Tooth Anatomy Inspector: A comprehensive assessment of an extended reality (XR) application designed for teaching and learning of root canal anatomy by students.

Aim: To develop and evaluate a suitable software application for mobile devices designed for teaching root canal anatomy to undergraduate students in an informative and engaging manner.

Methodology: Extracted human teeth were scanned by μCT and digitized by converting into STL files. An extended reality (XR) application illustrating the root canal anatomy of the scanned teeth was developed.

Impact of varnishing, coating, and polishing on the chemical and mechanical properties of a 3D printed resin and two veneering composite resins.

Statement Of Problem: Three-dimensional (3D) printing enables the fast fabrication of definitive fixed dental prostheses (FDPs). However, data on the effects of surface treatments on their chemical and mechanical properties are lacking.

Purpose: The purpose of this in vitro study was to examine the influence of different surface treatments on a 3D printed resin in comparison with 2 veneering composite resins.

Comparing accuracy in guided endodontics: dynamic real-time navigation, static guides, and manual approaches for access cavity preparation - an in vitro study using 3D printed teeth.

Objectives: To assess root canal localization accuracy using a dynamic approach, surgical guides and freehand technique in vitro.

Materials And Methods: Access cavities were prepared for 4 different 3D printed tooth types by 4 operators (n = 144). Deviations from the planning in angle and bur positioning were compared and operating time as well as tooth substance loss were evaluated (Kruskal-Wallis Test, ANOVA).

A New Implant System with Directly Screwed Supraconstructions: Impact of Restoration Material and Artificial Aging on the Bending Moment.

Purpose: To investigate the bending moment of implants restored with a directly screwed single-unit fixed dental prosthesis (FDP) compared to implants restored with an FDP polymerized to a titanium base before and after thermomechanical aging.

Materials And Methods: A total of 240 implants (120 with and 120 without a titanium base) were restored with FDPs manufactured from conventionally sintered 3Y-TZP, 5Y-TZP, 4Y-TZP, and CoCrMo, as well as high-speed sintered 4Y-TZP. Half the specimens per subgroup were aged using chewing simulation combined with thermocycling (1,200,000 cycles at 50 N; 6,000 cycles at 5° to 55°).

Fracture toughness, work of fracture, flexural strength and elastic modulus of 3D-printed denture base resins in two measurement environments after artificial aging.

Objectives: To investigate the fracture toughness (K), work of fracture (WOF), flexural strength (FS) and elastic modulus (E) of four additively manufactured denture base resins in two different measurement environments after artificial aging.

Methods: Rectangular specimens in two different dimensions (n = 480) were 3D-printed with four denture base resins: Denture 3D+ (DEN; NextDent), Fotodent Denture (FOT; Dreve ProDiMed), Freeprint Denture (FRE; Detax), V-Print dentbase (VPR; VOCO)). K, WOF, FS and E were measured after (1) water-storage (37 °C; K = 7 d; FS = 50 h); (2) water-storage + hydrothermal-aging (20 min, 0.

Three-Dimensional Printed Resin: Impact of Different Cleaning Protocols on Degree of Conversion and Tensile Bond Strength to a Composite Resin Using Various Adhesive Systems.

The present investigation tested the effect of cleaning methods and adhesives on the tensile bond strength (TBS) of a resin-based composite luted to a temporary 3D printed resin. Substrates (= 360) were printed using a Rapidshape D20II and cleaned with a butyldiglycol-based solution, isopropanol, or by centrifugation. Specimens were air-abraded with AlO (mean particle size 50 µm) at 0.

Root Maturation of an Immature Dens Invaginatus Despite Unsuccessful Revitalization Procedure: A Case Report and Recommendations for Educational Purposes.

Background: The clinical management of teeth with complex dens invaginatus (DI) malformations and apical periodontitis may be challenging due to the lack of routine. The aim of this case report is to describe the endodontic treatment of an immature tooth with DI and to discuss strategies for preclinical training for teeth with such malformations.

Case Report: A 9-year-old male presented with an immature maxillary incisor with DI (Oehlers Type II) and apical periodontitis which was diagnosed by cone beam computed tomography (CBCT).

Bond strength between temporary 3D printable resin and conventional resin composite: influence of cleaning methods and air-abrasion parameters.

Objectives: The influence of different cleaning methods, air-abrasion parameters, and aging on shear bond strength (SBS) and tensile bond strength (TBS) of 3D resin luted to composite resin.

Materials And Methods: Nine hundred resin substrates were 3D printed (D20II, Rapid Shape) and cleaned with either isopropanol (ISO), butyldiglycol-based solution (BUT), or centrifugation (CEN). After 24-h storage in 37 °C water, specimens were air-abraded (mean particle size 50 µm; n = 60) with either alumina at 0.

Water sorption, water solubility, degree of conversion, elastic indentation modulus, edge chipping resistance and flexural strength of 3D-printed denture base resins.

Objectives: To investigate the water sorption (w), water solubility (w), degree of conversion (DC), elastic indentation modulus (E), edge chipping resistance (ECR) and flexural strength (FS) of 3D-printed, milled and conventionally polymerized denture base resin materials.

