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J W Reinhardt

Publications and source records attributed to J W Reinhardt.

44 records · Page 3Linked to original sources
PubMedDate not supplied

A national survey on the use of glass-ionomer cements.

This study was conducted to determine why and how glass-ionomer cements are being used by general dentists. Data were collected by a mail survey sent to a random sample of approximately 1000 general dentists in the United States. The results showed that 94% of the respondents currently use or have used glass ionomers. The primary uses (in order of popularity) are: 1) as a base or liner, 2) as a luting cement, and 3) as a crown foundation. Eighty-two percent of the respondents who use glass-ionomer luting cements reported some postoperative tooth sensitivity, but a slightly larger proportion (85%) reported postoperative sensitivity with other cements.

Cementation↗
PubMedDate not supplied

Effects of secondary curing on indirect posterior composite resins.

This study was designed to compare strength, elastic modulus (stiffness), and hardness for five composite resin materials that are used for laboratory-fabricated posterior composite restorations. Ten specimens of each material were processed according to the manufacturer's instructions. Statistical analysis indicated that there were significant differences in mechanical properties among the materials tested. In addition, materials that are incrementally light cured prior to secondary processing were tested for changes in mechanical properties following secondary processing. It was determined that secondary processing provided improvement in flexural strength (11%) when compared to samples that were only light cured.

Acrylic Resins↗
PubMedDate not supplied

Enhancement of resin bonding to heat-cured composite resin.

The purpose of this study was to evaluate the effectiveness of various surface treatments used to enhance the bond strength of resin cements to two different laboratory-processed composite resins. Seventy specimens of a microfilled composite resin (Concept) and 70 specimens of a micro-hybrid composite resin (Herculite XRV) were fabricated in metal wells and subjected to heat (250 degrees F) and pressure (85 psi) curing. An additional 70 specimens of each material were fabricated in the shape of disks and also subjected to the same heat/pressure curing. All composite resins were subjected to one of seven treatment regimens. The like-treated specimens were then bonded together using dual-curing resin cement and a uniform seating force (106 gm). After 7 days, bonded specimens were thermocycled 1000 times at 5 and 55 degrees C, and debond shear strengths were determined on a Universal Testing Machine. The use of microabrasion (50 microns aluminum oxide at 60 psi) and ceramic layer deposition (30 microns aluminum oxide with a ceramic additive at 75 psi) consistently improved the shear bond strength of the resin cements to both composite resins. The other treatment combinations provided varying effects. In conclusion, microabrasion or ceramic layer deposition are preferred methods to enhance the bond of resin cements to composite resins.

Acid Etching, Dental↗
PubMedDate not supplied

Shear bond strengths of 10 adhesive resin/amalgam combinations.

This study compared the shear bond strengths of amalgam to dentin using two amalgam alloys and five adhesive resin systems. One hundred extracted human third molars were flattened occlusally to expose dentin. Dentin surfaces were treated with one of five adhesive resins: All-Bond 2, Amalgambond Plus, Amalgambond Plus with HPA Powder, OptiBond, and Resinomer. Tytin (spherical) or Dispersalloy (admixed) amalgam was condensed onto the treated dentin surface through a Teflon split mold. The samples were stored 7-10 days and thermocycled before shear testing using a Zwick Materials Testing Machine. Two-way ANOVA revealed significant differences among the 10 groups (P < 0.05). The combination of Tytin/OptiBond produced the highest bond strength to dentin (14.17 MPa), while Dispersalloy/Amalgambond Plus produced the lowest (3.89 MPa). In general, the filled resin systems (Amalgambond Plus with HPA Powder, OptiBond, Resinomer) produced higher bond strengths than the unfilled systems (All-Bond 2, Amalgambond Plus). Additionally, for four of the five resins, bond strengths were higher with Tytin than with Dispersalloy, although differences were statistically significant in only two groups.

Adhesives↗