CAD-CAM Materials Research Articles

Surface Characterisation of Dental Resin Composites Related to Conditioning and Finishing.

Due to the little information related to surface processing and conditioning of resin matrix ceramic materials previous glazing, the main purpose of this in vitro study was to investigate the effect of different surface treatments on the surface morphology of different resin composite materials. Five types of resin composite CAD-CAM materials: a resin composite ceramic Vita Enamic (E) and four types of nanoparticle-filled resins, like Lava Ultimate (L), Cerasmart (C), Shofu HC (S), Hyramic (H) were taken into consideration. Specimens received the following surface treatment protocols: conventional polishing [p], polishing and glazing [pg], conditioning with CoJet [c], conditioning with CoJet and glazing [cg], sandblasting [s], sandblasting and glazing [sg], etching [e], etching and glazing [eg]. Surface roughness was analyzed for all samples and nanosurface topographic characterization was made by Atomic Force Microscopy. The highest roughness was registered for sandblasted surfaces [s], followed by tribochemical silica airborne particle abrasion [c], and etching [e]. A very strong correlated conditioning behavior of resin nanoceramic materials, like L, C and S samples was found. The microroughness decreased thus [s] > [c] > [e]. These are moderate correlated with H, and are moderate negative correlated to E, where e is more efficient. Three-dimensional images indicated visible grain boundaries after conditioning, for all materials. After polishing and glazing, surfaces became smoother. For all tested conditioning and finishing methods, surface roughness values were within clinically acceptable limits. Finishing by polishing was proved to be a good choice for all materials taken into consideration, polishing and glazing likewise, excepting Hyramic. For Enamic and Shofu HC sandblasting or tribochemical conditioning and glazing and for Hyramic polishing and glazing are not the best options, related to nanoroughness values. Referring to the nanosurface topography, for Enamic, Cerasmart and Hyramic, glazing would be the method of choice, associated with the adequate conditioning method for each material.

Redefining a Smile with Monolithic CAD-CAM Crowns - A Step-by-Step Approach

Over the past few years, dentists’ utilization of the traditional porcelain-fused-to-metal (PFM) crowns has dramatically dwindled and the utilization of metal-free crowns has swiftly increased. This is due to a new high-precision manufacturing technology, CADCAM, and new reliable materials that emerged on the horizon.

Wear of monolithic zirconia against different CAD-CAM and indirect restorative materials

Statement of problemThe wear of monolithic zirconia against enamel has been widely studied, but how zirconia affects different opposing restorative materials is not clear. PurposeThe purpose of this in vitro study was to investigate the depth of wear and volumetric loss of different restorative materials opposed by monolithic zirconia. Material and methodsSixty-six Ø10×3-mm specimens (n=11) were fabricated from monolithic zirconia, zirconia reinforced ceramic, lithium disilicate ceramic, feldspathic ceramic, ORMOCER, and ceramic optimized polymer. A 2-body pin-on-disk wear test was performed by using monolithic zirconia pins. The specimens were scanned with a noncontact profilometer after the tests. The scan parameters were a frame size area of 1.5×1.5 mm, frequency of 400 Hz, and scan sensitivity of 2 μm. After the evaluation of depth and volume loss, the specimens were analyzed with a scanning electron microscope. The Kruskal-Wallis test was used to analyze the differences in wear values across the specimen groups, and pairwise comparison tests were performed with a post hoc test (α=.05). ResultsMaximum depth of wear was 257.55 ±18.88 μm for lithium disilicate ceramic, 295.36 ±14.46 μm for zirconia reinforced ceramic, 421.82 ±214.49 μm for ORMOCER, 333.73 ±79.09 μm for ceramic optimized polymer, 146.27 ±22.86 μm for feldspathic ceramic, and 41.55 ±5.04 μm for monolithic zirconia. The depth of wear was not significantly different among lithium disilicate, zirconia-reinforced ceramic, ORMOCER, and ceramic optimized polymer (P<.05). However, the depth of wear of monolithic zirconia and feldspathic ceramic was less than that of other materials (P<.001). Volume loss of lithium disilicate was 1.68 ±0.25 mm3, 1.08 ±0.35 mm3 for zirconia reinforced ceramic, 4.29 ±2.91 mm3 for ORMOCER, 2.46 ±0.63 mm3 for resin ceramic, 1.07 ±0.09 mm3 for feldspathic ceramic, and 0.19 ±0.02 mm3 for monolithic zirconia. Feldspathic ceramic and monolithic zirconia had significantly less volume loss than the other groups (P<.001), and the difference between them for volume loss was statistically insignificant (P>.05). ConclusionsThe tested ceramic-based materials had favorable wear resistance compared with the tested composite resin–based ones. However, the ceramics tended to crack formation than the composite resins.

