Biphasic alloplastic graft used to preserve the dimension of the edentulous ridge: an experimental study in the dog.

BACKGROUND: Loss of teeth results in marked qualitative and quantitative alterations of the alveolar process at the edentulous site. It was observed that a graft comprised of bovine bone mineral placed in the fresh extraction socket delayed tissue modeling, but preserved the dimension of the ridge at edentulous sites. OBJECTIVE: To analyze the influence of a biphasic synthetic graft on tissue modeling and remodeling during healing of extraction wounds. MATERIAL AND METHODS: Five beagle dogs were used. Two premolars in the maxilla and two in the mandible were included. Full thickness flaps were elevated and the distal roots were removed. An alloplastic graft (BPCAP; α-TCP core coated with nanocrystalline biomimetic hydroxyapatite) embedded in porcine collagen was placed to fill the fresh extraction socket of the premolar sites. Flaps were replaced to cover the entrance of the extraction sockets during early healing. The extraction and grafting procedures were scheduled to allow for the study of 1, 2, and 3 months socket healing. The biopsies from the maxillary sites were decalcified, embedded in paraffin, and stained to allow the study of various aspects of hard tissue formation. The biopsies from the mandibular sites were processed for ground sectioning and used to evaluate alterations of ridge dimensions after 3 months of socket healing. RESULTS AND CONCLUSION: It was documented that the biphasic alloplastic graft did not undergo marked resorption during tissue modeling and remodeling, but allowed large amounts of bone to form within the post-extraction site. Grafting the experimental sites with this biomaterial furthermore counteracted ridge resorption that otherwise occurs following tooth extraction.

Effect of a xenograft on early bone formation in extraction sockets: an experimental study in dog.

AIM: The aim of this study was to study the effect on early bone formation resulting from the placement of a xenograft in the fresh extraction socket in dogs. MATERIAL AND METHODS: Five beagle dogs were used. The distal roots of the third and fourth mandibular premolars were removed. In one quadrant, a graft consisting of Bio-Oss Collagen was placed in the fresh extraction wound, while the corresponding premolar sites in the contra-lateral jaw quadrant were left non-grafted. After 2 weeks of healing, the dogs were perfused with a fixative, the mandibles removed, the experimental sites dissected, demineralized, sectioned in the mesio-distal plane and stained in hematoxyline-eosine. RESULTS: The central portion of the non-grafted sockets was occupied by a provisional matrix comprised of densely packed connective tissue fibers and mesenchymal cells. Apical and lateral to the provisional matrix, newly formed woven bone was found to occupy most of the sockets. In the apical part of the grafted sockets, no particles of the xenograft could be observed but newly formed bone was present in this portion of the experimental site. In addition, limited numbers of woven bone trabeculae occurred along the lateral socket walls. The central and marginal segments of the grafted sockets, however, were occupied by a non-mineralized connective tissue that enclosed Bio-Oss particles that frequently were coated by multinucleated cells. CONCLUSIONS: The placement of Bio-Oss Collagen in the fresh extraction wound obviously delayed socket healing. Thus, after 2 weeks of tissue repair, only minute amounts of newly formed bone occurred in the apical and lateral borders of the grafted sockets, while large amounts of woven bone had formed in most parts of the non-grafted sites.

The effect of a triclosan dentifrice on mucositis in subjects with dental implants: a six-month clinical study.

