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Biomedical subjects

E B Hancock

Publications and source records attributed to E B Hancock.

At least 37 records · Page 2Linked to original sources
PubMed1991

A clinical evaluation of the Sulcabrush.

The purpose of this study was to compare the effectiveness of a unituft brush in combination with a conventional brush for plaque removal and maintenance of gingival health. Thirty patients presenting for routine dental care were examined and scored for plaque deposits and gingival inflammation. All subjects received a dental prophylaxis consisting of removal of all supragingival and subgingival deposits and polishing of the clinical crowns. Subjects were subsequently evaluated at 1 week, 6 weeks and 12 weeks. The addition of a unituft brush to the patient's regimen of oral hygiene procedures resulted in significant reductions at 12 weeks in both plaque scores (p less than .05) and gingival inflammation (p less than .01) when compared to the use of the conventional brush alone.

Adult↗
PubMed1986

An SEM study of overhang removal methods.

The sonic scaler, the curet, and the reciprocating motor-driven diamond tip were evaluated by comparing the number of rough root surfaces produced by each device in recontouring overhanging root-surface margins of amalgam and composite resin restorations. Ninety extracted human teeth were restored with amalgam or composite resin so that overhangs were created. Each instrument was used to remove 30 overhangs. The root surfaces apical to the overhangs were photographed under the scanning electron microscope at a magnification of x 140 and compared by five dentists, in a single-blind manner, with two control photomicrographs of surfaces classified as rough (treated with a coarse diamond bur) or not rough (treated with a greenstone). The number of rough responses for each instrument were compared statistically. For both restorative materials, the sonic scaler produced a significantly greater number of rough responses than did the other two instruments. Similar comparisons between the curets and the diamond-tip system showed no significant differences. No differences in the number of gaps produced between restoration and tooth were noted among the instruments. Clinical ease of overhang removal was greatest for the reciprocating motor-driven diamond tip and least for the curet. The approximate time to remove an overhang from a tooth was 3 minutes for the motor-driven diamond tip, 7 minutes for the sonic scaler and 15 minutes for the curet.

Composite Resins↗
PubMed1986

Prevalence and distribution of attached cementicles on human root surfaces.

A study was undertaken to determine the prevalence and distribution of attached cementicles on different root surfaces of 415 extracted human incisors, canines, premolars and molars. The teeth were boiled in water and soaked in a 5.25% solution of sodium hypochlorite to clean the root surfaces of any soft tissue and debris. Examination with a dissecting microscope showed cementicles on 144 (34%) of the teeth. Cementicles were seen on approximately 50% of the canines and molars and on fewer than 50% of the other teeth. On canines, cementicles were found most frequently in the middle and apical thirds of the roots. On molars, cementicles were found most frequently in furcations. A relationship was noted between the presence of enamel pearls in molar furcations and enamel projections from the cementoenamel junction. The findings suggest that cementicles occur in certain locations frequently enough to be of clinical importance.

Bicuspid↗
PubMed1986

Periodontics. Diagnostic, prognostic and treatment planning considerations.

The periodontal disease syndromes present the practitioner with an extensive array of clinical conditions. However, by performing a careful examination and recording of findings, the clinician will provide order to this seemingly complex picture. This careful and reasoned approach is based on a logical sequence starting with clinical observations that lead to a diagnosis of the disease entity present. This correct diagnosis in turn will lead to establishment of the prognosis and the therapeutic approach. By following these precepts, the practitioner ensures a sound biologic basis for his or her efforts. The end result is the realization of the goal of dental therapy that her is for the patient to maintain dentition in health, comfort, and function for a lifetime and minimize the potential for urgent periodontal needs.

Alveolar Process↗
PubMed1984

The healing of atraumatic and traumatic incisions in the gingivae of monkeys.

Standard wounds of simple incision and trauma were made in the gingivae of monkeys. The healing from the 1st to the 21st day was described clinically, histologically, physically and biochemically. There were no major clinical differences, but both atraumatic and traumatic wounds have reactions in the periodontium to be considered in postoperative care.

Animals↗
PubMed1982

Regeneration and repair after biologic treatment of root surfaces in monkeys. II. Proximal surfaces posterior teeth.

THE HEALING of a new attachment procedures was evaluated in monkeys. Standard flap curettage procedures were made in posterior segments having previously created periodontal pockets. The diseased root surfaces were treated with sodium deoxycholate (2%) and human plasma fraction Cohn IV1 (5%), applied to experimental sites for 1 minute each. Control surfaces were similarly treated with phosphate buffered saline. The healing at 10 weeks postoperatively was described clinically, histologically, and by histometrics. There was a significant increase in connective tissue new attachment in experimental sites, compared to controls.

Animals↗
PubMed1981

Regeneration and repair after biologic treatment of root surfaces in monkeys.

The healing of a new attachment procedure was evaluated in monkeys. Standard pedicle wounds similar to reverse bevel flaps were made in previously created periodontal pockets. The diseased root surfaces were treated with sodium deoxycholate (2%) and human plasma fraction Cohn IV (5%), applied to experimental sites for 1 minute each. Control surfaces were similarly treated with phosphate buffered physiological saline. The healing from the first to the 21st day was described (1) clinically, (2) histologically, (3) by rupture strength, and (4) by collagen production assays. All control sites healed with a dentogingival junction comprised only of junctional epithelium. Most experimental sites healed by means of junctional epithelium and some connective tissue new attachment at the apical extent of the wounds.

Animals↗
PubMed1981

The location of the periodontal probe tip in health and disease.

