Stanley A. Alexander

Effects of orthodontic attachments on the gingival health of permanent second molars.

The aim of this study was to evaluate the effect of cemented bands and enamel bonded attachments on the gingival health of second molars. In 23 patients the right upper and lower second molars were banded, while the left upper and lower second molars were bonded. The plaque index, the gingival index, and pocket depths were greater and statistically significant on the right side, indicative of increased inflammatory activity where bands were cemented. Once the appliances were removed, both areas returned to pretreatment levels.

The glycosaminoglycans of open wounds

Abstract Histochemical methods and selective enzymatic digestions were used to study the time course and location of specific glycosaminoglycans in open rabbit wounds. Hyaluronic acid seems to be increased in whole edge tissue, which may account for wound contraction and epithelial migration. The appearance of dermatan sulfate was correlated with collagen deposition. This current work also compares the healing wound to other developmental systems in which the glycosaminoglycans have been implicated in morphogenesis and cytodifferentiation.

Effects of Self-Applied Topical Fluoride Preparations in Orthodontic Patients

The purpose of this study was to compare the effectiveness of toothbrushing followed by fluoride rinsing, fluoride gel brushing, or fluoride gel dentifrice brushing alone in controlling the demineralization that often follows orthodontic treatment. Seventy-eight consecutive adolescent patients undergoing orthodontic care were divided into 3 groups: group 1 (control) used a low-potency, high-frequency fluoride rinse; group 2 used a high-potency, high-frequency fluoride brush-on gel; and group 3 used a high-potency, high-frequency fluoride gel dentifrice. When pretreatment levels of demineralization were subtracted from posttreatment values, both gel groups displayed a significant difference (P < .05) in smooth surface demineralization sites when compared to controls. Reversal of white-spot lesions occurred in 15% of sites that exhibited pathology as a result of the fluoride and preventive regimen. These results indicate that a daily use of a 5000-ppm fluoride gel along with toothbrushing with a fluoride paste or brushing twice daily with a 5000-ppm fluoride dentifrice alone provides greater protection beyond that of tooth-brushing with a fluoride paste (1000 ppm) and rinsing with a 0.05% sodium fluoride rinse.

Bond strength of rebonded orthodontic brackets

A study was undertaken to determine the bond strength of brackets rebonded with a no-mix resin system or a paste-paste resin system. The efficacy of plastic conditioner and Enhance adhesion booster (Reliance Orthodontic Products, Inc., Itasca, Ill.) as an aid in rebonding was also evaluated. Sixty extracted human premolars were divided into two groups based on the two adhesive systems used. Both groups of 30 were subdivided and (1) initial bond, (2) rebond, and (3) rebond using plastic conditioner and adhesion booster. Samples were stressed to bond failure using an Instron machine. Bond separation occurred in the majority of samples at the enamel/resin interface. Mean bond strengths ranged from 78.8 kg cm-2 for rebonding with a no-mix adhesive and no other conditioners, to 182.7 kg cm-2 for initial bonding using a paste-paste adhesive. Rebonding using a paste-paste adhesive with no other conditioners produced a bond strength statistically indistinguishable from initial bonding with either system. Plastic conditioner and adhesion booster failed to improve rebond strength. The data suggest that, given certain circumstances, rebonding is a viable option when a bracket has been debonded.

Identification and localization of wound hyaluronidase

A method for tissue localization of hyaluronidase by a substrate film was used to study the time course and location of enzymatic activity in healing open rabbit wounds. Optically clear areas which were devoid of toluidine blue metachromasia indicated degradation of hyaluronate by hyaluronidase. Central granulation tissue exhibited hyaluronidase activity on the seventh postwound day, while whole edge tissue did not show activity until Day 18. The current work also compares the healing wound to other developmental systems in which hyaluronic acid has been implicated in morphogenesis, and where the appearance of hyaluronidase has been correlated to cytodifferentiation.

The histochemistry of glycosaminoglycans within hypertrophic scars.

Abstract Hypertrophic scars were examined by histochemical methods and selective enzymatic digestions for glycosaminoglycan localization. Film substrates of hyaluronic acid were also used to demonstrate tissue hyaluronidase activity. The scars consisted of specific areas that reacted positively to enzyme treatment and indicated that hypertrophic scars can be composed of varying levels of tissue maturity. The absence of hyaluronidase activity within the tissue signifies some abnormality or inactivity of this enzyme and may be responsible for reported increases of chondroitin-4-sulfate in hypertrophic scars.

Patterns of epidermal cell polarity in healing open wounds

Abstract The epidermal cells of the open wound margins are characteristically elongated with their long axes parallel to the wound defect. Their cytoplasmic organelles are polarized, suggesting that secretory products are released from one end of the cell. Results indicate that orientation and polarization of wound epidermis is coupled with cellular migration as wound closure proceeds.

Identification and Localization of a Mucopolysaccharidase in Human Deciduous Teeth

The presence of a mucopolysaccharidase in resorbing deciduous teeth was investigated using histochemical techniques. The loss of toluidine blue metachromasia within glycosaminoglycan film substrates indicated the presence of enzyme activity, and was related to physiologic resorption. Such activity was localized to the periodontal ligament of these teeth.

Spontaneous expulsion of a retrograde filling: Report of a case

The placement of a retrograde filling is designed to seal the apex of a tooth when conventional procedures have either failed or cannot be performed. This case report describes the mechanical failure of this procedure, as well as the expulsion of the filling material from the oral cavity.

Dental Pulp Mucopolysaccharidase: Identification and Role in Tooth Resorption

The presence of mucopolysaccharidase activity within the pulps of resorbing deciduous teeth was investigated using histochemical techniques. The loss of toluidine blue metachromasia within glycosaminoglycan film substrates indicated the presence of enzyme activity. This was related to physiologic resorption.