Search PubMed⌕ Search

Biomedical subjects

S Nyman

Publications and source records attributed to S Nyman.

At least 127 records · Page 7Linked to original sources
PubMed1980

Healing following implantation of periodontitis affected roots into bone tissue.

The aim of the present experiment was to study whether new connective tissue attachment can occur to root surfaces which have been exposed to the oral environment and subsequently implanted into bone tissue. Twelve teeth in three beagle dogs were subjected to progressive periodontal breakdown to half the root length by placing cotton floss ligatures around the neck of the teeth. Following crown resection and root hemisection, the teeth were root filled and the roots thoroughly scaled and planed. Each root was extracted and implanted into bone cavities prepared in edentolous areas of the jaws in such a way that epithelial migration into the wound and bacterial infection were prevented during healing. Root implantation and sacrifice of the animals were scheduled to allow for observation periods of 1, 2 and 3 months. The results demonstrated that new connective tissue attachment did not occur to root surfaces which had been exposed to the oral environment, but healing was characterized by repair phenomena, i.e. mainly root resorption and ankylosis. In those areas of the roots where periodontal ligament tissue was preserved following tooth extraction, a functionally oriented attachment apparatus was reformed. The results indicate that in addition to apical migration of junctional epithelium and regrowth of subgingival plaque, the type of cells which repopulate the wound area may jeopardize new connective tissue attachment.

Animals↗
PubMed1980

Histometric evaluation of periodontal surgery. I. The modified Widman flap procedure.

The present investigation was performed in the Rhesus monkey to determine the effect of the modified Widman flap procedure on the level of the connective tissue attachment and supporting alveolar bone. Two adult male Rhesus monkeys were used. Eighteen contralateral pairs of periodontal pockets were produced in a standardized manner. Surgical treatment of the pockets was performed around experimental teeth and the contralateral teeth were used as the unoperated controls. Twelve months following treatment the animals were sacrificed and histological sections obtained. Using the cemento-enamel junction (CEJ) as a fixed reference point, linear measurements along the root surface were made to the most apical cells of the junctional epithelium (JE), to the crest of the interproximal alveolar bone (CR), and to the apical extent of angular bony defects (AAD). These measurements from operated and unoperated pockets were then compared. The data revealed that treatment of periodontal pockets using the modified Widman flap procedure produced no gain in connective tissue attachment and no increase in crestal bone height. In angular bony defects a certain degree "bone fill" was noted. This bone repair was never accompanied by new connective tissue attachment.

Alveolar Process↗
PubMed1980

Histometric evaluation of periodontal surgery. II. Connective tissue attachment levels after four regenerative procedures.

The present study was undertaken to determine the effect of four periodontal regenerative procedures on the connective tissue attachment level. The procedures tested were: 1) the modified Widman flap procedure, 2) the modified Widman flap procedure combined with transplantation of previously frozen autogenous red marrow and cancellous bone, 3) the modified Widman flap procedure in combination with implantation of beta tricalcium phosphate, and 4) periodic root planing and soft tissue curettage. Eight adult Rhesus monkeys, divided into four equal groups, were used. Periodontal pockets were produced around contralateral teeth in a standardized manner. In each group of animals, the pockets on one side of the jaws were subjected to one of the above-mentioned surgical treatments, while the contralateral pockets remained as unoperated controls. Three weeks before surgery, a carefully designed plaque control program was instituted and continued until the animals were sacrificed 12 months after surgery. In histologic sections, linear measurements along the root surfaces were made from the cemento-enamel junction (CEJ) to the most apical cells of the junctional epithelium (JE). These measurements from operated and unoperated sites were then compared. The data revealed that healing following the four different regenerative procedures resulted in the reformation of an epithelial lining (long junctional epithelium) along the treated root surfaces, with no new connective tissue attachment.

Alveoloplasty↗
PubMed1980

Healing following implantation of periodontitis-affected roots into gingival connective tissue.

The aim of the present investigation was to examine if a new connective tissue attachment can be established on a previously periodontitis involved root surface, located in contract with gingival connective tissue during healing. A total of 28 teeth in one dog (beagle) and two monkeys (Macaca cynomolgus) were subjected to experimental periodontal tissue breakdown by placing cotton floss ligatures or orthodontic elastics around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following resection of the crowns, the teeth were root filled and the exposed parts of the roots thoroughly scaled and planed. Each root was extracted and implanted into grooves prepared in edentulous areas of the jaws in such a way that the root was embedded to half its circumference in bone, leaving the remaining part to be covered by the gingival connective tissue of the repositioned flap of the recipient site. Root implantation and sacrifice of the animals were scheduled to allow for observation periods of 2 and 3 months of healing. An analysis of histologic specimens, obtained from biopsies of the recipient site tissues, disclosed that a new fibrous attachment failed to form on a previously "exposed" root surface located in contact with gingival connective tissue. In areas of the roots where the periodontal ligament tissue was preserved prior to transplantation, a fibrous reattachment occurred between the root and the adjacent gingival tissue. The results indicate that gingival connective tissue does not possess the ability to establish conditions which enable the formation of a new connective tissue attachment.

