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F H Hendriks

Publications and source records attributed to F H Hendriks.

8 recordsLinked to original sources
PubMed1986

Composite versus amalgam restorations. A three-year clinical evaluation.

In a clinical study the behaviour of posterior composite restorations was evaluated. For the study, 232 Class I or II restorations in premolars and molars were made by three operators in a group of forty-nine adult patients. Each patient underwent one or two series of four restorations. The materials within a series were a strontium glass filled composite (Profile), a microfilled composite (Estic MF), a macrofilled composite (Adaptic Radiopaque) and a high copper amalgam (Dispersalloy). The last two materials served as a negative and positive controls respectively. For a period of 3 years the clinical behaviour was evaluated yearly with the USPHS criteria (anatomic form, marginal adaptation, colour match, marginal staining and caries). Differences in the ratings of the criteria between materials, tooth type and evaluation year were tested statistically for significance. The number of restorations replaced after 3 years in clinical service was eight (= 3.6%). The results showed that the material, tooth type and evaluation year all have an influence on the anatomic form and the colour match of the restoration. The behaviour of the three composites with respect to colour match, marginal adaptation and marginal staining was acceptable. For anatomic form, however, only the behaviour of the microfilled composite Estic MF was still acceptable after 3 years.

Adult↗
PubMed1985

A method to determine the loss of substance of dental restorations.

A method is described for quantitative in vivo wear measurements on Class I and II composite restorations. Class I gold inlays were made in an acrylic premolar and molar. Over the occlusal parts of the teeth cast silver caps were made after releasing the surface of the inlay with tinfoil. Wear on the restorations was simulated by grinding away some gold from the inlay. Silicon impressions of the teeth were made with the caps both before and after this simulation. The volume and the average thickness of the removed gold was measured from the weight of the enclosed impression material in the cap before and after the wear simulations, the density of the tinfoil and the impression material as well as thickness and the weight of the tinfoil-release. Values expected for the volume and the average thickness of the removed gold were calculated from the weight of the restored acrylic teeth before and after the wear simulation, the weight, the density and the thickness of the tinfoil and the density of the gold used for the inlays. Measured and expected values are linearly correlated (r = 0.97). An average wear thickness of the occlusal surface of a particular tooth of at least 30 micron can be detected. Because of its simplicity, inexpensiveness and accuracy the wear measurement method is highly productive and suitable for large scale and long-term clinical research on the wear behaviour of posterior composites.

Acrylic Resins↗
PubMed1985

Cost benefit analysis of direct posterior restorations.

A clinical study was conducted in which three operators made 232 Class I and Class II composite and amalgam restorations in a group of 49 adult patients. The time for different parts of the operative process was measured. The time periods were analysed as to the influence of the factors operator, tooth type and number of surfaces, by an analysis of variance (ANOVA). Results show that the various factors have a significant influence on the total treatment time. The treatment time for amalgam restorations is equal to the treatment time of composite restorations. The productivity of making restorations from the 'best' available amalgams, i.e. the amalgam with an extrapolated half-life time of more than 20 yr, turns out to be more than 3-4 times better than that of the 'worst' amalgams (half-life time 4 1/2-8 yr) and more than two times better than that of making restorations of the best composite material, used in this study (extrapolated half-life time of Estic MF is 10 yr).

Adult↗