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Biomedical subjects

S Nyman

Publications and source records attributed to S Nyman.

At least 109 records · Page 6Linked to original sources
PubMed1983

Use of chlorhexidine as a plaque control measure following surgical treatment of periodontal disease.

Chlorhexidine mouth rinsing was compared with regularly performed professional tooth cleaning as a plaque control measure during healing following periodontal surgery. 14 patients were selected for the study. A Baseline examination included assessment of oral hygiene status, gingival condition, probing depth and attachment level. In each patient, scaling and root planing was carried out in conjunction with the modified Widman flap procedure including recontouring of alveolar bone irregularities in 2 jaw quadrants. The same procedures without osseous surgery were performed in contralateral jaw quadrants. 7 patients rinsed their mouth with a solution of 0.2% chlorhexidine digluconate twice a day, 2 min each time, for the first 6 months after therapy (healing phase). During the same period the remaining 7 patients were recalled every 2 weeks for professional tooth cleaning ad modum Axelsson & Lindhe (1974). Following reexamination after 6 months, all 14 patients were placed on a maintenance care program which included mechanical prophylaxis once every 3 months for 18 months (maintenance phase). Reexaminations were performed 6, 12 and 24 months after completion of initial therapy. The results revealed that professional tooth cleaning was somewhat more effective as a plaque control measure during healing following surgery than chlorhexidine mouth rinsing. At the end of the healing phase (1) there was a higher frequency of sites with pockets deeper than 4 mm in the patients who rinsed with chlorhexidine, (2) less gain of attachment occurred following chlorhexidine rinsing in pockets with an initial probing depth of greater than 4 mm, and (3) attachment loss in initially shallow pockets was somewhat more pronounced in the patients who rinsed with chlorhexidine. The differences in the effect of the 2 methods of plaque control, however, were small and in most respects diminished in the course of the maintenance phase. It was concluded that mouth rinsing with chlorhexidine is a proper alternative to plaque control during healing following periodontal surgery.

Adult↗
PubMed1982

The capacity of reduced periodontal tissues to support fixed bridgework.

The total area of periodontal ligament around the abutment teeth in 60 fixed bridges, inserted in patients treated for advanced periodontal disease, was calculated and compared with the total "periodontal ligament area" of the teeth replaced by pontics. The calculations revealed that only in 8% of the bridge restorations did the periodontal ligament area of the abutment teeth equal or exceed that of the replaced teeth. In 57% of the bridge material the periodontal ligament area of the abutments was less than 50% of the anticipated normal ligament area of the pontics. Despite the fact that the periodontal support for the restorations was dramatically reduced, all bridges have functioned properly for 8-11 years and the periodontal tissues around the abutment teeth have not suffered further loss of attachment during the period of maintenance care.

Denture, Partial, Fixed↗
PubMed1982

Scaling and root planing in shallow pockets.

The present study was undertaken to enable histological assessment of attachment level alterations following repeated scaling and root planing in periodontal sites with "normal" sulcus/pocket depth. Two monkeys (Macaca cynomolgus) were used. During a period of 6 months, scaling was carried out once every 2 weeks at the buccal surfaces of premolars and molars on the right side of the jaws. The contralateral teeth served as untreated controls. Six months after the completion of treatment (1 year after the start of the experiment), the animals were sacrificed and histological sections of all test and control teeth were produced. In these sections the distances between the cemento-enamel junction (CEJ) and the apical extent of the junctional epithelium (JE) and between the JE and the alveolar bone crest (BC) were measured. The results revealed that repeated scaling and planing resulted in an average loss of connective tissue attachment amounting to 0.39 mm and in a corresponding recession of the alveolar bone crest. The findings are discussed in relation to recent observations from clinical trials demonstrating loss of clinical attachment following repeated scaling and root planing in sites with shallow gingival pockets.

Animals↗
PubMed1982

The regenerative potential of the periodontal ligament. An experimental study in the monkey.

The aim of the present study was to examine if new cementum and new attachment may form during healing of a wound prepared in such a way that preference is given to periodontal ligament cells to repopulate the wound area adjacent to a root which has been surgically deprived of its periodontal ligament and cementum layer. The maxillary lateral incisors and mandibular canines in three monkeys were used for experimentation. Following elevation of a mucoperiosteal flap, the buccal and approximal alveolar bone was removed within an area extending from the mid-root level to a level 2 mm apical to the marginal bone crest. Following bone removal, the root surfaces were curetted in order to remove the cementum layer. Notches were prepared in the roots to demarcate the denuded root portion. Prior to repositioning of the tissue flap a millipore filter was placed over the treated area in order to prevent the gingival connective tissue from coming into contact with the root surface during healing. The animals were sacrificed 6 months after surgery. The jaws were removed and histological sections of the experimental teeth and surrounding periodontal tissues were produced. New cementum with inserting collagen fibers was observed on the curetted root surfaces. However, this result of healing did not consistently occur along the entire length of the curetted root portion. In the coronal part of the wound, healing was frequently characterized by connective tissue adhesion to the root surface without signs of cementum formation and fibrous attachment. The results of the experiment suggest that the periodontal ligament cells possess the ability to reestablish connective tissue attachment.

Alveolar Process↗
PubMed1982

New attachment following surgical treatment of human periodontal disease.