OBJECTIVE: The objective of the present clinical study was to assess the effect of the use of a dentifrice containing triclosan on peri-implant mucositis in subjects that had been restored with dental implants. METHODS: The trial was designed as a double-blind, randomized, two-treatment, parallel-group clinical study. Sixty male and female subjects, aged 30-70 years, were recruited. All subjects had lost teeth due to periodontal disease, and had been restored with a minimum of two implants at least one year prior to the start of the trial. Subjects were randomly assigned to two treatment groups. The subjects in the test group (Test) brushed their teeth and implant-supported restorations with a dentifrice containing triclosan, while the control subjects brushed with a sodium fluoride dentifrice. Only subjects with a minimum of one implant site showing clinical signs of peri-implant mucositis, i.e., bleeding after probing, were enrolled in the study. Clinical examinations were performed at baseline, and after three and six months. The following parameters were scored: Probing pocket depth (PPD), bleeding on probing (BoP), and plaque. The change from baseline within each treatment group at three months and six months was evaluated for all parameters using ANOVA and ANCOVA. RESULTS: Subjects with peri-implant mucositis who used a dentifrice containing 0.3% triclosan, as an adjunct to mechanical tooth brushing, exhibited significantly fewer clinical signs of inflammation than subjects who used a regular fluoride dentifrice at six months. The BoP scores were reduced from 53.8% to 29.1% in the Test group, whereas in the same interval there was an increase from 52.3% to 58.8% in the Control group. Furthermore, the individual mean PPD, as well as the frequency of sites with 5 mm and > or = 6 mm deep pockets, were reduced significantly more in the Test than in the Control group. CONCLUSION: The regular use of a dentifrice containing triclosan may reduce the clinical signs of inflammation in the mucosa adjacent to dental implants.

The effect of elimination of jiggling forces on periodontally exposed teeth in the dog.

The aim of the present investigation in dogs was to analyze the effect on periodontal disease induced by a combination of ligatures and jiggling trauma, when the jiggling forces are eliminated. The experiment was performed in six dogs. On Day 0 a phase of periodontal tissue breakdown was initiated around the mandibular fourth premolars (4P; P4) by placing plaque retention ligatures around the necks of the teeth. The ligatures were changed once a month during a 90-day period. On Day 90 the ligatures were removed. On Day 0 trauma from occlusion (jiggling) was also produced in the 4P and P4 region. On Day 90 the jiggling trauma was removed from the 4P-region (test) while it was maintained in the P4-region (control). Tooth mobility measurements and radiographic examinations were carried out on experimental Days 0, 30, 60, 90, 180, and 360. One dog was sacrificed on Day 90 and the remaining five on day 360. Following sacrifice, tissue sections comprising 1M, 4P, 3P, P3, P4, M1 were obtained and subjected to microscopic analysis. Removal of the jiggling trauma from the test teeth resulted in a markedly decreased tooth mobility, but the loss of connective tissue attachment on Day 360 was similar in the test and control sites. This means that although the control teeth had an increased mobility and a widened periodontal ligament space, the height of the remaining periodontal tissue support was similar in the test and control tooth regions.

Lack of significance of increased tooth mobility in experimental periodontitis.

This experiment was carried out in order to study the rate of progression of experimentally produced periodontal tissue breakdown in teeth which prior to the placement of cotton floss ligatures either had a normal or a permanently increased tooth mobility. Six beagle dogs were used. Trauma from occlusion of the jiggling type was produced on test teeth using a model previously described. Four months later experimental periodontal tissue breakdown was induced around both control and test teeth by placing cotton floss ligatures around the necks of the teeth. The ligatures which were exchanged once every 4 weeks during a 4-month period were replaced at the level of the gingival margin. Tooth mobility measurements and radiographic examinations were performed on Days 0, 30, 60, 90, 120, 160, 240 and 300. One dog was killed on Day 120 and the remaining 5 dogs on Day 300. Biopsies of the test and control teeth were fixed in formalin, decalcified, embedded in paraffin and mesiodistal sections cut with the microtome set at 4 micron. The results demonstrated that the degree of periodontal breakdown, initiated and maintained by ligature placement and plaque accumulation, was similar around teeth with a wide periodontal ligament space and in teeth with a normal width of the periodontium. In other words, progression of the plaque-associated lesions appeared to be unrelated to the width of the periodontal ligament space, i.e., to the degree of horizontal tooth mobility.

Conditions and pathological features of rapidly destructive, experimental periodontitis in dogs.

