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Biomedical subjects

S Nyman

Publications and source records attributed to S Nyman.

At least 73 records · Page 4Linked to original sources
PubMed1987

Guided tissue regeneration in the treatment of furcation defects in man.

The regenerative potential of the periodontal tissues in degree II and III furcation defects at mandibular molars was assessed in a clinical trial using a surgical treatment technique based on the principles of guided tissue regeneration. The patient sample included 37 subjects who had periodontal lesions in the right and left mandibular molar regions, including advanced periodontal destruction within the radicular area. Following a baseline examination, the furcation-involved molars were randomly assigned in each patient to either a test or a control treatment procedure. The test procedure included the elevation of mucoperiosteal flaps and the placement of a teflon membrane to cover the entrance of the furcation area and the adjacent root surfaces as well as a portion of the alveolar bone apical to the crest. The flaps were repositioned and secured with interdental sutures. A procedure identical to the one used at the test teeth was performed at the control tooth regions with the exception of the placement of the teflon membrane. Following surgery, all patients were placed on a plaque control regimen which involved daily rinsing with chlorexidine gluconate and, in addition, professional tooth cleaning once every 2 weeks for 6 months. After 6 months of healing, the test and control sites were re-examined. The findings demonstrated that the treatment of degree II furcation defects at mandibular molars using the principles of guided tissue regeneration in 19 sites out of 21 resulted in the resolution of the furcation defect. Conventional therapy reached the same goal in less than 20% of the cases treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Connective Tissue↗
PubMed1987

Periodontal status and bruxism. A comparative study of patients with periodontal disease and occlusal parafunctions.

This study investigated a possible association between bruxism and severity of periodontal disease. Subjects consisted of 51 patients (mean age 47.3 years) referred to the Department of Periodontology for treatment of moderate to severe periodontal disease (Perio-group) and 40 patients (mean age 48.9 years) referred to the Department of Stomatognathic Physiology for treatment of symptoms related to bruxism (Bruxism-group). Examination of the two groups included measurements of the alveolar bone height, probing attachment level, tooth mobility, and attrition of teeth. A questionnaire was also used to gain information on the patient's awareness of bruxism and tooth mobility. Awareness of clenching and/or grinding was reported by 57% of patients in the Bruxism-group and 24% of patients in the Perio-group. The perio-patients reported significantly higher frequency of tooth mobility than did the bruxism-patients. Alveolar bone loss, attachment loss, and tooth mobility were significantly more pronounced in the Perio-group than in the Bruxism-group. The Bruxism-group showed a higher frequency of tooth attrition than the Perio-group. Periodontal disease and bruxism seldom occurred in the same individual, and the results indicate that the two phenomena are in general not closely associated.

Adult↗
PubMed1987

Periodontal regeneration via selective cell repopulation.

The purpose of this investigation was to determine the histogenesis of periodontal regeneration using the principle of selective and guided cell repopulation of the root surface. A fenestration model, developed in the squirrel monkey, made it possible to exclude gingival epithelium and connective tissue and promote cell repopulation of the denuded root surface from the periodontal ligament and alveolar bone. Experimental and sham-operated control sites were compared histometrically after 3, 7, 14 and 35 days of healing. The results indicated that new cementum, bone and periodontal ligament formation occurred by the 14th day and that regeneration of the fenestration wound was almost complete by Day 35. Root resorption and ankylosis were observed in both experimental and sham-operated controls. There was significantly more periodontal regeneration in the experimental sites, which favored cell repopulation of the root surface from the periodontal ligament and alveolar bone.

Alveolar Process↗
PubMed1986

New attachment formation in the human periodontium by guided tissue regeneration. Case reports.

The aim of the present study was to evaluate whether a regenerative surgical procedure, based on guided tissue regeneration, could predictably result in the formation of a new attachment in human teeth. The material included 12 teeth in 10 patients with advanced periodontal disease. Following flap elevation, scaling, root planing and removal of granulation tissue, a teflon membrane was placed over the denuded root surface in such a way that the epithelium and the gingival connective tissue were prevented from reaching contact with the root during healing. The flap was replaced on the outer surface of the membrane and secured with interdental sutures. This design of wound preparation gives preference to the cells originating from the periodontal ligament (PDL-cells) to repopulate the wound area adjacent to the root. Histologic analysis of the result of treatment was made in 5 of the 12 teeth scheduled for extraction. In the remaining 7 teeth, the result was evaluated using clinical measurements. The result of healing disclosed that in all teeth treated, substantial amounts of new attachment had formed. This suggests that predictable restitution of the attachment apparatus can be accomplished by using a method of treatment which is based on the principle of guided tissue regeneration.

