in size, were snap frozen and prepared for immunohistochemical analysis. RESULTS: The size of the infiltrate (ICT) in the day 0 biopsies, was about 0.03 mm2 in both the gingiva and PiM. At the end of the plaque accumulation period, the size of the lesion had significantly increased in both groups and occupied an area of 0.26 mm2 in the gingiva and 0.14 mm2 in PiM. In the biopsies presenting day 0, the proportions of the various cell populations examined were similar in the gingiva and in PiM. The tissue fractions of almost all types of cells increased during the 3 weeks, but the mean change for each cell type was greater in the gingiva than in PiM. The CD3/CD19 ratio decreased in the gingiva between day 0 and 21, but increased in PiM. CONCLUSION: The results of the present study indicated that plaque accumulation induced an inflammatory response characterized by increased proportions of T- and B-cells in the ICT of both the gingiva and the PiM. Although not statistically significant, the host response in the gingiva tended to be more pronounced than in the peri-implant mucosa.

Aged↗

PubMed2001

Initial outcome and long-term effect of surgical and non-surgical treatment of advanced periodontal disease.

AIM: A clinical trial was performed to determine (i) the initial outcome of non-surgical and surgical access treatment in subjects with advanced periodontal disease and (ii) the incidence of recurrent disease during 12 years of maintenance following active therapy. MATERIAL AND METHODS: Each of the 64 subjects included in the trial showed signs of (i) generalized gingival inflammation, (ii) had a minimum of 12 non-molar teeth with deep pockets (> or =6 mm) and with > or =6 mm alveolar bone loss. They were randomly assigned to 2 treatment groups; one surgical (SU) and one non-surgical (SRP). Following a baseline examination, all patients were given a detailed case presentation which included oral hygiene instruction. The subjects in SU received surgical access therapy, while in SRP non-surgical treatment was provided. After this basic therapy, all subjects were enrolled in a maintenance care program and were provided with meticulous supportive periodontal therapy (SPT) 3-4 times per year. Sites that at a recall appointment bled on gentle probing and had a PPD value of > or =5 mm were exposed to renewed subgingival instrumentation. Comprehensive re-examinations were performed after 1, 3, 5 and 13 years of SPT. If a subject between annual examinations exhibited marked disease progression (i.e., additional PAL loss of > or =2 mm at > or =4 teeth), he/she was exited from the study and given additional treatment. RESULTS: It was observed that (i) surgical therapy (SU) was more effective than non-surgical scaling and root planing (SRP) in reducing the overall mean probing pocket depth and in eliminating deep pockets, (ii) more SRP-treated subjects exhibited signs of advanced disease progression in the 1-3 year period following active therapy than SU-treated subjects. CONCLUSION: In subjects with advanced periodontal disease, surgical therapy provides better short and long-term periodontal pocket reduction and may lead to fewer subjects requiring additional adjunctive therapy.

Adult↗

PubMed2001

Orthodontic movement in bone defects augmented with Bio-Oss. An experimental study in dogs.

OBJECTIVE: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss. MATERIAL AND METHODS: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. RESULTS: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. CONCLUSION: During the orthodontic tooth movement the graft material (Bio-Oss) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

Alveolar Process↗

PubMed2001

The use of PVP-iodine as an adjunct to non-surgical treatment of chronic periodontitis.

