The influence of varying layer thicknesses on the color predictability of two different composite layering concepts.

OBJECTIVE: Optical properties of teeth are mimicked by composite layering techniques by combining a relatively opaque layer (dentin) with more translucent layers (enamel). However, the replacing material cannot always optically imitate the tooth when applied in the same thickness as that of the natural tissues. The natural layering composite system is available in 2 concepts: (1) dentin (D) and enamel (E) have the same shade but with different translucencies; (2) D and E have different shades where E is always the same high translucent shade. The objective was to evaluate the influence of varying thicknesses of E and D composites on the overall color and on the translucency for both concepts. METHODS: For each concept three composite brands were tested; Concept 1: Clearfil Photo Bright (Kuraray), Herculite XRV Ultra (Kerr), Venus Diamond (Heraeus Kulzer); Concept 2: Amaris (VOCO), CeramX Duo (DENTSPLY) and Point4 (Kerr). Two specimens of each shade (A1-A3) per composite were made of standardized thicknesses with a poly-acrylic mold and Teflon cover, making 36 specimens of wedge-like dimension. The L*a*b* values were measured three times against a white and black background (n=216). Student's t-tests revealed significant levels between the average ΔE* values of the 3 areas for each composite. RESULTS: Statistically significant differences (p<0.05) were found for all thicknesses and for all shades between the concepts. Concept 2 showed greater variations in ΔE* with increased thicknesses. SIGNIFICANCE: Concept 2 composites are more sensitive to layer thickness changes, which implicates less predictability in a daily clinical routine.

Can a single composite resin serve all purposes?

The consensus view less than a decade ago was that direct posterior composites should be restricted to small restorations, preferably in premolar teeth with little, if any, occlusal function. Major advances in adhesive systems, materials and restorative techniques have combined to allow us to question this view and our increased clinical evidence base makes it appropriate to reconsider this viewpoint.

Extended indications for directly bonded composite restorations: a clinician's view.

Adhesive techniques play an important role in almost every discipline of dentistry. Compared to conventional direct and indirect techniques, the direct adhesively bonded composite restoration offers many advantages. This article summarizes and illustrates some of them.

A simple method to protect patient and environment when using sandblasting for intraoral repair.

Repair or correction of intraoral restorations can be an alternative to complete replacement. A simple sandblasting device is very effective in producing a microretentive surface on every restorative material. A disadvantage of the technique is the production of an aerosol contaminated with the small, abrasive aluminum-oxide particles. In this article, a simple solution is given to protect the patient and environment against this dust during intraoral reparatory procedures involving sandblasting.

[Adhesive techniques in the treatment of tooth wear due to bruxism]. / Adhesieve technieken bij de behandeling van tandslijtage door bruxisme.

Wear due to bruxism is not restricted to those surfaces of the tooth that are loaded by occlusion and articulation. Due to tooth flexure wedge-shaped lesions, so-called abfractions, may develop. In the treatment of wear caused by bruxism, direct composite restorations may play an important role. Composite resin can be used to cover exposed dentin and to restore the incisor and canine guidance. In combination with a nightguard, such a treatment may prevent further wear.

Clinical evaluation of Dyract in primary molars: 3-year results.

PURPOSE: To evaluate the 3-year clinical performance of Dyract in primary molars. MATERIALS AND METHODS: In 55 children (aged 4-9 years) 91 restorations were placed and 76 were available for evaluation after 2 years. After 3 years, 40 teeth were exfoliated leaving 37 restorations for evaluation. RESULTS: During the entire study, four restorations failed and had to be replaced. One restoration fractured after 6 months and another after 1 year. Two other restorations were completely lost between the second and third year's evaluation. Furthermore, three restorations showed minimal recurrent caries, which did not need additional treatment. Wear of the restorations was considerable. However, this was also true for the point of reference for the wear measurement on the primary molars. The excellent handling characteristics and the low failure rate during the 3-year study suggest that this compomer is a reliable restorative material in primary molars.

Necessity of bevels for box only Class II composite restorations.

