Biomedical subjects
Publications and source records attributed to T P Croll.
Ingenuity in research and development of glass ionomer systems has slowly but surely improved their handling properties and appearance. The author reviews the latest developments in relation to esthetic dentistry.
This study evaluated the relationship of polymerization shrinkage during composite resin veneer placement to direction of the polymerization light source. Fifty maxillary permanent incisors were obtained and divided into five groups of ten. Groups I and II had preparations placed in enamel. Groups III, IV, and V had preparations placed in dentin. In groups I and III, an unfilled bonding resin was placed and polymerized from the facial aspect, followed by placement and polymerization of a hybrid composite resin. Groups II and IV were initially polymerized from the lingual direction. In group V, the unfilled resin and hybrid composite resin were polymerized simultaneously from the facial aspect. Statistical analysis indicated that there was significantly less axial microgap formation during lingual polymerization when the preparation remained in dentin, but demonstrated that there was no statistically significant difference when the preparation remained in enamel.
Bonded glass-ionomer-silver-cement cement and visible light-hardened glass-ionomer liner and base material have proven to be reliable dentinal and enamel restoratives since the mid-1980s. When used within their limitations, they offer advantages over mechanically interlocked silver amalgam material. A light-hardened glass-ionomer-resin cement restorative material, which appears to have greater wear resistance and fracture toughness than prior glass-ionomer cements, has been introduced. This paper describes use of the new material and discusses its potential future implications.
Glass-ionomer-silver-cermet cement has proved to be a worthy alternative to silver amalgam for restoring certain Class I lesions in primary teeth. Such restorations are now known to last up to 8 years without need for repair or replacement. Cermet cement has also been used for interim restoration of permanent teeth in special cases, with ideal results. The procedure for placing a glass-ionomer-silver-cermet cement Class I restoration is described.
Severely fractured anterior teeth often require immediate repair, while long-term restoration is delayed until a healing period is completed. This paper details a technique of immediate emergency repair of a fractured mandibular incisor followed by placement of a bonded composite resin complete-coronal restoration months later. Careful diagnosis, gentle handling of the freshly traumatized tooth and surrounding tissues, and ideal selection and use of the respective bonding materials are necessary to ensure eventual replication of form, function, and tooth shade when the long-term restoration is placed.
Improvements in dental materials and methods of their use necessitate continuing modifications of clinical techniques. This paper details a step-by-step procedure for restoring a Class V carious lesion with polishable, visible light-polymerizing composite resin combined with one of the new-generation dentin-enamel bonding systems.
Certain enamel coloration defects can best be eliminated by a combination of treatment methods. This report describes the treatment of two patients whose enamel discoloration was corrected with a combination of enamel microabrasion and patient-administered dental bleaching with a carbamide peroxide gel solution.
The most durable and reliable method of retaining a primary molar in the mouth after a pulpotomy procedure is complete-coverage restoration with a preformed stainless steel crown. This paper describes a method for performing pulpotomy and stainless steel crown restoration of a primary molar. Neither formocresol, glutaraldehyde, nor calcium hydroxide is used during the pulpotomy phase of the treatment.
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Enamel surfaces have been found to acquire a glasslike luster and an exceptionally smooth texture following enamel microabrasion procedures. A commercially available enamel microabrasion compound containing abrasive particles and a mild concentration of hydrochloric acid, when applied by rotary compression, simultaneously abrades and erodes (abrosion) the enamel surface. Human enamel surfaces were evaluated microscopically after routine enamel microabrasion procedures. The results show distinct evidence of enamel surface changes that have been described as the abrosion effect.
Two cases in which tooth splinting was required after traumatic dental injuries are documented. In each patient, an acid-etch-retained composite resin/ligature wire splint was used to stabilize displaced teeth after they were replaced into their proper positions. The step-by-step splinting technique is described, and the rationale for the method is reviewed.
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A visible light-hardening, glass-ionomer cement, dentinal base/liner has been used as a dentinal and enamel replacement restorative material for certain lesions in primary teeth. The material has all the advantages of glass-ionomer cements and the additional advantage of rapid hardening by light curing. The procedure for using the material as a restorative material in primary teeth is described, and several cases are documented.
When practitioners fully understand the nature of the glass ionomer materials and use them within their limitations, their use can improve the quality of restorative dental care for young patients. The materials for young patients can be classified as luting cements, dentin replacement liners and bases, and glass ionomer dentin and enamel restorative material. Future research efforts should be directed toward improving the glass ionomer cement by increasing fracture toughness and wear resistance, decreasing hardening time, and simplifying the sensitive handling technique.
Enamel surface "dysmineralization" can be defined as a disturbance in formation of the inorganic component of enamel during amelogenesis. Enamel microabrasion, a method of removing certain enamel dysmineralization and decalcification coloration defects, is described. In many cases, with insignificant and unrecognizable loss of enamel, superficial enamel discoloration defects can be permanently eliminated, improving the appearance of treated teeth.
Proper use of modern composite resin materials precludes the need to mask Class III restorations behind residual labial enamel. With the use of micromechanical enamel bonding, chemical adhesion to dentin, and traditional mechanical interlocking, visible Class III composite resin restorations that exactly simulate the color and texture of natural enamel surfaces can be placed. Such imperceptible restorations, when performed properly, can last for many years. This paper details a step-by-step procedure for restoring a Class III carious lesion with composite resin, using labial access and a recently introduced dentinal and enamel bonding agent.