Accuracy of maxillary full-arch digital impressions of tooth and implant models made by two intraoral scanners.

Objectives: Limited studies are available on the accuracy of intraoral scanners (IOSs) for full-arch implant and tooth models. This study aimed to assess the accuracy of maxillary full-arch digital impressions of tooth and implant models made by two IOSs.

Materials And Methods: This in vitro, experimental study was conducted on two maxillary dentiform models: one with six prepared natural teeth and the other with six implants at the site of canine, first premolar, and first molar teeth, bilaterally.

Reconstruction of Gingival Mask around CAD-CAM Bar and Ball Attachment in Implant-Retained Overdenture.

Gingival mask is a copy of the peri-implant tissue, which plays an important role in the fabrication of an optimal restoration. Losing the gingival mask is a clinical problem that complicates the process of restoration fabrication. Herein, a simple precise technique is described step by step to solve this problem in the patient with CAD/CAM milled bar and ball attachment treatment plan for a maxillary and a mandibular implant-supported overdenture, without the need to repeat the entire clinical and laboratory procedures.

Comparing the Surface Behavior of Conventional and CAD-CAM Feldspathic Porcelains in the Face of Laser-Assisted Bleaching and Post-bleach Polishing.

The prevalence of using different esthetic methods increases the possibility of close contact between them with potential adverse interactions. This study aimed to compare the surface changes (microhardness and roughness) in two types of feldspathic porcelain after laser bleaching and post-bleach polishing. 12 standardized rectangular specimens were prepared for each porcelain group (conventionally layered and CAD-CAM milled).

Evaluation of the colour and translucency parameter of conventional and Computer-aided design and computer-aided manufacturing (CAD-CAM) feldspathic porcelains after staining and laser-assisted bleaching.

Aims: The present study aimed to evaluate the color and translucency changes of the feldspathic porcelain samples made using the conventional or computer-aided design/computer-aided manufacturing (CAD/CAM) methods after immersion in staining solutions and laser bleaching.

Materials And Methods: A total of 72 samples of feldspathic porcelain were fabricated using the conventional ( = 36) or CAD/CAM ( = 36) methods. Afterward, each group was randomly divided into three subgroups ( = 12), which underwent exposure to coffee, orange juice, or distilled water for 6 weeks.

Comparison of retention and fracture load of endocrowns made from zirconia and zirconium lithium silicate after aging: an in vitro study.

Background: This study aimed to compare retention and fracture load in endocrowns made from translucent zirconia and zirconium lithium silicate.

Methods: Fifty-six intact human maxillary molars after being mounted in acrylic resin, were scanned to acquire biogeneric copies. Specimens underwent standard endodontic treatment and were prepared for endocrown up to 2 mm above the cementoenamel junction.

Evaluation of the effect of milling mode and margin definition on adaptation of chairside digitally designed and fabricated ceramic veneers.

Aim: The present study aimed to evaluate the effect of the milling mode and margin defining method on the marginal and internal adaptation of digitally designed and fabricated ceramic veneers.

Materials And Methods: Forty extracted central incisors were prepared for ceramic veneers. The veneers were categorized into four groups (n = 10) based on the milling mode (fine or extra-fine) and design (automatic or manual defining of cervical and incisal margins).

Comparison of Marginal and Internal Adaptation in Endocrowns Milled from Translucent Zirconia and Zirconium Lithium Silicate.

Purpose: This study aimed to compare marginal and internal adaptation in endocrowns made from translucent zirconia and zirconium lithium silicate using CAD-CAM technology.

Materials And Methods: Twenty-eight freshly extracted upper molars were mounted in acrylic resin and underwent root canal therapy and endocrown preparation up to 2 mm above the cementoenamel junction. Endocrowns were CAD-CAM milled from zirconium lithium silicate (ZLS) and translucent zirconia (Zr).

Comparison of Fracture Resistance and Failure Mode in Digitally Milled Restorations with Rapid Layering by Indirect Composite Resin: An In Vitro Study.

Purpose: To evaluate the fracture resistance and failure mode of implant crowns made by polyether ether ketone (PEEK), zirconia, and chromium-cobalt frames, veneered by milled composite resin.

Materials And Methods: Thirty-six implant analogs were mounted in acrylic blocks, and solid abutments were secured (n = 12). Single-unit frameworks were milled from PEEK, zirconia, or chromium-cobalt, and cemented to indirect composite veneers fabricated by the rapid layering technique.

Retention and Clinical Performance of Zirconia Crowns: A Comprehensive Review.

