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Biomedical subjects

I Gillis

Publications and source records attributed to I Gillis.

4 recordsLinked to original sources
PubMed2000

A new multipurpose dental adhesive for orthodontic use: an in vitro bond-strength study.

The purpose of this study was to evaluate the compatibility of a new dental adhesive, High-Q-Bond (HQB) adhesive, for the bonding of orthodontic brackets by determining its bond strength and the mode of bond failure after debonding. Eighty extracted human premolars were divided into 4 groups, 20 in each group. In groups 1 and 2, stainless steel brackets were bonded to etched enamel with HQB and Right-On adhesives respectively. In groups 3 and 4, the same adhesives were used to bond stainless-steel brackets to roughened, old amalgam restorations prepared in the teeth. After 72 hours of incubation in saline solution at 37 degrees C, debonding was performed with a shearing force. The force at bond failure was recorded, and the mode of bond failure was examined. Results showed that when bonding to enamel, both the HQB and the Right-On material achieved adequate bond strength, and no significant difference was found between the two. However, after debonding, the HQB material left no adhesive on the enamel, whereas the Right-On material left significant amounts of adhesive on the enamel. When bonding to amalgam, the HQB material had a significantly higher shear bond strength than did the Right-On adhesive. It is suggested that HQB can be applied for orthodontic use, but further clinical studies are required to evaluate its efficacy.

Dental Amalgam↗
PubMed1999

The etiology of palatal displacement of maxillary canines.

OBJECTIVES: To test the hypothesis that palatal displacement of the maxillary canine is completely under genetic influence. DESIGN: A randomized controlled design studied cases affected by a severe expression of lateral incisor anomaly on one side and by milder expression of the same anomaly on the other. Comparison of frequency of occurrence of unilateral palatally displaced canine measured in each. Each side acted as control for the other within the same individual. SETTING AND SAMPLE POPULATION: The Departments of Orthodontics of the Universities of Jerusalem and Tel Aviv and in private practice. From approximately 12,000 consecutively treated patients, all those exhibiting an anterior maxilla with a missing lateral incisor on one side, a peg-shaped or reduced lateral incisor on the other, and a palatally displaced canine (n = 19). OUTCOME MEASURE: Missing lateral incisors, peg-shaped, and reduced lateral incisors (all genetically determined characters) have been shown to be associated with palatal displacement of the canine. The canine displacement is presumed by some authorities to be similarly genetically determined. If this is so, then the impacted canine should occur with equal frequency on either side in the patient with a missing lateral incisor on one side and a peg-shaped or reduced lateral incisor on the other. RESULTS: The canine aberration occurred far more frequently on the side of the diminutive lateral incisor. CONCLUSION: There is an environmental factor involved in the palatal displacement of maxillary canines.

Anodontia↗
PubMed1998

The effect of different porcelain conditioning techniques on shear bond strength of stainless steel brackets.

With the increasing demand for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to a porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding. In this study, 90 glazed porcelain facets were divided into three groups according to different conditioning techniques: (1) roughening with a coarse diamond; (2) hydrofluoric acid 8%; (3) microetching with 60 micron aluminum oxide particles. Each group was divided into three groups and stainless steel brackets were then bonded to the conditioned porcelain with three different dental adhesives. The adhesives used were: (1) silane+Right-On; (2) silane+Concise; (3) High-Q-Bond without silane. Four additional facets (three of which conditioned as above and one intact) were analyzed macroscopically and by scanning electron microscopy. Shear bond strength was measured with an Instron universal testing machine and a macroscopic examination of the debonded porcelain surfaces was performed. Results showed that shear bond strength was highly influenced by both conditioning technique and the adhesive. Shear bond strength of the High-Q-Bond groups was significantly lower than both the silane+Right-On and the silane+Concise groups; nevertheless the shear bond strength achieved by High-Q-Bond was enough to sustain full orthodontic treatment duration (except for the group conditioned by roughening with a coarse diamond). Scanning electronic microscopy analysis revealed that diamond roughening and microetching produced only a surface-peeling pattern, whereas hydrofluoric acid conditioning produced an extensive in-depth penetrating pattern. Hydrofluoric acid preparation produced greater shear bond strength than both diamond roughening and microetching. After debonding by means of a shearing force, the percentage of damaged porcelain surfaces in the silane+Concise groups was significantly higher than the silane+Right-On and High-Q-Bond groups.

Acid Etching, Dental↗