Comparative study of collagen and expanded polytetrafluoroethylene membranes in the treatment of human class II furcation defects.

The purpose of this study was to compare the changes in clinical attachment when either a non-resorbable ePTFE membrane or an absorbable collagen membrane was used as a barrier during surgical treatment of class II molar furcation defects. Thirteen patients, mean age 43.2 years, with two comparable class II molar defects were treated using a split mouth design.

Oral mucosal biopsy procedures. Excisional and incisional.

Incisional and excisional biopsies of oral mucosal lesions are procedures the dental practitioner should employ for total patient care. Indications and contraindications for obtaining biopsy specimens are outlined in this article. Also, basic and adjunctive surgical techniques are described with an emphasis on a continuum of care until resolution.

The dimensions of the human dentogingival junction.

This study examined the naturally occurring dimensions of the dentogingival junction in 10 adult human cadaver jaws. The connective tissue attachment, epithelial attachment, loss of attachment, and sulcus depth were measured histomorphometrically for 171 tooth surfaces. Mean measurements were 1.

Fracture resistance of premolars with MOD amalgam restorations lined with Amalgambond.

A comparison was made of the fracture resistance of premolar teeth with mesial-occlusal-distal (MOD) amalgam preparations lined with either a resin containing 4-META (Amalgambond) or copal varnish (Plastodent) and restored with a spherical alloy (Tytin). Restored teeth were aged for 7 or 67 days at 37 degrees C in 100% humidity and thermocycled between 5 and 55 degrees C for 3500 cycles. There was no significant difference in the mean fracture resistance between teeth lined with Amalgambond and teeth lined with Plastodent under any of the test conditions.

Shear bond strength of resin composite to Dicor treated with 4-META.

The combination of Etch-Free Primer and C&B Metabond has been reported to produce high resin composite to feldspathic porcelain bond strengths without hydrofluoric acid etching. This study compared the shear bond strength of resin composite to a castable glass ceramic that was treated with either Etch-Free Primer and C&B Metabond or ammonium bifluoride (NH5F2) etch/silane under various surface treatment and thermal stress variables. Bond strengths after Etch-Free Primer/C&B Metabond treatment were significantly lower than those for NH5F2/silane treatment.

Interpretation of linear and computed tomograms in the assessment of implant recipient sites.

Tomography is a radiographic process that produces cross-sectional images of bony structures within the body. The purpose of this study was to evaluate the accuracy of diagnostic measurements made by dental implant team members from linear tomograms of human cadaver mandibles. Five partially edentulous cadaver mandibles were radiographed using linear tomography (LT) and computer-assisted tomography (CT).

Early erosion of glass-ionomer cement at crown margins.

This study investigated the early erosion of glass ionomer-cement that had been used to lute complete cast crowns. Restorations had margins ending on either enamel or cementum and had various sizes of marginal openings. These restorations were compared to those using a standard zinc phosphate cement.

Integrating fixed and removable provisional restorations.

When both fixed and removable components are required, provisional restorations can be difficult. This article describes a technique where provisional restoration "shells" are made with a plastic stent of the diagnostic wax-up on lightly prepared teeth of a diagnostic cast. An acrylic removable partial denture is then waxed to the shells.

Improving the accuracy of a new articulator.

The indications and features of the new Denar Combi articulator are reviewed. The Combi articulator was designed primarily as a set path instrument, but can also be used as a semiadjustable or fully adjustable stereographic articular. The articulator can be programmed for any of these modes, but the Combi model is limited when used as a stereographic instrument according to the manufacturer's instructions, with the instrument-precipitated geometric errors.

Small versus large particles of demineralized freeze-dried bone allografts in human intrabony periodontal defects.

Various particle sizes of demineralized freeze-dried bone allograft (DFDBA) are currently used to treat patients with periodontal osseous defects. However, the effect of particle size on the healing of human intrabony periodontal defects is unknown since there have been no direct clinical comparisons. The purpose of this study was to compare the bony defect resolution obtained using two different particle size ranges of DFDBA.

Repair of an aged, contaminated indirect composite resin with a direct, visible-light-cured composite resin.

This study investigated the interfacial shear bond strength of a contaminated, aged, heat- and pressure-processed, indirect composite resin (Concept) repaired with a direct, visible-light-cured composite resin (Heliomolar). Concept samples were aged by thermocycling and contaminated in tobacco juice. The bonding surfaces were prepared by sanding with 500-grit sandpaper or air abrading with 50-micron aluminum oxide.

Microleakage of a dental amalgam alloy bonding agent.

Amalgambond (a 4-META derivative resin bond agent) was evaluated for its effectiveness in reducing microleakage compared to copal varnish and no lining agent in class 5 amalgam preparations restored with either an admix alloy (Dispersalloy) or a spherical alloy (Tytin). Teeth were thermocycled between 5 and 55 degrees C with two 4-META/amalgam groups additionally aged in 37 degrees C water for 30 days prior to thermocycling. Nonaged, 4-META/amalgam restorations showed significantly less microleakage (P < 0.

Molar efficiency study of chlorinated NPG substitutes in dentin bonding.