The efficiency of laser application for debonding laminate restorations manufactured of current CAD-CAM materials with different thicknesses.

Using lasers for adhesive restoration removal can be practical and atraumatic. The purpose of this study was to investigate Er: YAG laser exposure on debonding the adhesive cementation between enamel and feldspar ceramic, lithium disilicate-reinforced and resin nano ceramic composite laminate restorations. Vita Cerec Blocs, IPS e.max Computer-aided design (CAD). Computer-aided design and manufacturing (CAD-CAM) in full and Lava Ultimate restorative materials were chosen. The 3 × 3 mm2 standardized, 0.5-mm and 1 mm thick specimens were cemented on an enamel surface. After thermocycling, each material group was randomly divided into laser treated and control (non-laser treated) groups. Shear bond strength test was done with a universal testing machine with crosshead speed 0.5 mm/min. Factorial ANOVA Technique and TUKEY HSD multiple comparison test were used for statistical analyses. Moreover, the surface morphology of the debonded samples and the enamel was observed using a scanning electron microscope. The laser application was found to weaken the SBS values significantly (P < 0.05) for all groups; however, the most dramatic SBS decrease was observed for laser treated IPS e.max at both thicknesses. Laser treatment can serve as a practical and effective method that eliminates the risk the enamel damage and restoration fracture.

Effect of Staining and Aging on Translucency Parameter of CAD-CAM Materials.

ObjectivesTo evaluate different intervals of exposure to staining solutions and artificial aging on translucency parameter (TP00) of CAD-CAM materials.Material and MethodsOne millimeter thick square-shaped specimens (N = 288) were cut from Cerasmart (CS), IPS e.max (IE), Lava Ultimate (LU), Shofu HC (SH), Vita Enamic (VE), and Vita Suprinity (VS) and were divided into laboratory and chairside polishing. Reflection wavelength spectra, CIE D65 standard illuminant, 2 ° standard observer, SCI, UV included, SAV aperture, 6 mm diameter, were recorded at 10 nm sensitivity against white and black calibration tiles using a benchtop spectrophotometer. Subsequently, they were converted into CIEDE 2000 TP00. After baseline measurements (T0), the specimens were divided as follows (n = 8): staining in coffee (C) and wine (W), for 60 (T1) and 120 hours (T2), and accelerated artificial aging (A). Artificial aging (ISO 4892-2 standard) was performed in two cycles of 150 KJ/m2, for T1 and T2, respectively. TP measurements were repeated at T1 and T2. Data of TP00 retention were submitted to analysis of variance and Fisher’s PLSD multiple comparison test (α=0.05).ResultsFisher’s PLSD critical differences among materials, time intervals and staining/aging were 0.16, 0.11 and 0.11, respectively. SH showed the highest TP00 followed by LU > CS > IE = VS > VE. For all time intervals, the lowest TP00 retention was observed with C. W, and A presented similar values.ConclusionsTranslucency Parameter was a time and staining/aging-dependent material. In majority of cases, it decreased upon staining/aging.

Orthodontic-assisted one step- no prep technique: A straightforward and minimally-invasive approach for localized tooth wear treatment using polymer-infiltrated ceramic network CAD-CAM prostheses.