Alveolar Process↗
PubMed1980

Alterations of the position of the marginal soft tissue following periodontal surgery.

The present study was performed to examine the alterations of the position of the marginal soft tissue ("gingival margin") on the buccal surface of teeth in patients who following periodontal surgery were enrolled in a supervised maintenance care program for 10--11 years. The material consisted of 43 patients with severe destruction of the periodontal tissues. Following initial treatment comprising scaling, root planing and instructions in plaque control measures, deepened periodontal pockets were eliminated by the use of an apically repositioned flap procedure including osseous surgery to eliminate bony defects. After treatment, the patients were recalled once every 3--6 months for maintenance care. In all patients, the distance between the cemento-enamel junction and the gingival margin on the buccal surfaces of all treated teeth was assessed (1) prior to surgery, (2) after initial healing, and (3) at a reexamination 10--11 years after treatment. In addition, the presence or absence of keratinized gingiva was determined. The results showed that (1) during active periodontal treatment the position of the gingival margin was shifted in an apical direction, (2) this displacement was to some extent compensated for by a coronal regrowth during the postoperative maintenance care period, (3) the alterations of the position of the gingival margin followed a similar pattern in areas with and without a zone of keratinized gingiva, (4) the number of gingival units devoid of keratinized gingiva decreased during the maintenance care period.

Adult↗
PubMed1979

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.

Alveolar Process↗
PubMed1977

Periodontal surgery in plaque-infected dentitions.

A clinical trial was performed to study the result of periodontal treatment following different modes of periodontal surgery in patients not recalled for maintenance care. The material consisted of 25 patients distributed into 5 groups. Following an initial examination, all patients underwent presurgical treatment including case presentation and instruction in oral hygiene measures. This instruction was given once. The various patient groups were then subjected to one of the following surgical procedures: 1) the apically repositioned flap operation including elimination of bony defects 2) the apically repositioned flap operation including curettage of bony defects but without removal of bone 3) the "Widman flap" technique including elimination of bony defects 4) the "Widman flap" technique including curettage of bony defects but without removal of bone 5) gingivectomy including curettage of bony defects but without removal of bone. Six, 12 and 24 months after completion of the treatment, the patients were recalled for assessment of their oral hygiene standard and periodontal conditions. The results showed that case presentation and oral hygiene instruction given once, only temporarily improved the patient's oral hygiene habits. Renewed accumulation of plaque in the operated areas resulted in recurrence of periodontal disease including a significant further loss of attachment. All five different techniques for surgical pocket elimination were equally ineffective in preventing recurrence of destructive periodontitis.

Adult↗
PubMed1977

A clinical study of the relationship between crowding of teeth, plaque and gingival condition.

A clinical trial was undertaken to assess whether crowded teeth were more likely to accumulate plaque and develop gingivitis than non-crowded teeth. A tooth was considered crowded if it was displaced by 2 mm and/or rotated 15 degrees or more from the normal position in the arch. The material consisted of 50 dental students aged 21 to 32 years. An initial examination comprised assessment of Plaque Index, Gingival Index and pocket depths. After this examination the subjects refrained from using interdental cleaning aids but continued with their normal toothbrushing for 40 days. After re-examination they were instructed in the effective use of dental floss. A final examination was carried out after 140 days. At the start of the trial no difference was found in regard to the Plaque Index between crowded and non-crowded teeth. The Gingival Index for growded front teeth, but not for crowded premolars, was somewhat higher than for the corresponding controls. The cessation of interdental cleaning resulted in a similar increase in plaque accumulation and gingival inflammation in both non-crowded and crowded teeth. The use of dental floss for approximal tooth cleaning resulted in a similar decrease in the Plaque- and Gingival Indices for both types of teeth. The results demonstrate that in a group of young adults, crowding of teeth (1) did not favour plaque accumulation on approximal tooth surfaces and (2) influenced the degree of gingival inflammation only to a minor extent.

Adult↗
PubMed1976

The healing potential of the periodontal tissues following different techniques of periodontal surgery in plaque-free dentitions. A 2-year clinical study.

A clinical trial was undertaken to study the healing capacity of the periodontal tissues following different modes of periodontal surgery in patients whose oral hygiene was professionally maintained at an optimal level. Fifty patients, distributed into five groups, participated in the study. Following an initial examination and presurgical treatment, the various patient groups were subjected to one of the following surgical procedures: 1) the apically repositioned flap operation including elimination of bony defects, 2) the apically repositioned flap operation including curettage of the bony defects but without removal of bone, 3) the "Widman flap" technique including elimination of bony defects, 4) the "Widman flap" technique including curettage of the bony defects but without removal of bone, 5) gingivectomy including curettage of the bony defects but without removal of bone. After surgery, all patients received oral hygiene instruction and professional cleaning of the teeth once every 2 weeks during a 2-year period. The results showed that periodontal disease can be cured and further destruction of the periodontal tissues avoided irrespective of the surgical technique utilized for pocket elimination. Different surgical techniques, however, promoted varying degrees of regeneration of the supporting tissues. The most favourable healing was obtained when resection of bone was avoided and when complete coverage of the alveolar bone was ensured.

Adult↗