Adult↗
PubMed1986

Treatment of localized gingival recessions with coronally displaced flaps and citric acid. An experimental study in the dog.

The present study was designed to examine the effect of citric acid conditioning on the result of healing following treatment of localized gingival recessions with coronally displaced flaps. In 3 beagle dogs, localized gingival recessions were surgically created at the buccal surfaces of canines, premolars and molars. All experimental sites were allowed to accumulate plaque for a period of 6 months. Following preparation of notches in the buccal root surfaces at the level of the gingival margin, buccal and lingual mucoperiosteal flaps were raised. The exposed portion of the root surfaces was scaled and the cementum layer was removed. Another notch was prepared in the root surfaces at the level of the crest of the alveolar bone. Half the number of the roots were treated by topical application of citric acid while the remaining roots were used as non-acid treated controls. The flaps were sutured in a coronally displaced position. After 3 months of healing, the dogs were sacrificed and the jaws removed and placed in fixative. After decalcification, histological sections of the experimental roots and their periodontal tissues were produced. The 2 notches described above were used as reference points in the histological examination. The histological analysis disclosed that new attachment had formed on all test and control roots and extended in some specimens of both groups to a position coronal to the presurgical level of the gingival margin. The amount of new attachment was similar in the 2 categories of roots, demonstrating that citric acid conditioning did not produce additional new attachment.

Animals↗
PubMed1986

The significance of coronal growth of periodontal ligament tissue for new attachment formation.

The present study was designed to examine whether coronal growth of granulation tissue originating from the periodontal ligament is a prerequisite for new attachment formation. In each of 4 monkeys, 1 central incisor and 2 first molars in the maxilla and the mandible were selected for experimentation. Angular bony defects were surgically produced to the mid-root level around each single root after crown resection and root separation of the multirooted teeth. The periodontal ligament tissue and the root cementum were removed to the bottom of the bony defects. In half the number of the teeth, an elastic ligature was placed tightly around each root at the bottom of the defects (test roots). In the remaining teeth, an elastic ligature was placed loosely around each root at the same level (control roots). All roots were subsequently covered by laterally displaced flaps. After 3 months of healing, the animals were sacrificed and the jaws removed and placed in fixative. Following decalcification, histological sections of the experimental roots and their surrounding periodontal tissues were produced. The histological analysis disclosed that new attachment had former to a level coronal to the elastic ligature in 10 of 14 control roots but in only 1 of 18 test roots. The results indicate that the repopulation of a detached root surface by cells from the periodontal ligament is a prerequisite for new attachment formation.

Animals↗
PubMed1986

A clinical evaluation of fixed-bridge restorations supported by the combination of teeth and osseointegrated titanium implants.

The present paper reports on the result of the use of osseointegrated titanium fixtures and teeth as combined abutments for fixed-bridge restorations in 10 partially dentate patients. In these patients, the remaining teeth were too few or too unfavourably distributed in the jaws to serve as sole abutments for fixed bridgework. Titanium fixtures ad modum Brånemark were therefore implanted in suitable positions and used as abutments in combination with the remaining teeth. Evaluations at periods of 6 to 30 months postoperatively revealed good clinical results. Some tissue reactions, however, were also observed, indicating the presence of certain clinically significant differences in the functional behaviour of tooth abutments and titanium fixture abutments. These reactions and differences are discussed.

Adult↗
PubMed1985

Scaling and granulation tissue removal in periodontal therapy.

The present clinical trial was performed to study whether subgingival scaling is a method of therapy which is equally effective as "access" flaps in reducing gingivitis and probing depths and in improving probing attachment levels. The study was also designed to assess whether granulation tissue removal is a determining factor for proper healing in the treatment of periodontal disease. 15 patients with advanced periodontal disease were included in the study. Each patient had at least 4 sites in each quadrant of the jaws with probing depths exceeding 6 mm. A baseline examination was performed to assess the following parameters: the oral hygiene status, the gingival conditions, the probing pocket depths and the probing attachment levels. In addition, in each quadrant, 3 approximal sites were selected for analysis of the subgingival microbiota. All of these sites showed signs of gingivitis. One site had a probing depth of less than 4 mm, another a probing depth between 4 and 6 mm and the third site had a probing depth exceeding 6 mm. The subgingival bacterial samples were studied by dark-field microscopy and the % of spirochetes and motile rods was assessed. By random selection the 4 jaw quadrants in each patient were treated for periodontal disease by the use of (1) the modified Widman flap procedure, (2) the modified Kirkland flap procedure or by (3) nonsurgical scaling and root planing. In all, 20 quadrants were treated with each of the 3 procedures. After the termination of active periodontal treatment, all patients were recalled for professional tooth cleaning once every 2 weeks during a 12-week period. Subsequently, they were recalled for prophylaxis every 3 months. The patients were examined 6 and 12 months after treatment using the same parameters as used at baseline. The data from the examinations demonstrated that subgingival scaling is an effective measure in the treatment of periodontal disease. Both in terms of average gingivitis resolution and average probing depth reduction, non-surgical therapy appeared to be equally effective as a surgical approach to treatment. It was also observed, however, that following non-surgical treatment, a larger number of sites with pockets exceeding 6 mm remained than following surgical therapy. Most of these deep pockets in non-surgically treated quadrants bled on probing to the base of the pocket. In addition, the subgingival microbiota of such sites were found to harbor more than 20% spirochetes and motile rods.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