To introduce a minimally invasive and simple ortho-pros approach for localized tooth wear treatment. Four patients with localized anterior and/or posterior tooth wear were treated. Occlusal analyses were performed, and localized wax-up or digital setup were designed based on estimated tissue loss. No-prep anterior and posterior partial-coverage polymer-infiltrated ceramic network (PICN, Vita Enamic) restorations (eg, palatal and occlusal veneers) were computer-aided designed and manufactured (CAD-CAM), tried in, and bonded in supraocclusion, creating a posterior open bite. Then, brief partial (three patients) or global (one patient, for anterior teeth alignment request) orthodontic treatment was performed to extrude the posterior teeth and re-establish posterior occlusal contacts. The orthodontic treatment duration was ~2 months for extrusion. Direct composites were performed to mask the labial finish line of palatal veneers. Clinical results were successful after a follow-up of 15, 21, 23, and 47 months, with 100% success rate of PICN anterior restorations and some minor chippings of borders of thin (0.2 mm) posterior occlusal veneers. Patient-reported outcomes were positive. Orthodontic-assisted one step-no prep technique is an advantageous and straightforward evolution of the Dahl concept. PICNs exhibit several advantages in this interdisciplinary approach. New hybrid-ceramic CAD-CAM materials and a collaborative interdisciplinary approach support the evolution of the Dahl concept for conservative treatment of worn dentitions. The orthodontic-assisted one step-no prep technique is predictable, efficient, and well tolerated by patients and conserves tooth structure.

Radiographic evaluation of crystal bone level of immediate loaded implant restored with two different CAD-CAM materials

Purpose This study was conducted to radiographically evaluate the effect of two different superstructure CAD/CAM fabricated materials, on crestal bone loss around immediately loaded implant. Materials and Methods A total of twelve healthy patients having mandibular bilateral missing first molars with acceptable bone volume were selected based on specific inclusion and exclusion criteria, each patient received a CAD/CAM monolithic zirconia, in one site, while the other site received a CAD/CAM Enamic superstructure, in 48 hours after implant insertion. Implants and abutments were examined for stability, gingival and periodontal health prior to crown cementation. Radiographic evaluation was done immediately at the time of crown cementation then at 6 and 12 months. Results Marginal bone loss was measured at two points, the most buccal crestal bone, and the most lingual crestal bone. Radiographic results showed no significant difference regarding mean MBL between Zirconia and Enamic on 6 and 12 months. Conclusion Immediate loading of a single mandibular molar implant with the final restoration seem to be a reliable technique when certain parameters are respected. Type of implant superstructure material has no significant influence on the bone supporting the implant within the time period of this study.

Comparison of strains for new generation CAD-CAM implant-supported crowns under loading.

The behavior of implant-crowns fabricated from recently introduced CAD-CAM zirconia-reinforced lithium silicate ceramic (ZLS) or a hybrid ceramic containing resin-reinforced glass network (HC) for strains around the implant platform is not well-known. A force absorption capacity of the latter has been claimed by the manufacturer. The aim of this study was to measure and compare recently introduced ZLS and HC with commonly used CAD-CAM implant crown materials for strain distribution around the implant platform. Four implants (Legacy 1; Implant Direct) were placed into a resin block. Zirconia abutments (Straight contoured stock abutment; Implant Direct) were torqued into the implant fixtures to support crowns that were milled from a virtual design using four different CAD-CAM materials (Vita Suprinity PC (ZLS), Vita Enamix (HC), IPS Emax, ZirCAD Zirkonzahn) (N = 20). The crowns were cemented with a resin cement, loaded and strain values were recorded. Three-dimensional digital image correlation (3D-DIC) was used to measure compressive and tensile strains around the implant platforms. The tensile and compressive strains were recorded for each test and first analyzed for equality of variance using Levene's test, and further tested using a 2-way ANOVA repeated measures analysis of variance (α = .05). The data analysis showed no statistically significant effect of crown material on the generated strains (P > .05). Compressive strains were significantly higher than the tensile strains (P < .05). One of the HC crowns fractured during loading. Strains generated around implant platform when new generation CAD-CAM crown materials were used was similar to strains observed when CAD-CAM zirconia and lithium disilicate crowns were used. New generation crown materials did not have a significant load absorption effect to change or minimize the strains generated around the implant platform.

Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Veneer Materials and Shades of Resin Cements