STATEMENT OF PROBLEM: The tooth preparation of a bevel is recommended to improve marginal quality of a composite restoration. However, in small Class II restorations, it is unclear if a bevel also contributed to a better marginal fit. PURPOSE: This study investigated the influence of tooth preparation design on microleakage of minimal posterior Class II composite restorations. MATERIAL AND METHODS: Box-shaped Class II tooth preparations for posterior composite restorations in maxillary premolars were restored with a total etch technique. The tooth preparations were beveled or non-beveled and the box prepared at a right angle cervically or additionally excavated. The facial and lingual box margins were also either beveled or unbeveled. The teeth were thermocycled and immersed in a dye solution. After sectioning specimens, dye penetration at the facial and palatal margins was recorded. RESULTS: A bevel-reduced microleakage both at the cervical and ascending walls. Enamel cracks were observed along certain unbeveled margins as recorded in this study. The additional excavation did not contribute to reduction of microleakage. CONCLUSIONS: Tooth preparation of a bevel is recommended for an optimal marginal seal in small box-type Class II composite restorations.

Evaluation of the clinical performance and effectiveness of adhesively-bonded metal crowns on damaged canine teeth of working dogs over a two- to 52-month period.

In this clinical study, 41 metal full crown restorations of canine teeth were placed in 18 working dogs. Twenty-six canine teeth had severe attrition with no involvement of the pulp cavities; 15 fractured canine teeth were endodontically treated. With the exception of one tooth, at least one-third of the coronal part of each canine tooth was available for a supragingivally performed, minimal tooth crown preparation. A dental resin luting cement technique was used to bond the electrolytically etched crown (made from an alloy of cobalt-chrome-molybdenum) to the tooth. The metal crowns were slightly shorter and with a more rounded tip than the original tooth. Posts or post-and-core techniques were not used. Median follow-up period was 30 months (range 2 to 61 months), at which time 36 crowns were found to be intact and functional. Five crowns were lost; three as a result of subsequent injury and fracture of the tooth below the crown; one as a result of use of less than one-third of the coronal portion of the tooth for retention of the crown; and one as a result of an oblique fracture of the root.

Microleakage of Class II box-type composite restorations.

PURPOSE: To investigate whether in small box-type Class II preparations the use of glass ionomer cement, a dentin primer or a different type of conditioner had an effect on the microleakage compared to a more simple total-etch system using a phosphonated bonding agent. MATERIALS AND METHODS: In extracted premolars, 84 box-type Class II composite resin restorations with margins in enamel were made following a standardized protocol. A transparent matrix system was used and the composite resin was applied in two layers. The teeth were restored using a phosphonated total-etch bonding system as a control (Photo Bond). In the experimental groups a glass ionomer lining-cement (Vitrebond), a total-etch adhesive including a primer (Scotchbond Multi-Purpose) and a total-etch adhesive using a self-etching primer (Liner Bond 2) were used. The teeth were thermocycled, immersed in a dye solution and sectioned. The cervical and occlusal dye penetration was assessed. RESULTS: Preventing microleakage was not more effective in the experimental groups than in the control group (P < 0.05). Scotchbond MP groups using maleic acid showed statistically significant more microleakage than the control group (Photo Bond) at the cervical side. Liner Bond 2 and Scotchbond MP groups using maleic acid showed statistically significant more microleakage than the control group at the occlusal side. The use of a lining cement did not improve the quality of the restoration. From this study it was concluded that in this type of restoration, total-etch systems using a primer are not always an improvement.

Class I occlusal composite resin restorations: in vivo post-operative sensitivity, wall adaptation, and microleakage.

PURPOSE: To investigate the effect of restoration technique and adhesive system on the post-operative sensitivity and marginal adaptation of Class I occlusal composite resin restorations placed in vivo. MATERIALS AND METHODS: 48 Class I cavities were restored in vivo according to one of three protocols: (1) Scotchbond Multi-Purpose/P50 placed in increments; (2) Scotchbond Multi-Purpose/P50 placed in bulk, and (3) Clearfil Liner Bond 2/Clearfil Ray Posterior placed in bulk. Post-operative sensitivity and sensitivity on loading were recorded 5-7 weeks after placement of the restorations; the teeth were cautiously extracted, immersed in a dye solution and sectioned. SEM observations were made from epoxy resin replicas. Microleakage and gap formation was assessed. RESULTS: No differences among adhesive systems or restoration procedures were found for microleakage. Post-operative sensitivity was reported in 14% of all teeth but was absent in the Clearfil Liner Bond 2 group. Sensitivity on loading was experienced by patients in 56% of the restorations. Group 1: nine teeth; Group 2: 15 teeth; Group 3: three teeth. Differences were statistically significant for all three groups. The SEM analysis showed that restorations placed in two layers showed less gaps than restorations placed in bulk.