The periodontal probe is used clinically to measure pocket depth and the level of periodontal attachment. In order to be a more reliable, noninvasive method of assessment, it is necessary to investigate the position of the tip of the probe when at rest in the dentogingival junction. Probes were assessed for accuracy, and those closest to a standard millimeter scale were used to make pressure-cast, gold-coated, acrylic replicas. The replicas were placed in the gingival crevice of Rhesus monkeys with normal gingiva and with experimentally-induced gingivitis and periodontitis. Clinical, histologic, and histometric evaluations were made in block sections. In normal gingiva and in areas of gingivitis the probe tip stopped at the base of the crevice and was contained within epithelium. In periodontitis the probe sometimes penetrated the epithelium and stopped at the level of the connective tissue attachment. Even with gentle probing there was slight tearing and distortion of the gingiva at the base of the pocket. It was concluded that probing depth estimates indicated the level of a healthy dentogingival junction but did not differentiate between epithelial and connective tissue attachment.

Acrylic Resins↗
PubMed1981

Determination of periodontal disease activity.

The determination of disease activity has a direct impact on therapeutic measures in periodontics. Evaluations that may indicate disease activity have been reviewed under the topics of traditional evaluations, gingival crevicular fluid contents, tissue changes, circulating factors, and sulcular microbiota. The traditional methods, such as probing, radiographs, and clinical indices, were static evaluations that had limited validity in determining disease activity. When used in longitudinal tests, these methods may be used retrospectively to detect disease activity. Evaluation of the contents of gingival crevicular fluid has promise as a noninvasive method of determining tissue changes in the periodontium. To date, none of the crevicular fluid constituents has been a reliable indicator of disease activity. Tissue changes in the periodontium are important in understanding the disease processes but have had limited value as indicators of disease activity. The ability to determine disease activity through identification of substances or changes in the systemic circulation would prove quite useful to the clinician. Although some reports found lymphocyte transformation indicative of active disease, others had conflicting results. Finally, examinations of sulcular microbiota provided evidence suggesting that active periodontal disease was associated with specific groups of pathogens and with elevated counts of motile organisms. The evaluation of such pathogens and motile organisms currently shows the most promise for determining periodontal disease activity. However, long-term assessments and further clinical trials are necessary before this type of evaluation can be widely accepted. It is hoped that such studies will enable the clinician to predict the natural history of active and inactive periodontal disease.

Antibodies, Bacterial↗
PubMed1980

The use of a new topical hemostatic agent.

MICROFIBRILLARY COLLAGEN hemostat (MCH) is described in clinical use as a topical hemostatic agent for control of bleeding at the donor site of the free gingival graft procedures. On the basis of clinical trials, it is an excellent adjunct to periodontal surgical procedures.

Administration, Topical↗
PubMed1980

Biologic preparation of diseased root surfaces.

Untreated periodontally-involved teeth contain cementum-bound endotoxin, that may prevent periodontal new attachment during healing after pocket therapy. The purpose of this study was to restore biocompatibility to diseased root surfaces by a non-invasive treatment. Untreated human teeth removed for severe chronic periodontal disease were split buccolingually, the level of connective tissue was scribed on the roots, the specimens cleaned of plaque and visible calculus, and autoclaved. Cementum removal was not attempted. One member of each pair was treated with phosphate-buffered saline as a control. Sodium desoxycholate (2%), Cohn plasma fraction IV1 (5%), or deoxycholate followed by plasma fraction were applied for one minute. Roots were incubated in a suspension of gingival fibroblasts for 48 hours, then rinsed, fixed, and stained. Counts were made of the number of attached cells at 40 x magnification using an ocular grid. There was a significant increase (p less than 0.01) of the combination treatment over controls. All treatments provided a biological surface for attachment of fibroblasts, in vitro, compared to untreated roots.

Alpha-Globulins↗
PubMed1980

The healing of gingival wounds in miniature swine.

Standard wounds of simple incision and partial excision of the dentogingival junction were made in miniature swine. The healing from the 1st to the 14th day were described clinically and histologically, and the standardization of the wounds permitted quantitative and statistical analysis. In wounds that are closely adapted to the tooth, the epithelium of the new dentogingival junction contributes primarily to early wound strength recovery. This functional achievement probably would not occur with thick clots or hematomas, or with any displacement of the gingiva away from the tooth.

Animals↗
PubMed1980

Influence of interdental contacts on periodontal status.

A group of 40 healthy, young adult male naval recruits were examined and scored for gingival inflammation, plaque, food impaction, pocket depth, carious lesions, calculus, restorations and overhangs. The findings of this study support those previously reported in naval recruits, i.e. gingival inflammation is widespread involving almost every area examined. Naval recruits do not adequately remove deposits of interdental plaque, and at least one pocket with a depth of 4 mm or greater is present in three out of every four recruits. Additionally, it was found that the level of gingival inflammation was considered moderate or severe in more than 80% of the areas examined. Analysis revealed no significant relationship between contact type and Gingival Index or pocket depth. However, the significant relationship observed between food impaction and contact type, and between food impaction and pocket depth, reinforced clinical observations that food impaction contributes to periodontal pathosis. A high number of restorations had mechanical retentive areas for bacterial plaque accumulations. Thus, in addition to establishing adequate levels of interproximal surface plaque removal by the patient, the clinician should take great care in finishing the gingival margins of restorations and should eliminate those factors associated with food impaction early in treatment.

Adolescent↗
PubMed1979

The hypermineralization of diseased root surfaces.

Root surfaces which have lost their attachment due to chronic inflammatory periodontal disease present significant increases in calcium, magnesium, phosphorus, and fluoride. The clinical significance of this effect is not known in regards to wound healing, but it may be helpful in control of cervical sensitivity.

Adolescent↗