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.

Effects of Particle Abrasion Media and Pressure on Flexural Strength and Bond Strength of Zirconia.

Objectives: To compare the effects of particle abrasion medium and pressure on shear bond strength and biaxial flexural strength of three generations of zirconia (Lava Frame, Lava Plus, and Lava Esthetic) with the goal of optimizing the bond to zirconia.

Methods: 280 discs (14 mm diameter; 1 mm thickness) of each zirconia were milled and sintered. Specimens of each material were randomly distributed into 14 groups (n=20); half were tested for shear bond strength and half were tested for biaxial flexural strength.

Demineralization Inhibition by Two Calcium-releasing Restorative Materials.

Objective: To compare the ability of two calcium-releasing restorative materials to inhibit root dentin demineralization in an artificial caries model.

Methods And Materials: Preparations were made at the cementum-enamel junction of extracted human molars (40, n=10/material) and restored with two calcium-releasing materials (Experimental composite, Pulpdent Corporation and Cention N, Ivoclar Vivadent), a resin composite (Filtek Supreme Ultra, 3M Oral Care), and a resin-modified glass ionomer (RMGI) (Fuji II LC, GC). All materials (other than the RMGI) were used with an adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in the self-etch mode, which was light cured for 10 seconds.

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.

Silver Diamine Fluoride: A Successful Anticarious Solution with Limits.

Silver diamine fluoride (SDF) is a solution containing ionic silver, fluoride, and ammonia that arrests the progress of carious lesions and prevents the development of future caries. The silver particle extends into the dentin tubules and could create some bonding problems for subsequent composite resin restorations placed over SDF-treated darkened tooth structures. The fluoride penetrates deeper into the tooth with SDF as compared with other fluoride solutions, creating a fluoride reservoir in the tooth structure.

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 Randomized, Controlled Clinical Trial of a Flowable and Conventional Composite in Class I Restorations.

Objectives: This study evaluated the two-year clinical performance and volumetric wear of a flowable resin composite compared to a conventional highly filled composite resin in Class I restorations.

Methods And Materials: In this single-center, single-blinded, comparator-controlled clinical study (Institutional Review Board approved), 120 carious teeth distributed in 60 patients were randomly assigned to four calibrated practitioners who placed occlusal restorations (n=60 flowable and n=60 conventional composite). Direct and indirect assessment at baseline, six months, one year, and two years occurred during which the modified Cvar and Ryge criteria were evaluated.

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.