Search PubMed⌕ Search

Biomedical subjects

J Holz

Publications and source records attributed to J Holz.

141 records · Page 8Linked to original sources
PubMedDate not supplied

Volume of the internal gap formed under composite restorations in vitro.

OBJECTIVES: The gap that develops at the interface of dentin composite restoration during the polymerization of the resin can be subsequently filled by fluid filtrating from the pulp via the dentinal tubules. This in vitro study was designed to determine the volume of such a gap, at the occlusal floor of class I restoration and as a result of different dentin treatments and restoration procedures. METHODS: Fifty-six human third molars had their pulp chambers first sealed and connected to a hydraulic apparatus permitting microlitre fluid shift recordings. The teeth then received class I cavities of uniform dimensions and were sampled into nine groups for three dentin treatments (bonding with a dentin bonding agent, lining with a resin modified light-cured glass ionomer, lining with a zinc phosphate cement) and three restoration procedures (Bulk placement of the composite material, Multilayer, Indirect inlay). Fluid displacements were recorded during the filling procedures and stopped 30 min after the completion of the restorations. RESULTS: Dentin bonding agent treated cavities consistently presented the smallest gap volumes, followed by the GI and the ZnPO4 lined specimen. Multilayer and Indirect restoration techniques reduced the formation of gaps. CONCLUSIONS: None of the materials or techniques tested assured a gap-free interface and more effort should be directed at increasing the adhesive and sealing properties of restorative materials to be placed on the dentin.

Adhesives↗
PubMedDate not supplied

Stratification of composite restorations: systematic and durable replication of natural aesthetics.

A thorough knowledge of the internal structure of natural dentition provides invaluable information for increasing the aesthetic potential in dental restorations. To achieve the optimal aesthetic results, this knowledge must be integrated in a systematic therapeutic procedure. The learning objective of this article is to guide the practitioner in clinical case analysis, evaluation, and the application of a personalized technique of stratification for each individual case in direct composite restorations. The article evaluates treatment demarcations, differences in composite stratification between anterior and posterior teeth, color selection, and the "sandwich technique." The treatment protocol section discusses the element of reference, which can be either an adjacent natural tooth or provisional restorations, permitting the diagnostic study of a more extensive case. The structure of the element of reference is analyzed as to the enamel, dentin, and incisal edge, and replicated. Since light penetration is different in the anterior and posterior dentition, the color stratification must differ accordingly. The "worn" tooth must be distinguished from the "unworn" tooth. In color selection, the luminosity and saturation of the teeth are evaluated first; tint is selected from the element of reference.

Composite Resins↗