A Novel Concept for Developing a Precise and Predictable Post and Core Complex Using the Injectable Resin Technique (Part 2).

Post and core systems have long been used in dentistry for the purposes of replacing missing coronal tooth structure, retaining the core, and providing sufficient retention and resistance form to the final restoration to re-establish original form and function. While Part 1 of this two-part article provided a history of post and core systems and materials and discussed empirical data regarding fiber-reinforced post systems, this second part of the article focuses on an alternative approach for developing a fiber-reinforced post and core system using a monoblock system via the injectable resin technique and a recently developed fiber-optic post. The present article explains the concept of a ferrule effect and demonstrates the novel restorative procedure.

A Novel Concept for Developing a Precise and Predictable Post and Core Complex Using the Injectable Resin Technique.

Post systems have long been used in the roots of teeth to retain dental restorations. The primary objectives of current post and core systems are to replace missing coronal tooth structure, retain the core, and provide sufficient retention and resistance form to the final restoration to restore original form and function. Many varieties of user-friendly post and core systems are available today for different endodontic, restorative, and esthetic requirements.

In vitro inhibition of demineralization from bioglass-containing adhesive and composite.

Purpose: To measure and compare the area of inhibition around a bioglass-containing adhesive and resin-based composite following an in vitro artificial caries model in human extracted teeth.

Methods: Preparations were made at the CEJ of extracted human molars (40, n=10/material) and restored with combinations of a bioglass-containing adhesive (BA, Regen), a reference adhesive which served as a negative control (RA), a bioglass-containing composite (BC, Regen), and a reference composite which served as a negative control (RC): BABC, RABC, BARC, RARC. All materials were light-cured and then finished with a polishing disc.

Effect of Surface Treatment and Cement on Fracture Load of Traditional Zirconia (3Y), Translucent Zirconia (5Y), and Lithium Disilicate Crowns.

Purpose: To determine if surface treatment and cement selection for traditional 3 mol% yttria partially stabilized zirconia (3Y-PSZ), "translucent" 5 mol% yttria-stabilized zirconia (5Y-Z), or lithium disilicate crowns affected their fracture load.

Materials And Methods: Crowns with 0.8 mm uniform thickness (96, n = 8/group) were milled of 3Y-PSZ (Lava Plus), 5Y-Z (Lava Esthetic), or lithium disilicate (e.

Comparison of the mechanical properties of translucent zirconia and lithium disilicate.

Statement Of Problem: Three mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) possesses excellent mechanical properties but is relatively opaque. Five mol% yttria-stabilized zirconia polycrystal (5Y-ZP) offers improved translucency, but many of its clinical properties have not been compared with those of 3Y-TZP and lithium disilicate.

Purpose: The purpose of this in vitro study was to compare the flexural strength, translucency parameter, bond strength, and enamel and material wear of 5Y-ZP (Katana UTML) with 3Y-TZP (Katana HT) and lithium disilicate (e.

Wear, strength, modulus and hardness of CAD/CAM restorative materials.

Objective: To measure the mechanical properties of several CAD/CAM materials, including lithium disilicate (e.max CAD), lithium silicate/zirconia (Celtra Duo), 3 resin composites (Cerasmart, Lava Ultimate, Paradigm MZ100), and a polymer infiltrated ceramic (Enamic).

Methods: CAD/CAM blocks were sectioned into 2.

Light-transmitting fiber optic posts: An in vitro evaluation.

Statement Of Problem: The clinical challenge of adhering cement to intracanal dentin is transmitting light to the most apical parts of root canals to allow more efficient polymerization of the cement.

Purpose: The purpose of this in vitro study was to compare the cement-polymerizing ability, microstructure, and radiopacity of a new fiber optic post (iLumi fiber optic Post) with a clinically successful fiber post (DT Light Post).

Material And Methods: Polymerizing ability was compared using a modified depth-of-polymerization protocol.

Microleakage around Class V Composite Restorations after Ultrasonic Scaling and Sonic Toothbrushing around their Margin.

Objectives: To measure microleakage around class V composite restorations after piezoelectric ultrasonic scaling and sonic toothbrushing.

Methods: 3 mm × 2 mm × 1.5 mm boxes were prepared on buccal and lingual surfaces of extracted molars centered on the cementum-enamel junction.

Depth of cure of bulk fill composites with monowave and polywave curing lights.

Purpose: To measure and compare the depth of cure (DOC) of two bulk fill resin composites using a monowave and polywave light curing unit (LCU) according to ISO 4049 and using custom tooth molds.

Methods: The DOC of Tetric Evoceram Bulk Fill and Filtek Bulk Fill Posterior were measured using a monowave LED LCU (Elipar S10) and a polywave LED LCU (Bluephase G2). Metal molds were used to fabricate 10 mm long DOC specimens (n = 10) according to ISO 4049.

Cleaning Methods for Zirconia Following Salivary Contamination.

Purpose: To determine the best method of cleaning saliva-contaminated zirconia in preparation for resin bonding.

Material And Methods: Flat blocks of zirconia were particle abraded with aluminum oxide and divided into eight groups (n = 10). Groups 1 to 4 were first treated with one coat of an MDP primer (Z-prime Plus) and groups 5 to 8 were left untreated.

Factors influencing the progression of noncarious cervical lesions: A 5-year prospective clinical evaluation.

Statement Of Problem: The etiology (chemical, friction, abfraction) of noncarious cervical lesion (NCCL) progression is poorly understood.

Purpose: The purpose of this 5-year prospective clinical trial was to measure the relationship between NCCLs and various etiologic factors.