This study evaluated and compared the contributions to dentin adhesive bonding of three N-phenylglycine analogues with electron-withdrawing substituents on the aromatic ring. These electron-deficient "N-compounds" included: N-(4-chlorophenyl)-glycine (NCPG), N-methyl-N-(4-chlorophenyl)-glycine (NMNCPG), and N-(3,4-dichlorophenyl)-glycine (NDCPG). An experimental three-step dentin-bonding protocol that consisted of sequential application of acidic ferric oxalate solution, an N-compound in acetone, and a surface-active comonomer in acetone was used.

What you don't see can hurt you.

Although AVMs are quite rare, at least two generalizations can be drawn from this case. First, don't rush into treatment. Time spent in the initial diagnosis and treatment planning is time well spent.

Microwave processing for denture relines, repairs, and rebases.

The microwave processing procedure has been shown to be an efficient and accurate method of polymerizing poly(methyl methacrylate) resin for the fabrication of dentures. This article describes procedures to expand the uses of the microwave technique. With standard laboratory procedures, the microwave technique can improve and simplify denture relines, repairs, and rebasing of partial dentures.

A comparison of polylactic acid granules and decalcified freeze-dried bone allograft in human periodontal osseous defects.

The purpose of this study was to compare the effectiveness of polylactic acid (PLA) granules as an alloplastic grafting material to that of decalcified freeze-dried bone allograft (DFDBA) and a flap procedure for debridement without graft (FPD) when treating periodontal intrabony defects. Ten patients presenting with advanced adult periodontitis, including at least 3 similar periodontal osseous defects (2- and 3-walled), comprised the study group. After completion of a hygienic phase of treatment, measurements were made with calibrated periodontal probes and stents to determine soft tissue recession, probing pocket depths, and probing attachment levels.

Using cyanoacrylate to facilitate rubber dam isolation of teeth.

Cyanoacrylate is an extremely strong bonding agent which has many applications in medicine. It is also effective in obtaining a leakproof seal of rubber dam around a structurally compromised tooth requiring endodontic therapy.

The effect of venting on the strength of Dicor and Hi-Ceram ceramic crowns.

Research has shown that external venting improves the marginal fit of cast crowns by decreasing hydrostatic pressure during seating. In turn, improving marginal fit has been shown to increase the strength of castable glass and other porcelain systems. This study evaluated the effect on the compressive strength of crowns with vent holes placed during and after fabrication.

Direct measurement of dimensional accuracy with three denture-processing techniques.

The Michigan Computer-Graphics Coordinate Measurement System (MCGCMS) was used to determine the dimensional accuracy of dentures processed by three different techniques: conventional heat compression, microwave, and visible-light activation. Standardized dentures were fabricated from casts made in an RTV silicone mold. All casts were duplicated with hydrocolloid and 42 dentures were made (ie, 14 dentures for each technique).

Effect of dentinal bonded resin post-core preparations on resistance to vertical root fracture.

An in vitro study was conducted to compare the resistance to failure of two restorative protocols for endodontically treated teeth. Half of 24 specimens received cemented cast post-core restorations and the other half were restored with dentin-bonded composite resin using the ferric oxalate, NTG-GMA, and the PMDM system developed by Bowen. The dentin-bonded resin post-core restorations provided significantly less resistance to failure than the cemented custom cast post-core.

Stress analysis of five prefabricated endodontic dowel designs: a photoelastic study.

The stress generated by five prefabricated endodontic dowel designs was evaluated using a two-dimensional photoelastic model. Cemented posts caused the least stress. Of the threaded posts, Flexi-post and Radix Anker produced the least stress; Kurer Crown Anchor produced the most.

The effect of slot preparation length on the transverse strength of slot-retained restorations.

An in vitro study was conducted (1) to compare fracture strength of amalgam restorations retained with retentive slots of different lengths when stressed with a transverse force, (2) to determine if beveling the slot preparation resulted in an increase in fracture resistance to a transverse force, and (3) to evaluate the incidence of unrestorable tooth fracture as it relates to slot preparation length. Six groups of 10 specimens were prepared with slots of increasing length, with each specimen receiving four slots of equal length. Slot preparations in group 6 were beveled.

Utilization of an oral pathology service: a professional responsibility.

The role of oral pathologists as members of the comprehensive health care team is reviewed. The importance of utilizing an Oral Pathology Service in the everyday practice of dentistry and medicine and the inherent medicolegal considerations are discussed. Standards of care for submission of surgically removed oral tissues is an issue that warrants further delineation.

Reconstruction of root morphology in skeletonized remains with postmortem dental loss.

A reversible technique is presented in which the root morphology of missing teeth in skeletonized human remains can be reconstructed for the purpose of radiographic comparison and postmortem identification. In this technique, which is based upon pilot studies with skeletonized mandibles of archival remains, the alveolar socket walls are sealed with a coat of cyanoacrylate cement and injected with a mixture of vinyl polysiloxane and barium sulfate. Radiographs are produced with the radiopaque mixture in place, which highlights the antemortem morphology of the roots.