PubMed Health⌕ Search

Biomedical subjects

H Tal

Publications and source records attributed to H Tal.

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

Cryosurgical depigmentation of the gingiva. A case report.

Gingival melanin pigmentation (GMP) occurs in all races of man. Although clinical melanin pigmentation does not present a medical problem, demand for cosmetic therapy is commonly made by fair-skinned people with moderate GMP. The present study was undertaken to test the effectiveness of cryosurgical destruction of the gingival epithelium in the removal of gingival melanin pigmentation. The patient was a fair-skinned Ashkenazi Jew with moderate GMP who demanded any possible "cosmetic therapy" which would convert her "black gums" to "normal". Gingival cryosurgery was carried out by segments. A gas expansion cryoprobe cooled to -81 degrees C was applied to the gingiva for 10 s. Frozen sites thawed spontaneously within 1 min. Superficial necrosis became apparent within a week. Treated sites were covered by epithelium within 2 weeks following freezing and keratinization was completed after 3-4 weeks. The treated gingiva appeared normal and remained depigmented until the present time, 20 months following freezing. It is concluded that cryosurgery may prove to be the treatment of choice when gingival depigmentation is indicated.

Adult↗
PubMed1986

Periodontal attachment responses to surgical injury in the cat. Removal of buccal bone with and without placement of foreign body at ligament periphery.

Recently, PDL progenitor cells were claimed essential for the establishment of new connective tissue attachment to root surface. To further test new periodontal attachment after surgical injury, portions of the buccal alveolar plate were removed from the canines of 4 cats. Removal of bone was carried out with or without removal of the underlying PDL, and in half of the experimental sites, dental amalgam was placed at ligament periphery. Tissue blocks were prepared for routine histologic evaluation (H & E) and specific collagen stains (Mallory Trichrome and Mallory PATH). Exfoliation of amalgam was noted in 6 experimental sites during the healing period. At all sites, plaque accumulation and marginal gingivitis were observed before sacrifice. Histologic observation demonstrated limited new connective tissue attachment to root surfaces at PDL periphery where bone, PDL and cementum had been removed. Where PDL was retained, connective tissue attachment was present which appeared to be the result of fiber interdigitation between root-inserted fiber ends and gingival wound edge fibers. "Blockage" of PDL cell migration by amalgam could not be well controlled. However, the placement of amalgam seems to have interfered with new connective tissue attachment and/or cementogenesis. In 5 specimens, root resorption had progressed into dentin. At these sites, collagen tufts appeared to arise from dentin. These tufts were in intimate contact with zones of dense inflammatory cellular infiltrate and connective tissue elements. We suggest that this observation may be a further tissue response to injury, namely: root resorption with the unmasking of dentinal collagen, which may finally lead to fiber interdigitation.

Alveolar Process↗
PubMed1986

Tooth loss and retention: analysis on 500 maxillae of a multitribal group of Bantu-speaking South African blacks.

This study analyzes tooth loss and retention in 500 dry maxillae of adult South African Bantu-speaking blacks. The tribe, sex, and stated age at death were available. Specimens were equally distributed over the third to the seventh decades of life. The presence of dental units was recorded and analyzed between and within age groups. A total of 5063 dental units was recorded. Reduction of the frequency of dental units was mild and not significant between the third and fourth decades of life and between the sixth and seventh. Severe and significant tooth loss was recorded between the fourth and the fifth, and between the fifth and the sixth decades of life. Specimens from younger individuals (from 21 to 30 years of age) retained more teeth in the anterior region; after the third decade of life, there was a clear and significant persistence of canines with tendency toward loss of teeth anterior and posterior to them. Based upon the present observations and previous studies in this population, it is suggested that: (a) in most teeth, tooth retention pattern is indirectly related to periodontal bone loss (In the canines, however, the long roots rather than "resistance" to periodontitis may be the cause for the relatively high longevity rate); and (b) caries may have been the main cause for tooth loss until the fourth decade of life--later, periodontal disease may have become the predominant reason.

Adult↗
PubMed1986

Repigmentation of the gingiva following surgical injury.

Oral melanin pigmentation is not uncommon in some races and ethnic groups. Repigmentation of depigmented oral mucosa has been described after chemical, thermal, surgical, pharmacologic or idiopathic factors. Information on the repigmentation of oral tissues after surgical procedures is extremely limited. The communication reports on gingival repigmentation over a 7 to 8 year period following removal of gingival tissues. Pigmented keratinized gingiva was removed in two Jewish Yemanite adult males, who had moderate or heavily pigmented gingiva. After surgery, the exposed lamina propria was covered by periodontal pack for 7 to 10 days. The tissues were then observed periodically for signs of repigmentation. Healing was uneventful and the surgically treated areas in both patients remained depigmented over the first 2 years. After 32 months, some pigmentation was found in one of the patients, and with the exception of two limited sites, the area was completely repigmented after 7 years. The surgically treated area in the second patient remained depigmented over an 8-year follow-up period. These observations agree with previous reports that describe gingival pigmentation as spontaneous and suggest that further controlled experimental studies be undertaken to explore the biologic basis for repigmentation.

Adult↗
PubMed1986

Healing following devitalization of sites within the periodontal ligament by ultralow temperatures.