Abstract This study aimed to assess the masking potential of different CAD-CAM veneer restorations to restore tetracycline-stained teeth. One-hundred-eight CAD-CAM ceramic discs, shade 1M1, with high (HT) and low (LT) translucencies and 1mm and 0.7mm thicknesses were prepared from three CAD-CAM materials (IPS-e.max-CAD (EMC), VITA Enamic (VE) and Vita Suprinity (VS)). Resin cements, shades A1, white opaque (WO) and translucent (T), were used for cementation against a dark base. Color differences (ΔE*) between the restorations (veneer/resin cement/dark base) and a standard 1M1 shade-guide-tab were calculated. Mann-Whitney-U and Wilcoxon-signed-rank tests; and one-way ANOVA, Kruskal-Wallis and Bonferroni-post-hoc tests were used to compare between two and three groups respectively (P ≤0.05). Groups EMC-LT-0.7-T, VE-LT-1-A1 and VE-LT-1-T rendered restorations with ΔE* below the perceptibility threshold (<1.74), while EMC-LT-0.7-A1 and all LT-0.7mm VE restorations were within the acceptability threshold (<3.48). VS had significantly higher (ΔE*) compared to of EMC and VE materials. Ceramic thicknesses had no significant effect on (ΔE*), while the effect of translucency level of the ceramics and the shade of resin cement was significant. It was concluded that low translucency ceramic veneers can better mask darkly stained teeth, irrespective of their thicknesses, with resin cements shades affecting the color of the final restorations.

Adhesion, Mechanical Properties, and Microstructure of Resin-matrix CAD-CAM Ceramics.

To investigate the effects of 1-year water storage and surface treatments on shear bond strength (SBS) of two composite cements bonded to resin matrix CAD-CAM ceramics (RMCs) and on the mechanical properties of RMCs. Three types of RMCs were tested: 1. polymer-infiltrated hybrid ceramic (PIHC, Enamic, VITA Zahnfabrik); 2. resin nanoceramic (RNC, Lava Ultimate, 3M Oral Care); and 3. flexible hybrid ceramic (FHC, Cerasmart, GC). One indirect laboratory composite (ILC, Epricord, Kuraray Noritake) was used as control. For each material, 60 plates (14 x 7 x 1 mm) were prepared for the SBS test and submitted to three different surface treatments: following manufacturer's instructions, non-thermal atmospheric plasma application (30 s), and plasma + bonding agent. Two composite cements were tested: RelyX Ultimate (3M Oral Care) and Panavia V5 (Kurarary Noritake). Two resin cylinders (1.5 mm diameter x 1.5 mm height) were bonded to each plate (n = 10), with one tested after 24-h storage in distilled water and the other after 1 year of storage in distilled water. Twenty rectangular bars (12 x 2 x 1 mm) of each indirect material were prepared and submitted to the 3-point flexural test after 24-h or 1-year water storage to determine the elastic modulus (EM) and flexural strength (FS) (n = 10). Fractured samples were also examined with SEM and energy dispersive x-ray spectroscopy (EDS). SBS data were analyzed by four-way ANOVA, and EM and FS data by two-way ANOVA, followed by Tukey's post-hoc test (α = 0.05). Groups treated in accordance with manufacturer's instructions exhibited higher SBS than did plasma and plasma + bonding agent groups for all indirect materials, composite cements, and storage periods tested. In general, RelyX Ultimate displayed higher mean SBS than did Panavia V5, except for some groups of ILC where manufacturer's instructions were followed. After 1-year storage in water, all groups exhibited a significant reduction in SBS, except for some groups that following manufacturer's instructions. ILC showed the lowest values of EM and FS. Among the CAD-CAM materials, FHC exhibited the lowest EM and highest FS means, while PIHC possessed the highest EM and lowest FS means for both storage periods. In general, following the respective manufacturer's instructions yielded the best bond strength results. For most materials, 1-year water storage decreased bond strength of composite cements to RMCs, as well as their FS, while increasing their EM. Microstructure and composition influenced the mechanical properties studied.

Clinical performance of new CAD CAM materials for inlay onlay restorations – Three‐year results

Clinical performance of new CAD CAM materials for inlay onlay restorations – Three‐year results

Comparison of Bond Strength of Monolithic CAD-CAM Materials to Resin Cement Using Different Surface Treatment Methods