In order to analyze the conditions for rapidly destructive periodontitis and to describe the early histopathological changes and bone degradation, periodontitis lesions were produced in five male Beagle dogs, 8 to 12 months of age. Cotton floss ligatures were placed around the crowns of upper and lower third and fourth premolars for periods of 4, 7, 14, 21 days. The buccal gingival tissues, being slightly inflamed initially, were clinically scored for various symptoms of inflammation. Block biopsies of premorlars and the adjacent buccal periodontal tissues were taken and processed for light and electron microscopy. Depending on the ligature position in relation to the gingival margin (above, at, deep below) at the day of biopsy harvest, three groups of selected biopsies were formed, and randomly selected sections of these were used for various histometric measurements, for stereological estimation of the size and composition of the connective tissue infiltrate and the osteoclast density, and for general histopathological evaluation. The resulting data and observations implied that (1) onset and maintenance of this periodontitis lesion depend on subgingival ulceration, (2) rapid bone desstruction is the result of osteoclast activity stimulated by acute inflammation, and (3) bone degradation occurs independently of the loss of collagen fiber attachment and the apical migration of the junctional epithelium.

The effect of levamisole on experimental gingivitis in the beagle dog.

The effect of Levamisole on gingivitis development was studied in three beagle dogs. Plaque accumulation was first allowed on one side of the jaws whereas the other side was subjected to careful tooth cleaning procedures. After 2 weeks' experimental gingivitis the dogs were given Levamisole and plaque accumulation was permitted on the other side of the jaws for another two weeks. The following parameters were investigated in the two gingivitis experiments: Plaque and Gingival Indices, Gingival Exudate measurements and histologic measurements. The biopsies were prepared both for light and electron microscopy. The clinical parameters did not show any differences between the two gingivitis experiments. The biopsies, however, demonstrated a larger area of infiltrated connective tissue and an increased number of leukocytes in the junctional epithelium in Levamisole-treated compared to normal animals.

Suppression of inflammation and bone resorption by indomethacin during experimental periodontitis in dogs.

1. The placement of cotton floss ligatures in a position apical to the gingival margin of premolars and molars in young dogs induced an acute inflammatory reaction in the periodontal tissues resulting in loss of connective tissue attachment and alveolar bone. 2. Bone resorption could be observed histologically within 7 days, and radiographically within 2 to 3 weeks after ligature placement. 3. Daily administration of indomethacin interfered with the periodontal tissue response to ligature placement. Indomethacin was shown to (i) delay the onset and to suppress the magnitude of the acute inflammatory reaction, and (ii) decrease the degree of alveolar bone resorption.

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.

Bone and soft tissue integration to titanium implants with different surface topography: an experimental study in the dog.

The aim of the present experiment was to study the peri-implant soft and hard tissues formed at titanium implants with 2 different surface configurations and to give a topographic description of the surfaces examined. In 5 beagle dogs, the mandibular premolars were extracted. Three months later, 4 self-tapping standard implants (SI) and 4 Osseotite implants (OI) of the 3i Implant System were placed. The marginal 3 mm of the OI is turned, while the remaining part has an acid-etched surface structure. Abutments were connected after 3 months. A plaque control period was initiated, and after 6 months block biopsies were obtained. From each animal 2 units of each implant type were processed and embedded in EPON. The remaining biopsies were processed for ground sectioning. The histometric measurements performed on the EPON sections revealed that the peri-implant soft tissues and the marginal level of bone-to-implant contact were similar for SI and OI sites. In the ground sections, bone-to-implant contact (BIC%) and bone density assessments were made in 2 different zones. Zone I represented the contact area measured from the marginal level of bone-to-implant contact (B) to a position 4 mm above the apex of the implant, and zone II represented the apical 4 mm of the implant. For the SI sites, the BIC% was 56.1% in zone II and 58.1% in zones I + II. The corresponding figures for the 01 sites were 76.7% and 72.0%. The BIC% was significantly larger at OI than at SI sites. Bone density values were similar at the SI and OI sites.

Effect of oral hygiene instruction and professional toothcleaning on caries and gingivitis in schoolchildren.