Zirconia has been used for rehabilitation of edentulous spaces approximately for a decade, and there have been several reports regarding the clinical performance and retention of zirconia crowns. Outstanding mechanical properties, biocompatibility, and excellent aesthetics make zirconia-based crowns as a popular crown among the current all-ceramic crowns in restorative dentistry. However, restoration with a zirconia crown is a challenging treatment.

Comparison of Marginal Adaptation of Different Implant-Supported Metal-Free Frameworks Before and After Cementation.

Purpose: To compare marginal adaptation before and after cementation of implant-supported metal-free frameworks fabricated from zirconia, polyetheretherketone (PEEK), or composite.

Materials And Methods: Thirty-six CAD/CAM frameworks were constructed from zirconia, PEEK, or composite (n = 12 per material). Marginal gap was measured using a Video Measuring Machine (VMM) system, and repeated-measures analysis of variance was employed for data analysis (P < .

Comparative evaluation of the effect of impression materials and trays on the accuracy of angulated implants impressions.

Background: Vinyl Polyether Siloxane is a newly introduced impression material and studies on that is scarce. Implant insertion in posterior mandible might be angulated due to anatomical considerations. The purpose of this study was to compare the dimensional and angular accuracy of impressions using full-arch versus sectional tray and Vinyl Polysiloxane versus Vinyl Polyether Siloxane in angulated implants.

The Effect of Flat Dual-Cure Stabilizer Occlusal Splint in Pain Relief of Individuals Suffering from Migraine Headaches.

Background: No study on the effect of dual-cure stabilizer splint without canine ramp in migraine patients is present.

Objective: This study was conducted to determine the effects of maxillary flat dual-cure stabilizer occlusal splint on severity, frequency and episodes of headaches in individuals suffering from a migraine.

Methods: In this interventional clinical trial, 30 eligible patients were divided into 2 groups (case and control); each group consisted of 8 men and 7 women.

Comparing Retention and Internal Adaptation of Different Implant-Supported, Metal-Free Frameworks.

Purpose: This study was conducted to compare the fit and retention of implant-supported, metal-free copings fabricated from zirconia, polyetheretherketone (PEEK), or composite, as well as to evaluate the possible correlation between internal adaptation and retention.

Materials And Methods: A total of 36 copings were milled from zirconia, PEEK, or composite blanks (n = 12 in each group). Marginal and internal gap were evaluated by replica technique, and the pull-out test was used to evaluate retention.

Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics.

Aim: Surface treatment is necessarily required for bonding of zirconia to the veneering porcelain and luting cements. Sandblasting is the most common and probably the most efficient surface treatment method. Sandblasting roughens the surface and may affect the flexural strength of zirconia.

Effect of Repeated Firings on Microtensile Bond Strength of Bi-layered Lithium Disilicate Ceramics (e.max CAD and e.max Press).

Aim: To achieve acceptable contour, color, esthetics, and occlusal relations, the porcelain may be subjected to several firing cycles. This study sought to assess the effect of multiple firing cycles on the microtensile bond strength (MTBS) of lithium disilicate-based ceramics (e.max Press, e.

Full Mouth Reconstruction of a Bruxer with Severely Worn Dentition: A Clinical Report.

Tooth wear is attributed to several factors many of which often remain unidentified. Management of tooth wear is challenging in preventive and restorative dentistry. Correct assessment of occlusal vertical dimension, interocclusal rest space, and centric relation records are critical for successful treatment.

Effect of storage time of extended-pour and conventional alginate impressions on dimensional accuracy of casts.

Objectives: Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast.

Materials And Methods: In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates.

The effect of thermocycling on tensile bond strength of two soft liners.

Objective: Failure of soft liners depends mostly on separation from the denture base resin; therefore measurement of the bond strength is very important. The purpose of this study was to compare the tensile bond strength of two soft liners (Acropars, Molloplast-B) to denture base resin before and after thermocycling.

Materials And Methods: Twenty specimens fromeach of the two different soft liners were processed according to the manufacturer's instructions between two polymethyl methacrylate (PMMA) sheets.

The effect of multiple firings on microtensile bond strength of core-veneer zirconia-based all-ceramic restorations.

Purpose: Differences in core and veneer coefficients of thermal expansion, firing shrinkage, and speed of increasing and decreasing the temperature may generate stress in veneered all-ceramic restorations. Given the necessity of performing multiple firing cycles to achieve improved contour, color, and esthetics, the purpose of this study was to determine the effect of multiple firing cycles on the microtensile bond strength (MTBS) of zirconia core to the porcelain veneer in zirconia-based all-ceramic restorations.

Materials And Methods: Thirty blocks (12 × 12 × 4 mm(3)) of semi-sintered zirconia were machined and sintered according to manufacturer's instruction.