Objective: To compare the bond strength of monolithic CAD-CAM materials to resin cement using different surface treatment methods. Materials and Methods: Lithium disilicate glass ceramic (IPS e-max CAD), zirconia-reinforced lithium silicate ceramic (Vita Suprinity), resin nanoceramic (Lava Ultimate), and hybrid ceramic (Vita Enamic) were used. Five groups of CAD-CAM blocks were treated as follows: control (C), HF etching (HF), HF etching + silanization (HF + S), sandblasting (SB), and sandblasting + silanization (SB + S). After surface treatments, SEM analyses were conducted. Specimens were cemented with self-adhesive resin cement (Theracem) and stored in distilled water at 37°C for 24 h. Shear bond strength (SBS) was measured, and failure types were categorized. Results were analyzed using two-way ANOVA and the post-hoc Tukey test. Results: Statistical analysis revealed significant differences between SBS values obtained for different surface treatments and CAD-CAM block types ( P &lt; .001). Among the CAD-CAM materials, the highest SBS was reported in the HF + S group for Vita Enamic. Although IPS e.max CAD, Vita Suprinity, and Vita Enamic showed higher bond strength when treated with HF + S, Lava Ultimate has the highest bond strength value when treated with SB + S. Conclusions: The bond strength of CAD-CAM materials was influenced by surface treatment. Additionally, silanization significantly improved the bond strength of all materials except Lava Ultimate.

Effect of UV aging on translucency of currently used esthetic CAD-CAM materials.

To evaluate the relative translucency parameter (RTP) values of computer-aided design (CAD)-computer-aided manufacturing (CAM) materials after UV aging. 70 specimens (n = 10) of Bruxzir Anterior (BA); E.max Cad (EC); Lava Ultimate (LU); Cerasmart (CE); Vita Enamic (VE); Vita Suprinity (VS); Vita Mark II (VM) were prepared (1 mm ± 0.01 mm). Color measurements were performed using a spectrofotometer (VITA Easyshade). RTP values of the specimens before (RTP1 ) and after UV aging (RTP2 ) were evaluated. Statistical analyses were done with repeated measurements of two-way-ANOVA with Bonferroni test (P < 0.05). Evaluating RTP1 and RTP2 values; significant differences were found (P < 0.05). There were no significant difference between the RTP1 values of CE and VS (P = 0.779); EC and VM (P = 0.952); VM and LU (P = 0.995); EP and LU (P = 0.653). Evaluating RTP2 values; VE and BA were found significantly different from the others (P < 0.05). For all evaluated groups TP values decreased after UV aging (P < 0.05). The most RTP reduction was observed for LU; while VM and EC were less affected. Glass ceramic VE showed the highest RTP and zirconia-based BA was the most opaque restorative CAD-CAM material. UV aging caused the CAD-CAM materials get more opaque. In cases where translucency is needed chosing VE would give better esthetic results; while zirconia-based BA should be used if more opaque restoration is needed. Clinicians should be aware of that restorations get more opaque after usage.

Evaluation of shear bond strength of zirconia-based monolithic CAD-CAM materials to resin cement after different surface treatments.

To compare the shear bond strength of resin cement to zirconia-based monolithic CAD-CAM materials subjected to different surface treatments. 2 brands of monolithic zirconia blocks (Vita YZ HT, Sirona inCoris TZI), yttrium-stabilized tetragonal zirconia (IPS e.max ZirCAD) and zirconia-reinforced lithium silicate ceramic (Vita Suprinity) were divided into six groups according to the surface treatment received: no treatment (control), HF acid etching, sandblasting, sandblasting + Er:YAG laser irradiation, Er:YAG laser irradiation and CoJet. Composite resin cylinders were bonded to blocks with self-adhesive resin cement (Theracem). Shear bond strength was evaluated after thermocyling. Failure modes were examined using SEM. Data was analyzed statistically by using 2-way ANOVA and post-hoc Tukey's test (P < 0,05). The bond strength was significantly affected by the surface treatment and the type of CAD-CAM blocks (P < 0,001). Surface treatment with CoJet revealed significantly higher bond strength compared to sandblasting in Y-TZP and monolithic zirconia specimens. Monolithic zirconia blocks showed higher bond strength values compared to Y-TZP zirconia block in sandblasting and CoJet groups. HF acid etching is more effective than sandblasting and CoJet for Vita Suprinity.

Influence of Pretreatment Methods on the Adhesion of Composite and Polymer Infiltrated Ceramic CAD-CAM Blocks.