The preset study was performed to assess the effect on caries and gingivitis of plaque control measures such as oral hygiene instruction, toothcleaning practice and professional toothcleaning. 104 children, 13-14 years old, participated in the trial. Prior to the start of the preventive treatment all children were examined regarding oral hygiene, gingivitis and caries. The caries examintion was limited to the proximal surfaces of molars and premolars. Following this baseline examination the children were randomly divided into two treatment groups A, and B. Both groups of children were recalled for professional toothcleaning once every 2 weeks during an 18-month period. In each child the professional toothcleaning was restricted to either the right or the left jaws by random selection. In addition, the children of Group A at each recall appointment received careful oral hygiene instruction and practice in proper toothcleaning methods. In conjunction with the professional toothcleaning an abrasive paste was used including fluoride. The children were re-examined 18 months after the baseline examination. The result of the present investigation demonstrated that professional toothcleaning repeated every second and week is a prophylactic measure which in children substantially improves the oral hygiene status, and effectively reduces clinical signs of gingivitis and caries. It was also observed that while oral hygiene instruction and practice in proper toothcleaning techniques reduced plaque and gingivitis, no such effect could be detected regarding the development of caries.

Effect of fluoride on gingivitis and dental caries in a preventive program based on plaque control.

The purpose of the investigation was to estimate the relative effect of fluoride on caries in a preventive program based on meticulous plaque control. The material consisted of 82 children; 41 in the test and 41 in the control group. At the start of the study the children were 13-14 years of age. In August 1973 an examination was performed to obtain baseline data for the trial. Prophylactic treatment was given to the children once every second week. A total of 18 treatments were given during a 10-month period. In the control group an abrasive paste was used containing 5% sodium monofluorophosphate (Jodka Fluor Polerpasta). In the test group an abrasive paste was used which was identical with the control paste except that it did not contain any fluoride components. Twelve months after the baseline examination the test and control groups were reexamined. The trial demonstrated that, in children, fortnightly professional cleaning of the teeth combined with meticulous toothbrushing instructions result in (1) a high standard of oral hygiene and (2) only very few new carious surfaces. Though the control group children received fortnightly topical application of F- during the prophylactic sessions and used a fluoridated dentifrice, there was no significant difference between the two groups regarding number of new carious tooth surfaces per child per year.

Effect of proper oral hygiene on gingivitis and dental caries in Swedish schoolchildren.

The present paper reports the effect of a 3-year study of regularly repeated professional toothcleaning on oral hygiene status, gingivitis, and dental caries. At the initiation of the study in 1971, the children were 7-8 years old (Group 1), 10-11 (Group 2) or 13-14 (Group 3). The children were divided into test and control groups. Before the study all the children were examined regarding oral hygiene, state of the gingiva and dental caries. Throughout the 3-year period the controls brushed their teeth with a 0.2% sodium fluoride solution once a month under supervision. During the first 2 years of the trial all the children of the test groups were given professional oral prophylaxis once every second week during the school terms. During the third year the interval between consecutive prophylactic sessions was prolonged to 4 weeks in Groups 1 and 2 and to 8 weeks in Group 3. The results demonstrated that regularly repeated professional cleaning of the teeth combined with fluoride applications and toothbrushing instructions, over a 3-year period in schoolchildren resulted in the establishment and maintenance of excellent oral hygiene standards. Inflammation of the marginal gingiva almost entirely disappeared, and practically no new carious lesions developed.

The effect of various plaque control measures on gingivitis and caries in schoolchildren.

The aims of the present study were (1) to analyze the separate effects on plaque, caries, and gingivitis of several measures (oral hygiene instruction, professional tooth cleaning with mechanical instruments, topical application of sodium monofluorophosphate - MFP) which have been incorporated in a prophylactic treatment program, described by AXELSSON & LINDHE1, and (2) to prevent caries and gingivitis by applying the combined treatment but replacing the professional mechanical tooth cleaning with chemical cleaning using a chlorhexidine-containing gel. 164 children, 13-14 years old, divided into four groups, participated in a 2-year trial. All participants were recalled once every 2nd week for preventive treatment provided by dental nurses. During the 1st year Group 3 and 4 received prophylactic treatment identical to that described by AXELSSON & LINDHE1. During the 2nd year the professional tooth cleaning was omitted but oral hygiene instruction was given every 2nd week. During the 1st year Groups 1 and 2 were treated with 0.5% chlorhexidine but during the 2nd year they were subjected to professional tooth cleaning with mechanical instruments. Throughout the trial Groups 1 and 3 rinsed once every 2nd week with a 2% MFP solution. The results showed that by oral hygiene instruction and frequently repeated professional tooth cleanings it was possible to substantially reduce the frequency of gingivitis and prevent caries. When this treatment was used, mouthrinsings with 2% MFP had no additional effect on caries. The substitution of the mechanical cleaning procedure with topical application of a 0.5% chlorhexidine gel failed to (1) remove supragingival plaque accumulations, (2) reduce the frequency of gingivitis, and (3) retard the rate of caries development. The data also revealed that interdental cleaning with mechanical instruments was of decisive importance in the prevention of approximal surface caries.