Healing of specific rat periodontal ligament (PDL) sites following freezing injury was monitored histologically to evaluate repair potentials of this tissue. Buccal alveolar plates supporting the first mandibular molar in 15 adult rats were surgically exposed. The coronal 3 mm of plate covering the buccal surface of the mesiobuccal root and underlying periodontal ligament and cementum were subjected to ultralow temperature using a gas expansion micro/cryoprobe, diameter 2 mm, cooled to -81 degrees C for 5 seconds. Tissues were repositioned and sutured in layers. Animals were sacrificed at 1, 24 and 72 hours and at 2, 5 and 7 weeks following surgery and mandibles removed for histologic analysis. Microscopic evaluation of 24-hour specimens showed loss of cellular vitality in the PDL, adjacent bone and cementum at experimental sites. Cellularity of the gingiva coronal to the crest, and of the PDL apical to the experimental zone, appeared to be within normal limits. Transition between experimental and nonexperimental sites was abrupt. After 72 hours cells from the PDL and gingiva appeared to migrate into and repopulate the noncellular PDL. Few capillaries surrounded by mesenchymal cells and limited polymorphonuclear neutrophil infiltration were observed within the injured PDL site. Marginal gingival inflammation was minimal. At 14 days, collagen lysis, resorption of alveolar bone and root resorption were evident. In the PDL space, nonfunctionally oriented, cellular connective tissue elements were abundant. At 5 and 7 weeks, root resorption was marked. At this time interval, osteogenesis at seams of nonvital bone, repair cementum at sites of root resorption, and at times, ankylosis, were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Process↗
PubMed1985

Periodontal bone loss in dry mandibles of South African blacks: a biometric study.

Periodontal bone loss associated with periodontitis results in increase in the distance between the cemento-enamel junction (CEJ) and the alveolar bone crest (ABC). This study analyzed periodontal bone loss in 100 mandibles of South African blacks who were never exposed to preventive or restorative dental treatment. Specimens were equally distributed over the third to the seventh decade of adult life. CEJ-to-ABC (CA) distances were measured along 4904 surfaces of 1076 teeth. Analysis of the measurements showed that, generally, CA distances increased with age; differences were substantial between the first and fifth age groups. The incisors were most severely affected in all age groups, and bone loss was less severe around posterior teeth. Pre-molars and second molars lost the least bone. No significant differences between measurements on the buccal, lingual, mesial, or distal surfaces for these teeth were found. Measurements on the right and left sides of the mandible did not differ significantly. These observations may, in part, have been influenced by mid-life loss of teeth caused by severe periodontitis; their absence from the sample may have masked the true extent of periodontal bone loss. The difference in age of eruption and, therefore, the difference in period of exposure to the oral environment may account for the more severe bone loss in the anterior teeth, especially in specimens from younger individuals (21-30 years).

Adult↗
PubMed1985

Elimination of epithelium from healing postsurgical periodontal wounds by ultra-low temperature. Initial observations.

Prevention of epithelial migration into healing postsurgical periodontal wounds may enhance connective tissue attachment. This study attempted to destroy selectively epithelium on gingival flap surfaces by ultra-low temperature. Sixteen sites in four young adult cats received subcrestal reverse bevel incisions followed by sulcular incisions. Full thickness periodontal flaps were reflected, the remaining supracrestal soft tissue surrounding the teeth was removed, and exposed root surfaces were curetted. Narrow zones measuring about 4 mm along the coronal margins of the flaps were exposed to ultra-low temperature for 5 seconds using a gas expansion cryoprobe cooled to -81 degrees C and placed at the oral gingival aspects of the flaps. Flaps were then repositioned and sutured. Control sites were sham-operated with the cryoprobe kept at room temperature (25 degrees C). Gingival biopsies were taken at 1 hour and at 2, 4, 8 and 12 days following surgery. Microscopically, 1-hour postfreezing and control specimens appeared similar. At 2 and 4 days, large surface areas of corium were denuded of epithelium or were covered by necrotic debris. Mild inflammatory responses were noted within the corium. At 8 days, the epithelium almost completely covered the corium with some initial formation of crevicular epithelium. After 12 days, crevicular epithelium was observed in all tissue sections. No significant morphologic damage to the connective tissue was noted at any time. We, therefore, concluded that low cryodoses can effectively destroy oral gingival epithelium without causing significant morphologic damage to the underlying lamina propria at this level of observation.

Animals↗
PubMed1985

Scanning electron microscope evaluation of wear of dental curettes during standardized root planing.

Root planing relies upon the quality of instrument cutting edges. This study evaluated the sharpness and wear of some dental curettes available in the market following standardized root planing procedures. Nine working edges of nine Gracey No. 1/2 DE curettes, three each from three different manufacturers, were used as controls. These unused factory-sharpened edges were examined by scanning electron microscope (SEM). Eighteen edges of nine curettes of the same brands were likewise examined after root planing procedures. Root planing was carried out on extracted one-rooted teeth mounted in natural positions in manikin jaws. Working areas measuring 3 X 5 mm were marked on root surfaces previously exposed by periodontitis. Root planing procedures included 15 vertical strokes done by either Side 1 or Side 2 of each instrument in relation to a single working area of a tooth, and the same procedure repeated 3 times using the opposite side of the curette. All working edges were examined at points 1 and 2 mm from the tip under 500 times magnification. Edge deformation increased significantly from the control group to the "15-stroke" group and from the "15-stroke" group to the "45-stroke" group. Factory-sharpened curettes (control) were sharp, with functional wire edges present on 55% of the specimens. After 15 strokes, nonfunctional wire edges and narrow edge deformations with bevels measuring less than 15 mu were present. After 45 strokes eight cutting edges (88.9%) showed bevels wider than 15 mu. The difference between the three brands was not significant in any group (i.e., controls, 15 strokes, 45 strokes). Further study is indicated to evaluate the relationships between bevel dimensions and root planing effectiveness.

Curettage↗