Methods: Specimens (N = 540) were 3D-printed (NextDent Denture 3D+ (DEN), Fotodent Denture (FOT), Freeprint Denture (FRE), V-Print dentbase (VPR)), cut (Ivotion Base (IVO)) and molded (PalaXpress (PAL)) in three geometries. WwDC, E, ECR and FS were tested initially (24 h, 37 °C, H20) and after additional aging (5000 thermal cycles, 5/55 °C).

Bending moment of implants restored with CAD/CAM polymer-based restoration materials with or without a titanium base before and after artificial aging.

Objectives: To test and compare two types of implant systems restored with four monolithic polymer-based materials with regard to their bending moments (BM) before and after aging.

Methods: A total of 192 tissue-level implants (TRI Dental Implants) differing in the presence (TiB, Octa line, n = 96) or absence (NTiB, Matrix line, n = 96) of a titanium base were restored with mandibular right first molar crowns manufactured from composite (CC), polymer-infiltrated ceramic (VE), PMMA (PM) and a 3D printed resin (ND) (n = 24). Half of the specimens (n = 12) were loaded for 1,200,000 cycles (50 N, 1.

Methodology investigation: Impact of crown geometry, crown, abutment and antagonist material and thermal loading on the two-body wear of dental materials.

Objectives: To investigate the impact of crown geometry, crown/abutment/antagonist material and thermal loading on the two-body wear of dental materials caused by chewing simulation.

Materials And Methods: For the crown geometry, crowns (polymethylmethacrylate (PMMA), polyetheretherketone (PEEK) and silicate ceramic (SiO)) were milled with a flat, steep, or medium cusp inclination (CINC). For the crown/abutment material, crowns (PMMA, PEEK and SiO) were combined with PMMA, polymer-infiltrated-ceramic-network (PICN), cobalt-chrome alloy (CoCr) and natural teeth (ENAM) abutments.

Postpolymerization of a 3D-printed denture base polymer: Impact of post-curing methods on surface characteristics, flexural strength, and cytotoxicity.

Objective: This study investigated the influence of postpolymerization of a three-dimensional (3D) printed denture base polymer. The effect of post-curing methods on surface characteristics, flexural strength, and cytotoxicity was evaluated.

Methods: A total of 172 specimens were additively manufactured using one denture base material (V-Print dentbase, VOCO) and further post-cured by different light-curing devices, including Otoflash G171 (OF), Labolight DUO (LL), PCU LED (PCU), and LC-3DPrintbox (PB), respectively.

Influence of cleaning methods after 3D printing on two-body wear and fracture load of resin-based temporary crown and bridge material.

Objectives: To investigate the impact of different cleaning methods on the fracture load and two-body wear of additively manufactured three-unit fixed dental prostheses (FDP) for long-term temporary use, compared to the respective outcomes of milled provisional PMMA FDPs.

Materials And Methods: Shape congruent three-unit FDPs were 3D printed using three different resin-based materials [FPT, GCT, NMF] or milled [TEL] (N = 48, n = 16 per group). After printing, the FDPs were cleaned using: Isopropanol (ISO), Yellow Magic 7 (YEL), or centrifugal force (CEN).

Food Solutions and Cigarette Smoke-Dependent Changes in Color and Surface Texture of CAD/CAM Composite Resins-An In Vitro Study.

Purpose: To investigate the discoloration and surface properties of four CAD/CAM composite resins following storage in various food solutions and exposure to cigarette smoke.

Materials And Methods: A total of 74 specimens (N = 370) were prepared for five materials: Brilliant Crios (BC), Cerasmart (GC), Lava Ultimate (LU), Shofu Block HC (SH), and Sonic Fill 2 (SO). Discoloration (ΔE) was investigated with a spectrophotometer.

Temporary 3D printed fixed dental prosthesis materials: Impact of post printing cleaning methods on degree of conversion as well as surface and mechanical properties.

Purpose: To investigate the influence of different cleaning methods for additively manufactured fixed dental prostheses (FDPs) for long-term temporary use on the degree of conversion (DC), surface roughness, Martens parameters, and biaxial flexural strength.

Materials And Methods: A total of 180 specimens per material (3Delta Etemp, DeltaMed; Freeprint Temp, Detax; Temp PRINT, GC Europe; Temp C&B and C&B MFH, NextDent; N = 180) were additively manufactured (D20 II, Rapid Shape) and subsequently cleaned by different methods: by rinsing for 5 minutes in acetone (Höfer Chemie; 99.5%); butyl glycol (Algin Chemie; 100%); ethanol (Otto Fischar; 96%); isopropanol (SAV LP; 100%); Yellow Magic 7 (Bradley Systems; 100%); or by applying centrifugal force for 4 minutes (n = 30 per subgroup).

Impact of high-speed sintering on accuracy and fit of 4 mol% yttria-stabilized tetragonal zirconia polycrystals (4Y-TZPs).

Purpose: To investigate the impact of high-speed sintering on the accuracy (trueness and reproducibility) and fit of 4Y-TZP full-coverage single-unit fixed dental prostheses (FDPs) and three-unit FDPs.