Effect of a field program based on systematic plaque control on caries and gingivitis in schoolchildren after 3 years.

The effect of a field program, based on systematic plaque control, on caries and gingivitis was tested during a 3-year period on 1,100 schoolchildren. Once every 3rd week the children were given oral hygiene instructions, professional toothcleaning and fluorides topically delivered by specially trained dental nurses. The children of a control group of approximately the same number of pupils, participated in a preventive program consisting of mouthrinsings once every 2nd week with a 0.2% sodium fluoride solution. The children of the third and fourth grades were, at the start of the experiment, selected as reference groups and then continuously examined once every year. At the end of the trial the mean reduction of surfaces haboring plaque and units with gingival inflammation was 59% and 73%, respectively. The reduction in caries increment was 51%.

Marginal tissue reactions at osseointegrated titanium fixtures (I). A 3-year longitudinal prospective study.

16 consecutive totally edentulous patients were provided with 95 osseointegrated titanium fixtures in 7 upper and 9 lower jaws. Facultatively removable bridges were later connected to abutments, attached to the fixtures. The marginal soft and hard tissue reactions were investigated at a baseline examination and after 6, 12, 21, 30 and 39 months by standardized clinical and radiographical methods. At the last examination, microbiological samples and gingival biopsies were also analysed. The % ratios of abutments without plaque, 70-75%, and without any gingivitis, 80-85%, were almost constant throughout the study. The mean probing depth was 2.9 mm at the final examination. About 75% of all probing depths were 3 mm or less and none exceeded 5 mm. The bridge-gingiva distances increased during the investigation. Attached gingiva surrounded 65% of the buccal and lingual abutment surfaces. Only 0.9 mm marginal bone was lost as a mean during the first year and not more than 0.05 mm annually for the next 2 years. After 6 months, no significant changes in marginal bone levels occurred. The perifixtural bone gradually became more radiopaque, especially marginally in upper jaws, indicating a successive load-related remodelling. The microbiotia comprised coccoid cells and non-motile rods to 93% in 32 samples. Healthy tissues were present in 35% of the 14 soft tissue biopsies. In a further 29%, only a slight inflammation was observed. No constant correlations could be established for any of the investigation parameters used. It is concluded that the marginal soft tissue reactions were mild and not significant for a progressive periodontitis. Mobility tests of separate fixtures combined with quantitative and qualitative standardized radiological examinations of the surrounding bone appear to provide a truer comprehension of longitudinal events at osseointegrated implants than conventional clinical soft tissue observations. The prognosis for the osseointegrated implants appears excellent, especially with regard to the microbiotia, the small marginal bone height changes, and the radiological indications of remodelling in the perifixtural bone.

Marginal tissue reactions at osseointegrated titanium fixtures. (II) A cross-sectional retrospective study.

