PubMed HealthSearch

Biomedical subjects

C G Plant

Publications and source records attributed to C G Plant.

At least 19 recordsLinked to original sources

A study of the relationship among pulpal response, microbial microleakage, and particle heterogeneity in a glass-ionomer-base material.

This investigation was designed to study the pulpal responses to glass-ionomer base materials that differ in particle size distribution. The study was carried out according to the BSI (1980) recommendations for testing restorative materials in vivo. The base materials caused more pulpal inflammation than the control material, Kalzinol, although by an indirect mechanism. A significant association was demonstrated in the statistical model between bacterial presence within the experimental cavity and pulpal inflammation. The type of restorative material has no direct association with the degree of inflammation, although the model suggests that it exerts an indirect influence via its antibacterial properties, and hence its influence on microbial microleakage. The base material, with a heterogeneous particle distribution, was associated with greater bacterial microleakage. Particle size distribution, therefore, has some effect upon bacterial microleakage, but, because of its complex effect upon several physical properties of materials, further studies are indicated.

Animals

Pulpal response to two semihydrous glass ionomer luting cements.

This study compared the pulpal responses to two innovative semihydrous glass ionomer luting cements (STA and ZIN) with those previously obtained for a conventional anhydrous glass ionomer luting cement, Aquacem. ZIN contained zinc oxide in the formulation. The study was conducted according to the BSI (1989) recommendations for testing restorative materials in vivo. ZIN was associated with minimal pulpal changes and microbial microleakage, and differed little from the control material, Kalzinol. The pulpal response to STA was similar to that observed for Aquacem, but was associated with less microbial microleakage. The statistical model demonstrated a significant association between bacterial presence within the experimental cavity and pulpal inflammation. The closer that bacteria were to the pulp, the more severe was the ensuing inflammation.

Analysis of Variance

An evaluation of a rapid setting glass ionomer cement used by general dental practitioners to restore deciduous teeth.

Twenty-one general dental practitioners evaluated the clinical handling properties and performance of a newly formulated glass ionomer cement of the powder/water type. One hundred and eighteen restorations were placed. Sixty-nine restorations were reviewed, on average, after 6 months by 17 practitioners who completed the trial. This formulation set rapidly. Approximately 90% of the restorations that were reviewed performed well over the period of assessment. The results of the trial were compared with those of trials on earlier glass ionomer cements used to restore deciduous teeth. The main advantage of the new formulation was the improvement in handling properties.

Child

In vivo morphogenetic activity of dentine matrix proteins.

Matrix proteins (EDTA-soluble and collagenase-released) from rabbit dentine have been demonstrated to show in vivo morphogenetic activity in exposed pulps of ferret canine teeth. In young adult ferrets, the reparative dentine resembled normal primary tubular dentine with odontoblast-like cells lining its formative surface. The reparative response in older animals was seen as osteo-dentine deposition. In both cases, the reparative response was characterized by its intensity within a comparatively short time period and also by the low grade or complete absence of any localized inflammatory response. Dentine matrix proteins implanted in exposed pulps of teeth provide a good experimental model for analysing the cell-matrix interactions and events taking place during odontoblast differentiation and dentinogenesis.

Aging

Preliminary studies on the in vivo morphogenetic properties of dentine matrix proteins.

Two fractions of isolated noncollagenous extracellular matrix proteins from dentine have been implanted into the base of exposed cavities in ferret canine teeth. After sealing the cavities, reparative dentinogenesis was assessed histologically after 14 and 28 days as compared to control cavities. Reparative dentinogenesis was enhanced in the presence of these matrix proteins with evidence of tubular dentine along the walls of the exposure and on the cavity floor demonstrating the in vivo morphogenetic properties of the dentine matrix proteins.

Animals

Pulpal response to an anhydrous glass ionomer luting cement.

This investigation was designed to study the pulpal responses to Aquacem, an anhydrous glass ionomer luting cement, and to compare the results with those previously obtained for a conventional glass ionomer luting cement, Chembond. The study was carried out according to the BSI (1980) recommendations for testing restorative materials in vivo. Aquacem caused more pulpal inflammation than the control material, Kalzinol, though by an indirect mechanism. The statistical model demonstrated a significant association between bacterial presence within the experimental cavity and pulpal inflammation. The type of restorative material has no direct association with the degree of inflammation, but the model suggests that it exerts an indirect influence via its antibacterial properties and hence its influence on microbial microleakage.

Animals

An evaluation of a rapid setting glass ionomer cement in general dental practice.

Forty-five general dental practitioners evaluated the clinical handling properties and performance of a newly formulated glass ionomer cement of the powder/water type. Seven hundred and ninety restorations were placed and 457 were reviewed after seven months. This formulation set rapidly. Approximately 95 per cent of the restorations performed well over the period of assessment. The results of this trial were compared with those of a trial on an earlier glass ionomer cement. The main advantage of the new formulation was the improved handling properties, notably the speed of set. Misuse of the material was the major factor responsible for poor clinical performance.

Aluminum Silicates

An evaluation of a lathe-cut high-copper amalgam alloy.

Modification of an amalgam alloy may give rise to improved physical properties. The physical properties of a newly formulated, single-composition lathe-cut amalgam alloy were studied and found to be superior to those of a conventional lathe-cut amalgam alloy. However, such modification in formulation may result in changes in the clinical handling properties of the material. The high-copper amalgam alloy was assessed by a panel of general practitioners who found that the general handling properties of the material were similar to those of conventional lathe-cut amalgam alloys. The longer term performance of the high-copper alloy was assessed by means of a blind, controlled clinical trial carried out by two operators. A 1-year assessment of the resulting restorations and tooth replicas could not distinguish between the high-copper alloy and a conventional alloy. The two alloys had both given good clinical results.

Adult

Pulpal response to an experimental adhesion promoter.

The pulpal response to an experimental adhesion promoter (PTP) used in conjunction with a composite resin material, Biogloss, is described, in lined and unlined cavities. Dycal was the lining and negative control material. Standardised Class V cavities were prepared in ferret canine teeth and the pulpal responses studied after 1, 2 and 4 weeks and 6 months post-operatively. Pre-treatment of cavities with PTP causes a reduction in pulpal inflammation at 7 and 14 days compared with Biogloss. There was no obvious difference at the longer time intervals. Pre-treatment with PTP delays the ingress of microorganisms at the cavity wall/material interface but does not prevent it in the long term in this situation. The effect of PTP is not altered if the fluid is allowed to dry naturally rather than by blow drying.

Acrylates