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Biomedical subjects

V Kipnis

Publications and source records attributed to V Kipnis.

26 records · Page 2Linked to original sources
PubMed1993

Interpretation of energy adjustment models for nutritional epidemiology.

The authors discuss the interpretation of three alternative energy adjustment models for nutritional epidemiology. It is shown that four different effects are addressed by these models: 1) adding nutrient N, 2) substituting nutrient N for "other" nutrients, 3) adding "other" nutrients, and 4) adding both N and "other" nutrients in a specific ratio. Each of these effects may be estimated from any of the three models. The relative standard errors for the four estimated effects are also provided.

Diet↗
PubMed1993

Effect of adhesive luting agents on the marginal seating of cast restorations.

This study determined the effect of new adhesive luting agents on the marginal seating of cast restorations. Standardized preparations were completed on freshly extracted premolars, impressions were made, and complete metal veneer crowns were cast with a base metal alloy. The castings were placed on their respective teeth and the extent of marginal opening was recorded. They were then assigned to a luting agent group: glass ionomer cement (GI), polycarboxylate cement (PC), microfilled BIS-GMA composite resin with NPG-GMA/PMDM dentinal bonding agent (GMA + NPG), microfilled BIS-GMA/phosphate ester composite resin (GMA/PE), or zinc phosphate cement (ZP). The castings were cemented and marginal openings remeasured. ANOVA revealed that the cement groups were similar before cementation (p 0.35) but were different after cementation (p < 0.0001). Tukey's multiple comparisons test identified statistically similar groups that were different from other groups and ranked them from lesser to greater marginal opening: (GI, ZP, PC) (GMA/PE, GMA + NPG).

Adhesives↗
PubMed1993

Observations of the anterior loop of the inferior alveolar canal.

The inferior alveolar nerve may extend beyond the mental foramen as an intraosseous anterior loop. The purpose of this study was to determine if panoramic radiography accurately identifies the anterior loop of the inferior alveolar canal. Adult skulls (n = 25) were radiographed using two panoramic machines both with and without radiopaque markers placed into the inferior alveolar canal and anterior loop. The anterior loop was also measured directly using flexible tubing (2 mm in diameter). Significantly fewer loops were detected in radiographs as compared with anatomic assessment (P < .001). A significant loop (> 2 mm) was identified in 92% to 96% of the direct measurements, whereas radiographs identified only 56% (Panelipse) and 76% (Orthoralix). Analysis of variance demonstrated that the skeletal length of the anterior loop was significantly greater than that measured radiographically (P < .0001). The average length of the anterior loop based on direct measurements was 6.95 mm, whereas radiographic measurements were 3.18 mm (Panelipse) and 3.45 mm (Orthoralix). The difference in detection of anterior loops among the radiographic procedures studied was not significant (P > .05).

Adult↗
PubMed1992

Effect of seating force on film thickness of new adhesive luting agents.

This study examined the effect of seating force on the film thickness of new adhesive luting agents. The method was in compliance with American National Standards/American Dental Association Specification No. 8 for zinc phosphate cement. The materials tested were zinc phosphate cement, glass ionomer cement, polycarboxylate cement, and a resinous cement with a dentinal bonding agent. All materials were manipulated exactly as described in the manufacturer's instructions, and an electronic gauge with an accuracy of 0.5 micron was used. Each class of material was measured 10 times at six different seating forces. Analysis of variance and multiple comparisons testing disclosed that the seating force and class of material strongly influenced the film thicknesses of luting agents. A mathematical model describing the response of zinc phosphate cement within the range tested was reported.

Analysis of Variance↗
PubMed1992

Comparison of whole saliva flow rates and mucin concentrations in healthy Caucasian young and aged adults.

Unstimulated and chewing-stimulated whole saliva samples were obtained from 42 healthy Caucasians; 21 were between 18 and 35 years of age, and 21 between 65 and 83 years of age. The unstimulated salivary flow rate was significantly lower in the aged group, but the stimulated flow rate was significantly higher in the aged than in the young group. Both groups showed significantly increased flow during salivary stimulation. MG1 and MG2 concentrations in unstimulated and stimulated saliva samples were significantly lower in the aged group. There were no significant correlations between salivary flow rates and MG1 and MG2 concentrations.

Adolescent↗
PubMed1991

Corrected TMJ tomography: effectiveness of alternatives to SMV tracing.

An axial (SMV) radiograph has been widely used to determine parasagittal head position in TMJ tomograms. The purpose of this study was to investigate the efficacy of alternative anatomic methods for patient positioning in TMJ tomograms. The positioning methods studied included (1) rotation of the patient's head toward the film plane on the basis of the condylar orientation as determined by an SMV radiograph, (2) arbitrary rotation of the patient's head 20 degrees toward the film plane, (3) placement of the zygomatic arch parallel to the film plane, and (4) positioning of the posterior occlusal plane parallel to the film plane. Statistical analysis of the accuracy of the positioning techniques revealed no differences in the SMV, the zygomatic arch, and the arbitrary 20 degrees positioning. Aligning the posterior occlusal plane did not adequately align the mandible into a favorable radiographic position.

Analysis of Variance↗
PubMedDate not supplied

The three-dimensional effects of adjustment and cementation on crown seating.

This study investigated the three-dimensional nature of crown fit and the effects of adjustment and luting. Standardized preparations were made on extracted premolars and impressions and dies made. Complete-coverage castings were fabricated using base metal alloy. The castings were placed on their respective teeth and measurements made. The castings were then adjusted using a silicone disclosing medium and remeasured. They were then assigned to one of five luting agent groups and cemented. A relative term describing tilting was defined. Casting adjustment decreased tilting and cementation increased tilting. Resin cements tilted castings significantly more than did zinc phosphate, glass-ionomer, or polycarboxylate cements.

Analysis of Variance↗