20 totally edentulous patients, provided with 24 facultatively removable fixed bridges (13 upper and 11 lower jaws) were recalled. The material consisted of 125 osseointegrated titanium fixtures with a mean observation time of 7.6 years (range 6 months to 15 years). The marginal tissues were examined by conventional periodontal clinical methods and standardised radiography. Microbiological samples and biopsies of the soft marginal barrier tissues were retrieved for dark-field and histological analysis, respectively. The percental ratios of abutment surfaces devoid of plaque and without signs of gingivitis, were 46% and 20%, respectively. In contrast to earlier studies, the presence of plaque and gingivitis was significantly correlated. This relationship was probably due to more plaque being present. The mean probing depth was 3.8 mm. In 40% of the measurements, the probing depths were 3 mm or less, and in 45% between 4 and 5 mm, whereas they only in 15% were 6 mm or more. They were greater in upper than in lower jaws and were found to be significantly correlated with gingivitis. Attached gingiva surrounded about 51% of the buccal and lingual abutment surfaces. The marginal bone height changes were very small during the follow-up period (0.07 mm annually). Coccoid cells and non-motile rods dominated the microflora to 94% in the 48 samples taken. Out of the 19 biopsies, 58% showed healthy mucosa and a further 37% had the lowest inflammation score. The indications of gingivitis and deep pockets at the clinical examination were not found accompanied by an accelerated marginal bone loss, nor by a microflora or histological changes indicative of periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Some anatomical features of the periodontium of the deciduous and permanent dentition in the beagle dog.

The present study describes some anatomical characteristics of teeth and periodontal tissues in the deciduous and permanent dentition of the beagle dog. Five animals were used. At the age of 10 weeks (Period A) and 15 months (Period B), respectively, a plaque control period was initiated. At the end of each plaque control period, clinical examinations were performed. Biopsies were obtained from the 02P, 03P (Period A) and P3, P4 (Period B) tooth regions and were examined with the light microscope. Histometric and morphometric measurements were made. The macroscopic and microscopic measurements revealed that marked differences exist between the teeth and the periodontium of the deciduous and the permanent dentition. The permanent premolar erupting into the position of the deciduous premolar was found to be significantly wider and higher than its precursor. Also the shape of the crown of the permanent premolar differed from that of the deciduous premolar. The sinuous contour of the buccal gingival margin was more accentuated in the deciduous than in the permanent dentition. The free gingiva was shorter and the periodontal ligament space was wider in the deciduous than in the permanent dentition. The free gingival unit in the deciduous dentition consisted of a larger volume of epithelium and a smaller volume of connective tissue than the corresponding unit in the permanent dentition. The connective tissue of the deciduous gingiva contained a larger proportion of fibroblasts and a lower proportion of collagen fibres than the corresponding tissue of the permanent gingiva.

Marginal tissue reactions at osseointegrated titanium fixtures.

A longitudinal prospective and a cross-sectional retrospective study were undertaken in order to investigate the marginal tissue reactions at osseointegrated titanium fixtures and their abutments, supporting fixed bridges. Conventional clinical periodontal examination methods were combined with a serial-identical radiography. At the termination of the studies samples were taken for microbiological and histological analyses. Altogether the reactions at 220 fixtures in 40 jaws were explored. The clinical parameters were not found correlated with the other examination methods. Only 0.9 mm marginal bone was lost as a mean during the first year and then not more than 0.05-0.07 mm as a mean annually for the follow-up years. A stress-related remodelling of the perifixtural bone was observed radiographically. The microbiotia in the gingival pockets was dominated by cocci and non-motile rods (94%), indicating a favourable composition if similar findings had been observed at teeth. Half the number of the biopsies had no inflammatory infiltrates and a further third had the lowest inflammatory score in a 3-grade scale. The results indicate that the soft tissue surrounding the gingival part of osseointegrated fixtures remains remarkably healthy, which, in combination with the annual minor loss of marginal bone, is an indication of good long-term clinical prognosis.

Current concepts in diagnosis and treatment of periodontitis.

This article describes some areas of periodontal research and current opinions regarding detection of disease progression, as well as risk indicators and risk factors associated with disease progression. Longitudinal probing of periodontal attachment level is considered the gold standard for detection of disease activity although there are problems with this concept. Digital subtraction radiography can assist in the detection of minor changes of alveolar bone height and density. Risk factors such as composition of subgingival plaque and gingival crevicular fluid, as well as the effect of smoking are discussed. Adjunctive treatment with both antibiotics and nonsteroidal anti-inflammatory drugs, systemic or local, seems to be helpful in some forms of disease. Immunization to prevent colonization of tooth surfaces and pockets by periodontal pathogens does not seem to be feasible in the near future.