OBJECTIVE: The present study was performed to assess the effect of topically-applied PVP-iodine, used as an adjunct both during basic non-surgical therapy and at re-treatment during the long-term maintenance of patients with advanced periodontal disease. MATERIAL AND METHODS: 223 patients with advanced destructive periodontitis were recruited. The participants met the following inclusion criteria: (i) a minimum of 8 non-molar teeth, (ii) probing pocket depth of > or = 6 mm at > or = 2 teeth in each dentate quadrant, and radiographic bone loss exceeding 40% at the same teeth. A baseline I examination included assessment of plaque, gingivitis, probing pocket depth (PPD), probing attachment level (PAL) and radiographic bone height (RxBL). Following baseline I, the patients were stratified into 2 treatment groups; 2 subjects out of 3 were included in a control group and 1 in a test group. All participants, on an individual basis, received a case presentation and were instructed in proper self-performed plaque control measures. Non-surgical therapy was performed by the use of an ultrasonic device. The instrumentation in the test group was combined with the administration of 0.1% PVP-iodine. All subjects were recalled for comprehensive examinations 3, 6 and 12 months (baseline II) after baseline I and then after 3, 5 and 13 years of maintenance therapy. PAL determinations were performed annually. Subjects (losers) who at the re-examinations after 1, 2 and 3 years of maintenance demonstrated an annual further loss of PAL > or = 2 mm at > or = 4 teeth were exited from the study and referred for re-treatment. There were 9 losers in the test and 31 in the control group. In addition, 8 subjects in the test and 25 subjects in the control group withdrew from the trial for reasons unrelated to the study. These 73 subjects were not included in the data presentation from the various examinations. RESULTS: It was demonstrated that non-surgical periodontal therapy resulted in (i) improved gingival conditions, (ii) reduced PPD, (iii) gain in PAL. It was also documented that the topical application of 0.1% PVP-iodine in conjunction with the mechanical root debridement established conditions which further improved the outcome of therapy. This was evidenced by the fact that at the 3, 6, and 12 months re-examinations after baseline I, the test group had significantly lower mean PPD values and significantly more gain of PAL than the control group. During the 12 years of SPT, it was possible for most subjects in both groups to maintain shallow pockets and to avoid marked further loss of PAL. There were, however, a larger number of losers in the control than in the test group. CONCLUSION: PVP-iodine, topically applied during subgingival instrumentation, may improve the outcome of non-surgical periodontal therapy.

Administration, Topical↗

PubMed2000

Bone healing around implants placed in a jaw defect augmented with Bio-Oss. An experimental study in dogs.

The present experiment was carried out to study some tissue reactions around implants that were placed in an edentulous ridge which had been augmented with deproteinized natural bovine cancellous bone mineral. In 4 male beagle dogs, the premolars in the right side of the mandible were extracted and a large buccal ridge defect was created by mechanical means. The bone plate at the lingual aspect of the defect was left intact. 5 months later, the distal 2/3 of the defect area was augmented with Bio-Oss (Geistlich Sons Ltd, Wolhusen, Switzerland) mixed with a fibrin sealer (Tisseel, Immuno AG, Vienna, Austria). After 3 months of healing, 3 fixtures (Astra Tech AB, Mölndal, Sweden; TiO-blast; 8x3.5 mm) were installed in the mandible; 2 were placed in the augmented portion and I was placed in the non-augmented portion of the defect. After a healing period of 3 months, abutment connection was performed and a plaque control period initiated. 4 months later, the dogs were sacrificed and each implant region was dissected. The tissue samples were dehydrated, embedded in plastic, sectioned in the bucco-lingual plane and examined in the light microscope. It was observed that osseointegration failed to occur to implant surfaces within an alveolar ridge portion previously augmented with Bio-Oss. In the augmented portion of the crest, the graft particles were separated from the host tissue as well as from the implant by a well-defined connective tissue capsule. Although the lingual aspect of all fixtures (test and control) was in contact with hard tissue at the time of installation, after 4 months of function, a deep vertical bone defect frequently had formed at the lingual surface of the implants. It was concluded that in this model (i) Bio-Oss failed to integrate with the host bone tissue and (ii) no osseo-integration occurred to the implants within the augmented portion of the crest.

Alveolar Ridge Augmentation↗

PubMed2000

Anchorage of titanium implants with different surface characteristics: an experimental study in rabbits.