The present experiment was undertaken to test the hypothesis that new connective tissue attachment may form on a previously periodontitis involved root surface provided cells originating from the periodontal ligament are enabled to repopulate the root surface during healing. A mandibular incisor with advanced periodontal disease of long standing (the distance between the cemento-enamel junction and the alveolar bone crest was 9 mm) was subjected to periodontal surgery using a technique which during healing prevented the dentogingival epithelium and the gingival connective tissue from reaching contact with the curetted root surface. Preference was hereby given to the periodontal ligament cells to repopulate the previously diseased root surface. After 3 months of healing a block biopsy containing the incisor and surrounding tissue was sampled. The histological analysis revealed that new cementum with inserting principal fibers had formed on the previously diseased root surface. This new attachment extended in coronal direction to a level 5 mm coronal to the alveolar bone crest. This finding suggests that new attachment can be achieved by cells originating from the periodontal ligament and demonstrates that the concept that the periodontitis affected root surface is a major preventive factor for new attachment is invalid.

Connective Tissue↗
PubMed1982

"Critical probing depths" in periodontal therapy.

The present investigation was carried out on 15 individuals who were referred for treatment of moderately advanced periodontal disease. All patients were first subjected to a Baseline examination comprising assessment of oral hygiene and gingival conditions, probing depths and attachment levels. Following case presentation and instructions in oral hygiene measures, the patients were given periodontal treatment utilizing a split mouth design. In one side of the jaw scaling and root planing were performed in conjunction with a modified Widman flap procedure while in the contralateral jaw quadrants the treatment was restricted to scaling and root planing only. The period from initial treatment to 6 months after treatment was considered to be the healing phase and from 6-24 months after treatment the maintenance phase. During the healing phase the patients were recalled for professional tooth cleaning once every 2 weeks. During the maintenance phase the interval between the recall appointments was extended to 3 months. Reexaminations were carried out 6, 12 and 24 months after the completion of active treatment. The results revealed that treatment resulted in loss of clinical attachment in sites with initially shallow pockets, while sites with initially deep pockets gained clinical attachment. With the use of regression analysis "critical probing depths" were calculated for the two methods of treatment used. It was found that the critical probing depth value for scaling and root planing was significantly smaller than the corresponding value for scaling and root planing used in combination with modified Widman flap surgery (2.9 vs 4.2 mm). In addition, the surgical modality of therapy resulted in more attachment loss than the non-surgical approach when used in sites with initially shallow pockets. On the other hand, in sites with initial probing depths above the critical probing depth value more gain of clinical attachment occurred following Widman flap surgery than following scaling and root planing. The data obtained from the reexaminations 12 and 24 months after active treatment demonstrated that the probing depths and the attachment levels obtained following active therapy and healing were maintained more or less unchanged during a maintenance care period which involved careful prophylaxis once every 3 months. However, the data also disclosed that the level of oral hygiene maintained by the patients during healing and maintenance was more critical for the resulting probing depths and attachment levels than the mode of initial therapy used.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1981

Histometric evaluation of periodontal surgery. III. The effect of bone resection on the connective tissue attachment level.

The purpose of this study was to evaluate the effect of surgical elimination of the osseous walls of angular bony defects on the connective tissue attachment and alveolar bone levels. Using a Rhesus monkey model, 36 periodontal pockets in four animals were operated on while the contralateral pockets served as unoperated controls. Plaque control was maintained until the animals were killed 1 year after surgery. Following routine processing, the interdental tissues were analyzed histometrically. Comparing measurements of surgically treated and untreated sites, resection of the osseous walls of interdentally located angular bony defects caused not only a reduction in the height of the alveolar bone but also a significant loss of connective tissue attachment. The procedure also resulted in the elimination of angular bony defects, intrabony pockets, and in addition, reduced the height of the interdental soft tissue.

Alveolar Process↗
PubMed1980

Characteristics and development of leucine transport activity in the scutellum of germinating barley grain.

Scutella separated from grains of Himalaya barley after germination for 3 days rapidly took up l-leucine from aerated incubation media; with 1 millimolar leucine the rate varied between 4 and 14 micromoles per gram per hour and the pH optimum was at 3.5 to 5, both depending on buffer composition and prewashing time. The rate of the uptake increased with increasing concentration of leucine in a complex manner, which could be interpreted as multiphasic kinetics with apparent K(m) values of 3.4 and 15.5 millimolar below and above 3 millimolar leucine, respectively. The uptake took place against a concentration difference (highest estimated ratio 270: 1) and was strongly inhibited by dinitrophenol. Uptake was apparently due to active transport requiring metabolic energy.The development of the uptake activity during germination was studied using Pirkka barley. A low activity was present in the scutella of ungerminated grains. It began to increase after 6 hours imbibition, and the increase was biphasic, the major changes occurring during days 0 to 3 and 4 to 6. The total increase was about 20-fold.The regulation of the development was studied by allowing separated embryos to germinate on agar gel. The increase of uptake activity was strongly inhibited by inhibitors of RNA or protein synthesis. Increase did not require the presence of the embryo proper, and was not affected by gibberellic or abscisic acid. Removal of the endosperm greatly accelerated the increase of uptake activity, and the presence of 5 or 20 millimolar glutamine counteracted the removal of the endosperm. The results suggest that the availability of glutamine or amino acids in general in the endosperm may regulate the development or the activity of the transport system.

Journal Article↗