Materials And Methods: Single-unit FDPs, conventional three-unit FDPs, and cantilever three-unit FDPs (N = 108; n = 12 per subgroup) were fabricated from: (1) high-speed sintered (1,580°C, about 20 minutes) multi-layer 4Y-TZP (Zolid RS, Amann Girrbach; ZMLH group), as well as two conventionally sintered (1,450°C, about 10 hours) materials: (2) multi-layer 4Y-TZP (Zolid Gen-X, Amann Girrbach; ZMLC group) and (3) monochrome 4Y-TZP (Ceramill Zolid HT+ PS, Amann Girrbach; ZMOC group). All specimens were scanned.

Influence of 3D-printing method, resin material, and sterilization on the accuracy of virtually designed surgical implant guides.

Statement Of Problem: Three-dimensional printing has introduced new manufacturing methods. However, information on the influence of the specific printing technology, material, sterilization, and the comparison between printing and milling on the accuracy of surgical guides is lacking.

Purpose: The purpose of this in vitro study was to evaluate the influence of the manufacturing method (printing and milling), printing technology stereolithography (SLA) and digital light processing (DLP), material, and sterilization on the accuracy of digitally designed surgical implant guides.

Impact of polymerization and storage on the degree of conversion and mechanical properties of veneering resin composites.

To investigate the degree of conversion (DC), Martens hardness (HM), elastic indentation modulus (E), and flexural strength (FS) of veneering resin composites (SR Nexco Paste (NP), Ceramage Incisal (CI), Gradia Plus (GP); n=60/group) cured with different polymerization devices (bre.Lux Power Unit, Labolight DUO, Otoflash G171, LC-3DPrint Box, PCU LED; n=12/subgroup) after storage. Otoflash G171 and Labolight DUO showed increased DC/HM/E.

Influence of Different Postpolymerization Strategies and Artificial Aging on Hardness of 3D-Printed Resin Materials: An In Vitro Study.

Purpose: To investigate the influence of different postpolymerization strategies and artificial aging periods on the Martens hardness parameters of 3D-printed resin materials indicated for temporary use.

Materials And Methods: Disks made of four 3D-printed resin materials (n = 30 each) were additively manufactured and postpolymerized with three different postpolymerization devices (n = 10 specimens of each material per device). Disks cut from a prefabricated milling material served as a control.

Development and evaluation of an interdisciplinary teaching model via 3D printing.

The investigation aimed to assess the feasibility of creating an interdisciplinary training model simulating endodontic, restorative as well as implantologic treatment procedures by using 3D printing technology. A CBCT scan of the mandible of a real patient was initially taken. The generated DICOM-data were converted to a STL-file, which was further processed to design spaces for exchangeable replica teeth, a bone segment and an adapter to fix the model in a mannequin's head.

Treatment outcomes after uncomplicated and complicated crown fractures in permanent teeth.

Objectives: The objectives of this retrospective clinical study were to describe characteristics of crown fractures in permanent teeth and to investigate the survival of pulp vitality and restorations in uncomplicated and complicated crown fractures.

Materials And Methods: This retrospective study collected information from patients suffering from dental trauma who were treated between January 2004 and June 2017. The study population consisted of 434 patients (253 males/181 females; mean age 20.

Guided endodontics: a comparative in vitro study on the accuracy and effort of two different planning workflows.

Aim: To compare the accuracy and effort of digital workflow for guided endodontic access (GEA) procedures using two different software applications in 3D-printed teeth modeled to simulate pulp canal obliteration (PCO) in vitro.

Materials And Methods: 32 3D-printed incisors with simulated PCO were fabricated and mounted, four each on maxillary and mandibular study arches. Cone beam computed tomography (CBCT) and 3D surface scans were matched and used to virtually plan and prepare GEA by one operator using two different methods: 1) CoDiagnostiX (CDX; Dental Wings) with 3D-printed templates, and 2) Sicat Endo (SE; Sicat) with subtractive CAD/CAM-manufactured templates.

In vitro study on the influence of postpolymerization and aging on the Martens parameters of 3D-printed occlusal devices.

Statement Of Problem: Additive manufacturing has been proposed for the fabrication of occlusal devices. However, information about the mechanical properties of additively manufactured devices is lacking.

Purpose: The purpose of this in vitro study was to evaluate the influence of the postpolymerization unit and artificial aging on the Martens hardness (HM) and indentation modulus (E) of different 3D-printed materials in comparison with a conventionally milled material.

Accuracy of CAD/CAM-fabricated bite splints: milling vs 3D printing.

Objectives: The aim of this study was to investigate the accuracy of CAD/CAM-fabricated bite splints in dependence of fabrication method (milling vs 3D printing), positioning (horizontal vs vertical), selection of material, and method of deviation measurement.

Materials And Methods: Bite splints were 3D-printed in either horizontal or vertical position (n = 10) using four different resins (Dental LT, Ortho Clear, Freeprint Splint, V-Splint). As control, ten bite splints were fabricated by CNC milling (ProArt CAD Splint).