PURPOSE: To compare the anchorage of titanium implants with different surface roughness and topography and to examine histologically the peri-implant bone after implant removal. MATERIALS AND METHODS: Screw implants with five different surface topographies were examined: (1) turned ("machined"), (2) TiO2-blasted with particles of grain size 10 to 53 microns; (3) TiO2-blasted, grain size 63 to 90 microns; (4) TiO2-blasted, grain size 90 to 125 microns; (5) titanium plasma-sprayed (TPS). The surface topography was determined by the use of an optical instrument. Twelve rabbits, divided into two groups, had a total of 120 implants inserted in the tibiae. One implant from each of the five surface categories was placed within the left tibia of each rabbit. By a second operation, implants were installed in the right tibia, after 2 weeks in group A and after 3 weeks in group B. Fluorochrome labeling was performed after 1 and 3 weeks. Removal torque (RMT) tests of the implants were performed 4 weeks after the second surgery in group A and 9 weeks after the second surgery in group B. Thus, in group A, two healing groups were created, representing 4 and 6 weeks, respectively. The corresponding healing groups in group B were 9 and 12 weeks. The tibiae were removed, and each implant site was dissected, fixed, and embedded in light-curing resin. Ground sections were made, and the peri-implant bone was analyzed using fluorescence and light microscopy. RESULTS: The turned implants had the lowest Sa and Sy values, whereas the highest scores were recorded for the TPS implants. The corresponding Sa and Sy values for the TiO2-blasted implants were higher when a larger size of grain particles had been used for blasting. At all four observation intervals, the TPS implants had the highest and the turned implants the lowest RMT scores. The differences between the various TiO2-blasted implants were, in general, small, but the screws with the largest Sa value had higher RMT scores at 6, 9, and 12 weeks than implants with lower Sa values. The histologic analysis of the sections representing 6, 9, and 12 weeks revealed that fractures or ruptures were present in the marginal, cortical peri-implant bone. In such sections representing the TPS and TiO2-blasted implant categories, ruptures were frequently found in the zone between the old bone and the newly formed bone, as well as within the newly formed bone. CONCLUSIONS: The present study demonstrated that a clear relation exists between surface roughness, described in Sa values, and implant anchorage assessed by RMT measurements. The anchorage appeared to increase with the maturation of bone tissue during healing.

Animals↗

PubMed1999

Resolution of peri-implantitis following treatment. An experimental study in the dog.

The aim of the present experiment was i) to study the effect of anti-microbial therapy of experimentally induced peri-implantitis lesions and ii) to assess features of bone regrowth following treatment. Four beagle dogs were used. Three titanium fixtures (Brånemark System) were installed in each quadrant of the mandible (premolars previously extracted). Abutment connection was performed 5 months later and ligature induced breakdown was initiated. The ligatures were removed when approximately 50% of the initial bone support was lost. A 3-week antibiotic regimen (amoxicillin and metronidazole) was initiated 1 month later. Two days after the start of the antibiotic administration, the experimental implant sites were exposed to local therapy. The abutments were removed and the exposed fixture surfaces were treated with an abrasive (pumice) administered via a rotating brush (left side) or cleaned with cotton pellets soaked in saline (right side). Cover screws were attached to the fixtures and the implants were submerged. Fluorochromes were injected intravenously 2 weeks, 4 weeks and 12 weeks after surgery. The animals were killed 7 months after surgery and block biopsies of each implant site were dissected and prepared for histological analysis. The findings of the examinations disclosed that the inflammatory lesion was resolved and new bone formation had occurred in the previous defect following antimicrobial and local therapy. The amount of "re-osseointegration" that had taken place, however, was small. Indeed, at all experimental implant sites, a thin connective tissue capsule was found to separate the implant surface from the newly formed bone.

Administration, Oral↗

PubMed1999

The use of barrier membranes and enamel matrix proteins in the treatment of angular bone defects. A prospective controlled clinical study.

