Biomedical subjects

C B Jenkins

Publications and source records attributed to C B Jenkins.

17 recordsLinked to original sources

PubMed1996

Second-trimester amniotic fluid or maternal serum interleukin-10 levels and small for gestational age neonates.

OBJECTIVE: To evaluate if interleukin-10 levels in either early second-trimester amniotic fluid (AF) or maternal serum can be utilized as a predictor of the subsequent occurrence of small for gestational age (SGA) infants after controlling for gestational age at delivery. METHODS: We identified patients who underwent genetic amniocentesis for standard genetic indications or maternal blood sampling for maternal serum alpha-fetoprotein (MSAFP)/triple screen between January 1992 and February 1995 with available follow-up delivery data. Small for gestational age was defined as birth weight less than the tenth percentile for gestational age. Control patients were matched for gestational age at delivery, maternal age, race, and parity with at least two controls for each study patient. We excluded patients with maternal immune disease, chronic hypertension, diabetes, asthma, congenital heart disease, multiple gestation, and fetuses with structural or chromosomal anomalies. Second-trimester AF and serum samples were assayed for interleukin-10. Potential confounding variables considered were MSAFP level, smoking history, pregnancy-induced hypertension, and neonatal gender. The interleukin-10 levels were normalized using natural log transformation for statistical analysis. Statistical analysis included chi 2, Fisher exact test, and analysis of variance, with P < .05 considered significant. RESULTS. From the AF data base, 18 patients (6%) delivered SGA neonates and were matched with 46 controls. From the maternal serum data base, 13 patients (7%) delivered SGA neonates and were matched with 45 controls. Neither AF nor maternal serum interleukin-10 levels were significantly different in patients subsequently delivering SGA neonates compared with controls (AF: median 21.0 pg/mL. [range 13.8-27.6] versus 17.5 pg/mL. [range 8.9-362.12], P = .18; serum: median 15.7 pg/mL [range 9.9-73.5] versus 18.7 pg/mL [range 9.7-71.7], P = .60, respectively). No significant differences were identified in gestational age at sampling, maternal smoking history, pregnancy-induced hypertension, or elevated MSAFP in patients delivering SGA neonates compared with controls (P > .05 for each). As expected, birth weight was significantly lower in patients delivering SGA neonates compared with controls (P < .001). CONCLUSION: Second-trimester AF or maternal serum interleukin-10 levels are not predictive of subsequent delivery of SGA infants.

Adult↗

PubMed1993

Multiple external root resorption. Case report.

A case of a patient with multiple external root resorption affecting principally the molars and premolars is described. This case is unusual in that although both right and left molar and premolar teeth are involved, the resorption is worse on the left side and affects only the distal roots of the molars.

Adult↗

PubMed1991

The bonding of an adhesive resin cement to single and combined adherends encountered in resin-bonded bridge work: an in vitro study.

Although resin-bonded bridges should ideally be bonded to enamel, abutment teeth may present with dentine or restorations at the bonding sites. This study assessed the influence of bonding to such adherends on bridge retention by using tensile bond strength measurements as the criteria for judgement. An adhesive resin cement (Panavia Ex) was bonded to single adherends of enamel, dentine, composite resin, glass ionomer or amalgam, and to combined adherends of enamel/dentine or enamel/restorative material. The bond strength to enamel (28 MPa) was comparable with that to composite resin (25 MPa), but significantly higher than to dentine (8 MPa), amalgam (8 MPa) and glass ionomer (13 MPa). When the bonding area was half enamel and half restorative material, the bond strength was only equivalent to that obtained when the entire bonding area consisted of restorative material, the less favourable adherend. A similar trend was observed with specimens of enamel/dentine. This indicated that the magnitude of the bond between the resin cement and combined adherends was limited by the strength of the bond to the less favourable adherend. It appears that extending a bridge retainer to cover exposed dentine, a glass-ionomer filling or an amalgam filling, could adversely affect the bridge retention.

Acrylic Resins↗

PubMed1990

Changing perceptions of the requirements of cavity preparations.

Perceptions of the requirements of cavity preparations have changed over the years. These have had a significant effect on undergraduate teaching at the University of Bristol Dental School, an explanation of which may help general dental practitioners in their quest for information on this important aspect of dental practice. A method is described for teaching undergraduate dental students cavity preparation in caries-free teeth, based upon the position, shape and extent of imaginary carious lesions. Scale diagrams of teeth are used, on which imaginary caries at the amelodentinal junction has been marked. The students are instructed to apply the principles of cavity preparation to equivalent, but caries-free, teeth in the laboratory. 'Outline forms' and other predetermined cavity shapes are not taught. Dental practitioners may find it appropriate to apply similar thinking to cavities they prepare in everyday practice, in an endeavour to avoid the unnecessary removal of tooth tissue that would be better retained.

Audiovisual Aids↗

PubMed1989

The bonding of glass-ionomer cements to dental amalgam.

Clinicians are frequently confronted with the problem of ditched amalgam restorations. Materials which develop strong bonds to amalgam and tooth substance appear to be suitable for repair of such restorations and eliminate the need for complete replacement. This study evaluated the bond strengths of three glass-ionomer cements to amalgam made from conventional and high copper alloys. It was found that the bond strength values to amalgam were comparable with those to enamel and significantly higher than those to dentine. All bonds to the high copper amalgam failed in a cohesive mode; for the conventional amalgam, failure was either of the adhesive or cohesive type.

Copper↗

PubMed1989

Tensile strength of enamel-resin-metal joints.

This study evaluated the tensile strength of enamel-resin-metal joints formed with four adhesive systems for attaching resin-bonded FPDs. Groups of 10 cast alloy cylinders were blasted with 50 microns alumina, washed, and prepared for bonding according to the resin as follows: (1) Panavia Ex with no treatment, (2) Super-Bond oxidized for 2 minutes with potassium permanganate in sulphuric acid, (3) Conclude electrolytically etched, and (4) ABC conditioned with primer. The cylinders were bonded to etched human enamel and after 24 hours in water at 37 degrees C the tensile strengths of the joints were recorded. Joint failure was examined under a stereomicoscope and a scanning electron microscope. The results demonstrated that the adhesive system influenced the tensile strength and mode of failure of the joints.

Chromium Alloys↗

PubMed1987