Material And Methods: After review board approval, 29 participants with NCCLs were enrolled.

Effect of grain size on the monoclinic transformation, hardness, roughness, and modulus of aged partially stabilized zirconia.

Objective: Low-temperature-degradation (LTD) has been reported to cause property changes in yttria-tetragonal zirconia polycrystals (Y-TZP). The current study measured monoclinic phase transformation of Y-TZP with different grain sizes and corresponding property changes due to artificial aging.

Null Hypothesis: the grain size of aged Y-TZP will not influence its transformation, roughness, hardness or modulus of elasticity.

Two-year clinical trial of a universal adhesive in total-etch and self-etch mode in non-carious cervical lesions.

Objectives: To compare the clinical performance of Scotchbond™ Universal Adhesive used in self- and total-etch modes and two-bottle Scotchbond™ Multi-purpose Adhesive in total-etch mode for Class 5 non-carious cervical lesions (NCCLs).

Methods: 37 adults were recruited with 3 or 6 NCCLs (>1.5mm deep).

Contact angle of unset elastomeric impression materials.

Statement Of Problem: Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed.

Purpose: The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing.

Gloss and Stain Resistance of Ceramic-Polymer CAD/CAM Restorative Blocks.

Objective: To evaluate the gloss and stain resistance of several new ceramic-polymer CAD/CAM blocks

Materials And Methods: Specimens (4 mm) were sectioned from: Enamic (polymer-infused ceramic), LAVA Ultimate (nano-ceramic reinforced polymer), e.max (lithium disilicate), Paradigm C (porcelain), and Paradigm MZ100 (composite). Specimens were wet polished on a polishing wheel to either 320 grit silicon paper (un-polished, N = 8) or 2000 grit silicon carbide papers followed by a 0.

Fracture load of ceramic restorations after fatigue loading.

Statement Of Problem: A clinician must decide what ceramic coping and veneer material to prescribe based on the amount of tooth reduction possible and the desired esthetic outcome of the restoration.

Purpose: The purpose of this in vitro study was to compare the fracture strength of monolithic and bilayered lithium disilicate (IPS e.max) and zirconia (LAVA) crowns at clinically relevant thicknesses after load cycling.

Clinicians reaping benefits of new concepts in impressioning.

While conventional elastomeric impression materials are still being used to generate excellent impressions, the future of impression-taking is undoubtedly with digital intraoral scanners. Advances in scanning systems are making this technology easier to use and more practical for dentists.

Bonding a veneered zirconia anterior fixed partial denture.

This case report documents the rationale and procedure for bonding a veneered zirconia restoration. A three-unit zirconia fixed partial denture (FPD) was fabricated with facial and incisal porcelain veneering. The intaglio surface of the prosthesis was abraded with 50-μm aluminum oxide (Al2O3) particles and coated with one layer of a 10-methacryloxydecyl dihydrogen phosphate (MDP) primer.

Phase transformation of dental zirconia following artificial aging.

Aims: Low-temperature degradation (LTD) of yttria-stabilized zirconia can produce increased surface roughness with a concomitant decrease in strength. This study determined the effectiveness of artificial aging (prolonged boiling/autoclaving) to induce LTD of Y-TZP (yttria-tetragonal zirconia-polycrystals) and used artificial aging for transformation depth progression analyses. The null hypothesis is aging techniques tested produce the same amount of transformation, transformation is not time/temperature dependent and LTD causes a constant transformation throughout the Y-TZP samples.

Color and Gloss of Nano-Filled Resin-Modified Glass Ionomers and Resin Composites.

Objective: The study aims to compare in vitro stain resistance, color stability, gloss, and gloss retention of a nano-filled resin-modified glass ionomers (RMGIs) to a traditional RMGI and resin-based composites (RBCs).

Materials And Methods: Specimens (N = 20) were fabricated from a nano-filled RBC (Filtek Supreme Plus, 3M ESPE, St. Paul, MN, USA), a nanohybrid RBC (Clearfil Majesty Esthetic, Kuraray; Tokyo, Japan), a nano-filled RMGI (Ketac Nano, 3M ESPE), and traditional RMGI (Fuji II LC, GC America, Chicago, IL, USA).

Wear of enamel opposing zirconia and lithium disilicate after adjustment, polishing and glazing.

Objectives: To compare the wear and opposing enamel wear of adjusted (A); adjusted and polished (AP); and adjusted and glazed (AG) zirconia and lithium disilicate.

Methods: Specimens (n=8) were prepared of lithium disilicate (A, AP, and AG), zirconia (A, AP, and AG), veneering porcelain, and enamel (control). Surface roughness was measured for each ceramic.

Influence of particle abrasion or hydrofluoric acid etching on lithium disilicate flexural strength.

Statement Of Problem: Lithium disilicate is a translucent, glass-containing material used for ceramic restorations. Clinicians frequently use alumina abrading or hydrofluoric acid etching to create micromechanical retention in the intaglio surface before bonding a lithium disilicate restoration to the tooth. Few studies have investigated how the etching or abrasion processes affect the flexural strength of lithium disilicate ceramics.

Wear of nanofilled dental composites at varying filler concentrations.

The aim of this study is to examine the effects of nanofiller concentration on the mechanisms of wear of a dental composite. Nanofilled composites were fabricated with a bisphenol A glycidyl methacrylate polymer and 40 nm SiO2 filler particles at three filler loads (25, 50, and 65 wt %). The elastic modulus, flexural strength, and hardness of the composites and the unfilled resin were measured.