UNLABELLED: In the present prospective clinical trial, the effect of various regenerative procedures performed at sites with angular bone defects were evaluated. The main outcome variable was probing attachment alteration. MATERIAL AND METHODS: 40 subjects, aged 32-61 years participated. They met the following inclusion criteria: (i) presence of generalized, advanced periodontal tissue destruction; (ii) presence of 2 similar, contralateral, angular bone defects (experimental sites) located in either the maxilla or the mandible; (iii) the defect site must exhibit a probing pocket depth (PPD) of > or = 6 mm, a probing attachment level (PAL) of > or = 7 mm, and a depth of the intrabony component of > or = 3 mm. All subjects had a good oral hygiene standard, were in good general health and did not use any medication. Prior to the start of the study, all subjects received non-surgical treatment for periodontal disease. Baseline clinical measurements (plaque, gingivitis, PPD, PAL and soft tissue recession) of the selected experimental sites were obtained 6 months after the completion of basic therapy. The 40 subjects were randomly divided into 4 treatment groups including 10 subjects each: 3 membrane groups and one Emdogain group. 1 h before surgery, the patients were given 3 g of Amoxicillin. No other antibiotics were prescribed. The test and control sites were treated during the same surgical session. Full thickness flaps were elevated and the exposed root surfaces were planed. Membrane placement: The root surface was rinsed with saline. A barrier membrane (Guidor or Resolut or Periodontal (e-PTFE) material) was positioned to cover the defect and the adjacent 2-3 mm of bone tissue. The control treatment was identical to the test treatment with the exception of barrier placement. Emdogain placement: The exposed root surfaces at both the test and control sites were, during a 2-min period, conditioned with a 24% EDTA gel. Emdogain was applied to the exposed root surface of the test site. In the control site, the vehicle, the PGA gel, was used as placebo control. The flaps were closed and sutured to obtain a complete coverage of the intrabony defect. RESULTS: Re-examinations, which were performed 12 months after surgery, disclosed that regenerative therapy, including either the use of barrier membranes or application of enamel matrix proteins to an instrumented root surface in an angular, intrabony defect, enhanced outcome variables such as probing pocket depth and probing attachment gain. It was furthermore demonstrated that clinical improvements were better at sites with deep, than at sites with shallow, intrabony defects. CONCLUSION: The 4 regenerative modalities tested appeared to be equally effective in terms of PPD reduction and PAL gain, and superior to open flap curettage alone.

Adult↗

PubMed1999

Periodontal tissue alterations following Emdogain treatment of periodontal sites with angular bone defects. A series of case reports.

UNLABELLED: The aim of the present study was to assess the predictability of probing attachment gain and probing pocket depth reduction following Emdogain treatment at sites with deep angular bone defects. MATERIAL AND METHODS: 108 consecutively-treated periodontal patients (mean age 55.8 years) were included. Each subject exhibited at least 1 deep interproximal intrabony defect that could be identified as an experimental site based on the inclusion criteria: (i) probing pocket depth > or = 5 mm, (ii) probing attachment loss > or = 6 mm, (iii) radiographic evidence of an interproximal bone defect with a > or = 3 mm intrabony component. A total of 145 defects met the criteria for inclusion. All subjects received non-surgical periodontal therapy. This included subgingival instrumentation in all parts of the dentition. At least 6 months after the completion of this treatment, a baseline examination was performed to characterise the experimental site. Reconstructive therapy was subsequently performed. Full-thickness periodontal flaps were elevated, and the root surface scaled and planed. No bone recontouring was performed. A gel containing 24% EDTA was applied on the exposed root and was kept in place for 2 min. A preparation of enamel matrix proteins was applied to the root surface and adjacent defect space. The flaps were replaced and closed with sutures. The experimental sites were re-examined 12 months after reconstructive surgery. RESULTS: The re-examination demonstrated that a treatment including the application of enamel matrix proteins at periodontal sites with angular defects resulted in a mean probing attachment level gain of 4.6 mm and a probing pocket depth reduction of 5.2 mm. 87% of all sites treated exhibited a probing attachment gain of > 2 mm. One site suffered probing attachment loss. The radiographic assessments revealed that the bone defect had been reduced in depth by 2.9 mm on average. The reduction in defect size corresponded to an average bone fill of 69% of the original defect. In 43% of the defects, the bone fill amounted to > or = 80%. CONCLUSION: The overall probing pocket depth reduction, probing attachment level gain, and soft tissue recession, that results following Emdogain therapy, is similar to the corresponding outcome variables following GTR.

Combined Modality Therapy↗

PubMed1999

The effect of a triclosan/copolymer dentifrice on healing after non-surgical treatment of recurrent periodontitis.