New attachment formation on teeth with a reduced but healthy periodontal ligament.

The present investigation was undertaken to examine whether a new connective tissue attachment will form on previously periodontitis-involved roots when reduced but healthy periodontal ligament tissue persists following periodontal treatment and the epithelium is prevented from migrating into the wound. In each of 4 monkeys, periodontal tissue breakdown was induced around one maxillary and one mandibular second premolar or first molar by placing orthodontic elastics around the teeth. The elastics were kept in situ until about 50% of the supporting tissues had been lost. 3 months following removal of the elastics, the crowns of the teeth were resected. The pocket epithelium and subjacent granulation tissue were excised and the cementum of the periodontitis-involved part of the roots was removed using a diamond bur. The roots were covered with a mucosal flap. The animals were sacrificed after 3 months of healing. The jaws were removed and histological sections of the experimental roots including their surrounding periodontal tissues were produced. The microscopic analysis disclosed that in all roots, new cementum with inserting collagen fibers had formed in the apical portion of the previously exposed root surfaces. It was always in continuity with the original cementum layer apical to the instrumental part of the root and was thickest in its apical portion, becoming gradually thinner in the coronal direction. In the roots, which for the entire length of the study remained covered by the oral mucosa, the extension in the coronal direction of this newly formed fibrous attachment amounted to an average of 1.0 mm with a range from 0.1 mm to 2.6 mm. These findings were interpreted to mean that new attachment is formed by coronal migration of cells originating from the periodontal ligament.

Animals↗
PubMed1985

Healing after root reimplantation in the monkey.

The aim of the present investigation was to evaluate the regenerative potential of the periodontal tissues following tooth reimplantation using a model which excluded the dentogingival epithelium from the process of healing. Maxillary and mandibular incisors, premolars and molars of 5 monkeys were used. Following root filling of all experimental teeth, the teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted following the elevation of full thickness flaps. The crowns were separated from the roots at the level of the buccal cemento-enamel junction and the roots immediately reimplanted into their sockets. The flaps were replaced and sutured to accomplish complete coverage of the roots. In a 2nd group, the teeth were subjected to the same experimental procedure, but in addition, the buccal alveolar bone was removed to about half its original height prior to root reimplantation. The teeth of the 3rd group were subjected to identical experimental procedures as for group II with the addition that the buccal root surfaces were planed to the level of the surgically created bone crest. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. The results showed that a complete fibrous re-attachment formed onto roots on which the original periodontal ligament tissue was preserved. This occurred irrespective of whether the roots were reimplanted into sockets with normal (group I) or reduced (group II) bone height. When the original periodontal ligament tissue was removed by root planing before reimplantation (group III), healing resulted in a significant amount of new connective tissue attachment. However, coronal to the newly formed fibrous attachment, the root surface frequently showed signs of resorption and particularly so in those roots which remained covered by the soft tissue during the entire course of healing. In the majority of the roots which perforated the covering soft tissue during the early phase of healing, the dentogingival epithelium had migrated apically into contact with the coronally generated fibrous attachment. In these cases, root resorption was never discernible. New bone formation occurred to a variable extent in the roots of groups II-III. No relationship was found, however, between the amount of connective tissue reattachment or new attachment and newly formed alveolar bone, which in turn indicates that bone tissue regrowth and periodontal ligament regeneration are unrelated phenomena.

Alveolar Process↗
PubMed1985

New attachment-reattachment following reconstructive periodontal surgery.

