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N J Opdam

Publications and source records attributed to N J Opdam.

15 recordsLinked to original sources
PubMed2003

[The direct composite crown].

The direct composite crown is a restoration replacing the original toothcrown in form and function. It can be an alternative for indirect gold or porcelain restorations if the oral health condition is not stable, if indirect restorations require a high biological price or if financial resources are limited. The longterm durability of these restorations is still unknown. As a direct composite crown can be considered as minimally invasive and can be easily replaced by an indirect restoration if needed, there are hardly any contra-indications for its use.

Adult↗
PubMed2001

[Repair and revision 2. Repair or replacement of composite].

Nowadays adhesive techniques enable the dentist to preserve sound tooth tissue as only decay has to be removed when a carious lesion has to be restored. Also, when an existing composite resin restoration shows a defect, a total replacement is not always necessary and a repair can be made. Specific techniques for repairing old composite resin restorations are etching with hydrofluoridic acid, sandblasting and application of a silane solution. The decision between repair or replacement is made based on the quality of the existing restoration, the needed repair strength, the biological price of a total replacement and the skills of the operator. Some case reports are added as illustrations.

Adult↗
PubMed1998

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.

Analysis of Variance↗
PubMed1998

A radiographic and scanning electron microscopic study of approximal margins of Class II resin composite restorations placed in vivo.

INTRODUCTION: Clinical studies on the quality of Class II amalgam and resin composite restorations frequently report defective cervical margins. AIM: The aim of this study was to evaluate the quality of the approximal margins of Class II resin composite restorations placed in vivo using various application techniques and adhesive systems. MATERIALS AND METHODS: Class II restorations were placed in premolar teeth in vivo, using different adhesive systems and application techniques. After extraction of the teeth, the restorations were evaluated radiographically and by SEM. RESULTS: One-hundred and forty-four resin composite Class II restorations were evaluated. According to the radiographs, 4% of the restorations were overfilled and 33% were underfilled. SEM pictures revealed that 43% of the restorations were overfilled and 25% underfilled. Thirty-two per cent of the restored teeth showed a flash of bonding agent on the approximal surface. CONCLUSIONS: Class II resin composite restorations placed in vivo may be found frequently to show imperfect cervical margins. Overextended margins observed by SEM are difficult to detect on radiographs. When seen on a radiograph, a thick layer of bonding agent may be interpreted as an underfilled restoration.

Acid Etching, Dental↗
PubMed1998

Marginal integrity and postoperative sensitivity in Class 2 resin composite restorations in vivo.

INTRODUCTION: Problems that may arise in resin composite Class 2 restorations include microleakage and postoperative sensitivity. However, limited in-vivo research is conducted to evaluate these processes. AIM: The aim of this study was to assess postoperative sensitivity, microleakage and the pooling of adhesives in relation to Class 2 box-type composite restorations placed in vivo using various adhesive systems and application techniques. MATERIALS AND METHODS: One hundred and forty-four Class 2 box restorations were placed in the mesial and distal surfaces of 72 premolar teeth in-vivo using one of three combinations of adhesive systems and three filling techniques. After 6 weeks of clinical service postoperative sensitivity was recorded. The teeth were then extracted, immersed in a dye solution and sectioned. Microleakage and pooling of the adhesive was recorded. Statistical analysis involved logistic regression and chi2 tests to identify differences between groups at p < 0.05. RESULTS: Of the 144 restorations, 65 showed minimal cervical leakage in enamel, 5 suffered leakage into dentin and 74 were free of microleakage. No statistically significant differences were found in cervical microleakage between the adhesive systems or between filling procedures. Occlusal microleakage in the enamel was present in 16 of the 160 restorations. Liner Bond 2 restorations leaked significantly more at the occlusal surface (p < 0.05). Pooling of the adhesive was significantly less when PhotoBond was used. No spontaneous postoperative sensitivity was reported. Twenty-eight restorations were sensitive to loading. Postoperative sensitivity was significantly less in patients with Liner Bond 2 restorations. CONCLUSIONS: The adhesive systems used in this study showed minimal leakage into dentin in vivo. Using Liner Bond 2, restorations exhibited more occlusal leakage but were significantly less sensitive to loading.

Adhesives↗
PubMed1998

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.

Acid Etching, Dental↗
PubMed1998

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.

Acid Etching, Dental↗
PubMed1997

Adaptation and radiographic evaluation of four adhesive systems.

OBJECTIVES: The purpose of this study was to compare microleakage, gap formation, thickness of the adhesive layer and its radiographic appearance associated with four adhesive restorative procedures for class I cavities. METHODS: Adhesive systems with easy handling characteristics were selected for the restoration of class I cavities in extracted third molars. Bitewing radiographs were taken of each tooth and four observers were asked to assess the presence of the adhesive layer. Microleakage, gap width and the thickness of the adhesive layer of each restoration were measured upon sectioning of the teeth. RESULTS: Microleakage in the experimental restorations was minimal. The thickness of the adhesive layers and gap formation varied among different adhesive systems. The adhesive system with self-etching primer produced the highest percentage gap-free restorations. Thick adhesive layers could be detected on the radiograph. ROC analysis of the results validates the diagnosis from the radiograph. CONCLUSIONS: The four restorative systems performed well in the prevention of microleakage. The use of a resin modified glass-ionomer cement base did not prevent gap formation compared with the all-etch bonding systems used in this study. The presence of an adhesive layer contributed to the prevention of gap formation, independently of the bonding system used. Thick adhesive layers could be detected on the radiograph.

Acid Etching, Dental↗
PubMed1996

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.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1996

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.

Bicuspid↗
PubMed1996

[Preparation forms and filling techniques for posterior composite restorations].

The operator is a very important factor in achieving high quality posterior composite resin restorations. Specific clinical procedures are required to obtain a clinical successful restoration. Tooth saving preparations are made when primary caries is treated. However, tunnel preparations have major disadvantages. The application of a liner or base under a composite restoration is not required anymore since it does not improve the marginal seal when using an total-etch adhesive. The handling and application of the composite should be done with an injection technique and in layers, whereas low viscous composites are giving the best results in preventing voids.

Composite Resins↗
PubMed1993

[Dental fillings].

Explore the source record for details and available documents.

Dental Amalgam↗
PubMed1992

[Composite or amalgam? Not a black or white decision].

Amalgam as a restorative material in dentistry is discussed because of believed toxic properties of the material, yet there is no scientific prove for the assumption. Adhesive restorations are a possible alternative for amalgam in restoring posterior teeth. For treatment of primary caries, the direct composite resin restoration has many advantages. When greater defects are to be restored, adhesive composite resin restorations become less favourable. At this moment no long term results are available for indirect adhesive techniques. For the time being it seems necessary to use composite resin as well as amalgam for the restoration of posterior teeth.

Adhesives↗