The present study examined whether the daily use of a triclosan/copolymer dentifrice enhanced healing following non-surgical periodontal therapy at sites with progressive attachment loss in periodontitis-susceptible subjects: 60 subjects who had been (i) treated for advanced periodontal disease using nonsurgical means and (ii) had been enrolled, for at least 3-5 years, in a maintenance care program that called for prophylaxis once every 3 months. During the course of this maintenance period, all 60 subjects had suffered recurrent periodontitis at > or = 2 sites at several intervals. Following a baseline examination, all 60 subjects received, on an individual basis, detailed instruction in proper self-performed plaque control methods. They were stratified in 2 balanced groups (test and control groups). The members of the test group were assigned to use a triclosan/copolymer/fluoride-containing dentifrice, while the control group used a placebo dentifrice. During the following 3 years, all participants were recalled every 3 months for an evaluation of their oral hygiene standard. Re-examinations were performed after 6, 12, 24 and 36 months. In conjunction with the re-examinations, sites (loser sites) which exhibited additional probing attachment loss (> or = 2 mm) were identified. The loser sites were exposed to professional therapy. Thus, the site was anaesthetized and the surface carefully scaled and root planed (S/RP). Alterations regarding probing pocket depth (PPD), probing attachment level (PAL), and bleeding on probing (BoP) that occurred in the interval between S/RP and 36 months were analyzed. In the control group, 126 loser sites, 67 identified at the 12-month and 59 at the 24-month examinations, were subjected to S/RP. The corresponding number of loser sites in the test group was 85 (48 at 12 months and 37 at 24 months). At the time of S/RP, about 60% of the sites were BoP (+) in both groups. Following treatment, there was a reduction in the number of sites with gingivitis. While the reduction in the control group was modest (6.8%), in the test group, the improvement was more marked (27.5%). Following S/RP, there was also a reduction of the mean PPD in both groups. This decrease amounted to 1.7 mm in the test group and was significantly (p<0.05) smaller (0.6 mm) in the control. Finally in the interval between S/RP and 36 months, there was an improvement of the probing attachment level in both groups. The mean PAL gain was, however, significantly higher in the test than in the control group (1.8 mm versus 0.7 mm; p<0.01).

Anti-Infective Agents, Local↗

PubMed1999

Some effects of periodontal therapy on local and systemic immunological parameters.

The aim of the present investigation was to study the effect of nonsurgical periodontal therapy on some local (gingival) and systemic host defense characteristics in subjects with advanced periodontal disease. 16 individuals with advanced periodontal disease were recruited. Following a clinical examination, the 3 deepest interproximal sites in the upper and lower premolar- or molar segments were selected for further analysis. Samples from the subgingival microbiota were obtained from the pocket of the selected sites and were prepared for a microbiological examination. The gingival tissue at one of the selected sites was also biopsied. Each excised soft tissue specimen was snap frozen and prepared for immunohistochemical analysis. A sample of peripheral blood was obtained from each individual and prepared for immunohistochemical analysis. Following the baseline examination, all 16 patients received periodontal therapy including oral hygiene instruction and scaling and root planing. Re-examinations regarding the clinical parameters were performed, the subgingival microbiota harvested from the sampling sites and one gingival biopsy was collected at 12 months and 24 months, respectively, among the selected sites. Samples of peripheral blood were obtained from the subjects at the 24-month re-examination. It was demonstrated that non-surgical periodontal therapy effectively reduced symptoms such as gingivitis and probing pocket depth in the subject sample and improved the overall probing attachment level. The treatment applied also markedly reduced (i) the total number of micro-organisms present in selected gingival pockets as well as (ii) the relative proportions of A. actinomycetemcomitans, P. gingivalis and P. intermedia of the subgingival microbiota. The improved clinical condition was, in addition, accompanied by a substantial reduction in the size of the inflammatory lesion (P-ICT) which in the soft tissue samples harvested at baseline was found to reside lateral to the pocket epithelium. Also qualitative alterations occurred in the lesions. Hence, following therapy (i) both the density of CD19 positive cells and the proportion of CD3 positive cells expressing TCR Vbeta genes were reduced in the P-ICT. while (ii) the overall relative number of CD3 positive cells remained unchanged. In conclusion, non-surgical periodontal therapy markedly changed the size and composition of the plaque associated lesion in the gingival tissue but apparently failed to affect the relative distribution of lymphocyte subsets in peripheral blood.

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