The present study was designed to evaluate if the conditions for reformation of a connective tissue attachment are less favorable on root surfaces which have lost their fibrous attachment because of periodontal disease than on root surfaces surgically deprived of their attachment apparatus. In each of 4 Green monkeys, 2 maxillary and 2 mandibular teeth were selected for experimentation. Periodontal breakdown was produced and allowed to progress to the mid-root level around one of the experimental teeth in both the maxilla and mandible by placing elastic ligatures around the neck of these teeth. 3 months after removal of the ligatures, the crown of the teeth was resected and the epithelium and the subjacent granulation tissue were removed. Using a diamond bur, circumferential defects similar to those obtained by the ligature induced destruction were then produced around the remaining 2 experimental teeth following resection of the crown. The root cementum on both groups of teeth was removed to the level of the reduced bone height. Finally, all roots were submerged to complete coverage by a mucosal flap. After 3 months of healing, the animals were sacrificed and the jaws removed and placed in fixative. After decalcification, histological sections of the experimental roots and their surrounding periodontal tissues were produced. No histological differences in the result of healing were discernible between the specimens of previously periodontitis-affected roots and roots with surgically created defects. New cementum with inserting collagen fibers had formed in the apical part of the instrumented surface in both groups of teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effect of age on healing following periodontal therapy.

The present investigation was performed in order to analyze the effect of age on healing of the periodontal tissues following treatment. The patients included in the present analysis consisted of 2 different samples. One group of 62 patients (sample A) was examined and treated between 1980 and 1982. 13 of these subjects were less than 40 years of age, 26 subjects were 40-49 years of age and 23 subjects were greater than 49 years old. The patients were subjected to periodontal surgery using the modified Widman flap procedure. During the active phase of treatment and for the subsequent 6 months of healing, all 62 patients were subjected to professional tooth cleaning. Instruction in proper oral hygiene measures was repeated and scaling was carried out when indicated. Sample B consisted of 21 subjects treated for advanced periodontal disease in 1969. Six of these patients were between 26 and 29 years of age at the start of treatment and 15 were at least 60 years old. The criterion for acceptance for the study in 1969 was that the patient should have lost 50% or more of his/her periodontal tissues. Following an initial examination, all patients were subjected to scaling and root planing and surgical elimination of pathologically deepened pockets. After the termination of active treatment, the patients were placed in a maintenance care program which included recall appointments every 3-6 months. Once a year after the completion of active treatment, all patients in this sample were examined regarding probing depths and clinical attachment levels. The findings from the present retrospective analyses failed to demonstrate that the age of patients with moderately advanced or advanced forms of periodontal tissue breakdown had an influence on the results of periodontal therapy. If anything, the younger patients appeared to heal with a higher frequency of shallow pockets and more gain of probing attachment than older patients.

Adult↗
PubMed1985

Improved periodontal conditions following therapy.

The aim of the present clinical trial was to evaluate the effect of different modes of periodontal therapy on patients with moderately advanced periodontal disease and to express the findings in terms of probing pocket depth and attachment level alterations at periodontal sites with different initial probing depths. The material consisted of 16 patients, 35-65 years of age. Following a Baseline examination including assessments of oral hygiene status, gingival conditions, probing pocket depths and probing attachment levels, the patients were subjected to periodontal treatment. A "split-mouth" design approach of therapy was used and the jaw quadrants were randomly selected for the following different treatment procedures: (1) scaling and root planning, (2) scaling and root planing in conjunction with a gingivectomy procedure, (3) scaling and root planing in conjunction with an apically repositioned flap procedure without bone recontouring, (4) scaling and root planing in conjunction with an apically repositioned flap procedure including bone recontouring, (5) scaling and root planing in conjunction with a modified Widman flap procedure without bone recontouring and (6) scaling and root planing in conjunction with a modified Widman flap procedure including bone recontouring. The patients were following active treatment enrolled in a supervised maintenance care program including "professional tooth cleaning" once every 2 weeks during a 6-month period of healing, after which a final examination was performed. The investigation demonstrated that active therapy including meticulous subgingival debridement resulted in a low frequency of gingival sites which bled on probing, a high frequency of sites with shallow pockets (less than 4 mm) and the disappearance of pockets with a probing depth of greater than 6 mm. Between the Baseline examination and the 6-month re-examination, the probing attachment level for initially shallow pockets remained basically unaltered, but with a tendency of a minor apical shift. This occurred in all 6 treatment groups. For sites with initial probing depths of 4-6 mm and greater than 6 mm, there was in all groups some gain of probing attachment. This gain was most pronounced in the initially deeper (greater than 6 mm) pockets. With the use of regression analysis, the "critical probing depth" (CPD) value (i.e. the initial probing depth value below which loss of attachment occurred as a result of treatment and above which gain of probing attachment level resulted) was calculated for each of the 6 methods of treatment used. A comparison of the CPD-values between the 6 treatment groups did not reveal any major differences.

Adult↗