Restorative dental treatments of abraded canine teeth in a Sumatran tiger (Panthera tigris sumatrae).

A Sumatran tiger had developed severely abraded canine teeth by biting on cage-bars. This resulted in weakening and marked sensitivity of the teeth. Indications for, techniques of and complications of restorative dental treatments are described. The outcome of different restorative dental treatments indicates that endodontic treatment should be carried out first if the fracture of a weakened tooth is anticipated. To improve retention, the acid-etch technique is preferred in combination with macroretentive preparations. In this case, amalgam was used successfully in combination with composite resin to restore function to a canine tooth with a large distal defect.

Consistency of resin composites for posterior use.

OBJECTIVES: The aim of this study was to compare a large set of resin composites suitable for application in stress-bearing areas on the basis of their consistency. METHODS: A variety of posterior resin composites were tested using an apparatus that was originally designed for determination of the consistency of elastomeric impression materials (ISO 4823, 1992). The consistency of a standardized volume of resin composite was tested in a dark room at 23 degrees C by loading the samples during 60 s with 1625 g. After loading, the circumference of each sample was determined by a digitizer. Results were analyzed using Tukey-HSD multiple comparisons test and Student's t-tests. RESULTS: The consistency of different brands of composites varied considerably. P50 was the material with the thinnest consistency. Significant differences (p < 0.05) in consistency were found between the same brands of material which were applied directly out of the syringe or out of a preloaded tip. Loading a Centrix tip with one composite out of a syringe resulted in a thinner consistency of the material than when taken directly from the syringe. SIGNIFICANCE: A ranking of posterior resin composites is presented to enable a material selection based on consistency.

Cavity wall adaptation and voids in adhesive Class I resin composite restorations.

OBJECTIVES: Handling characteristics and adaptation modes of resin composites are important factors to achieve proper placement of the restorative materials. The present study was undertaken to assess the influence of the consistency of composite materials and the mode of application on voids and porosities in Class I adhesive restorations. METHODS: One hundred medium-sized Class I preparations with an adhesive design were restored with three composites of various consistencies using three different application modes. The restorations were sectioned, and each section of a restoration was inspected for the presence of voids. The total surface and the percentage of the cavity wall occupied by voids as well as the total number of voids in the sections were recorded. A Krusal-Wallis analysis of variance was carried out on the data. Differences between individual composite materials for each mode of application and between individual application modes for each composite material were analyzed using a Mann-Whitney U-test at p < 0.05. RESULTS: The injection technique with a Hawe Neos Centrix tip was the best mode of application. Both smearing and the condensation of composites appeared to produce unreliable results. Furthermore, there were more problems with voids and wall adaptation for the thicker-consistency composite than for the medium- and thin-consistency material. SIGNIFICANCE: The thick-consistency composite had more problems related to voids and wall adaptation than the medium- and thin-consistency composites.

Clinical evaluation of Dyract in primary molars: 1-year results.

PURPOSE: To evaluate the 1-year clinical performance of Dyract in primary molars. MATERIALS AND METHODS: 55 children (aged 4-9 years) received 1-3 restorations (n = 91) utilizing Dyract, a new restorative material combining properties of both glass ionomers and composites. RESULTS: The so-called compomer material showed good handling characteristics and a survival rate of 97% after 1 year. Nevertheless, the material demonstrated an average wear of 190 microns during 1 year, with 67% of the restorations having occlusal wear of less than 200 microns. The combination of a low failure rate and the ease of application makes the compomer material very suitable for application in the primary dentition.

The need for general anesthesia for the dental treatment of mentally handicapped patients: a follow-up study.

Over a period of years, it appeared possible to provide routine treatment without the use of general anesthesia for nearly all of the patients. The majority required treatment under general anesthesia because of their lack of previous dental care.