To assess the effect of different surface pretreatments on the shear bond strength of resin luting material on CAD-CAM composite resins and a polymer-infiltrated ceramic network (PICN). CAD-CAM materials (Brilliant Crios, Cerasmart, Lava Ultimate, VITA Enamic) were subjected to the following pretreatments: no pretreatment; grit blasting; grit blasting + silane; HF etching + silane; tribochemical silica coating + silane; manufacturers' specifications; manufacturers' specifications + silane; manufacturers' specifications using only the manufacturers' products including their recommended luting materials (DuoCem, G-Cem LinkForce, RelyX Ultimate, RelyX Unicem 2). Specimens were luted with resin luting material according to the Swiss shear test design. After six months of water storage, shear bond tests were performed. Data were analyzed with multiple linear regression models and nested models (α = 0.05). Low bond strengths were obtained without pretreatment (Brilliant Crios 3.01 ± 0.54 MPa, Cerasmart 2.66 ± 0.47 MPa, Lava Ultimate 1.76 ± 0.26 MPa, VITA Enamic 2.83 ± 0.63 MPa). Grit blasting achieved high bond strengths across all materials (Brilliant Crios 5.17 ± 0.77 MPa, Cerasmart 4.27 ± 0.50 MPa, Lava Ultimate 3.98 ± 0.54 MPa, VITA Enamic 4.97 ± 0.90 MPa). Silane application tended to decrease bond strengths on CAD-CAM composite resins. Following the manufacturers' specifications and using their recommended materials achieved the highest bond strengths for all materials except Cerasmart (Brilliant Crios 5.75 ± 0.91 MPa, Cerasmart 2.82 ± 0.28 MPa, Lava Ultimate 6.63 ± 0.97 MPa, VITA Enamic 7.09 ± 0.77 MPa). Grit blasting and the application of a suitable material primer is a useful pretreatment for the bonding of CAD-CAM composite resins. Silane application on CAD-CAM composite resins may entail drawbacks, possibly owing to the scarcity of silanizable fillers.

The evaluation of the surface micro-hardness values in different depth of resin blocks

Objective: Computer-aided design and manufacturing technology has shown great improvement in dentistry since the 1980s. This technology is based on a one-stage restoration using prefabricated blocks. Two main types of materials are used during CAD / CAM indirect restorations: glass-ceramic / ceramic and resin composite. CAD / CAM resin blocks are polymerized under high temperature and pressure. Polymerization depth affects the surface hardness of composite resins. When preparing a restoration, different depth layers of the resin block are used. The aim of this study is to show that adequate polymerization is achieved in each layer of the resin blocks and that the hardness of each layer is the same. Two composite resin block materials and one hybrid resin block material were included in this study. Material and method: The CAD/CAM block materials evaluated in this study were Cerasmart, Lava and Vita Enamic Square specimens (n=5/material) of approximate dimensions 10×10×2 mm blocks were sectioned (5 slices/block) from commercially available CAD-CAM materials using a diamond saw (exakt 300 cl Apparatebau, Norderstedt, Germany) with water cooling. All specimens were abraded followed by 500,1200,2500 grid using SiC abrasive paper (exakt 400 cs Apparatebau, , Norderstedt, Germany). After storage in distilled water at 37 °C for 24 hours the Knoop hardness test was performed using a hardness testing machine (Buehler MMT 3 digital micro hardness tester, Lake Bluff, IL, USA) using a load of 500 gf and a loading time of 10s. Results: The material with the highest hardness number was Vita Enamic block, whereas the lowest numbered group was the Cerasmart. The rank order of surface hardness was as follows: Vita Enamic&amp;gt; Lava Ultimate &amp;gt;Cerasmart. Conclusion: The hardness measurements of the layers of blocks were similar.

Effect of Different Surface Treatment Methods on Micro-Shear Bond Strength of CAD-CAM Restorative Materials to Resin Cement.

This study aimed to investigate the micro-shear bond strength (μSBS) of surface treated CAD-CAM materials to resin cement. The specimens obtained from IPS e.max CAD, Lava Ultimate, Cerasmart and Vita Enamic were divided according to the surface treatment method applied as: no treatment, 3W and 2W Er, Cr:YSGG laser irradiation, sandblasting and 5% hydrofluoric acid (HF) application. Then, μSBS and field emission-scanning electron microscope analysis were performed. Data were analyzed using the Mann Whitney U and the Kruskal Wallis tests. For all materials, the highest μSBS values were demonstrated in HF acid applied groups. Regarding the μSBS values of IPS e.max CAD, no significant differences were found among control, 2W Er, Cr:YSGG laser and sandblasting groups (p > 0.05). For Cerasmart and Lava Ultimate; 2W Er, Cr:YSGG laser treated group showed significantly lowest μSBS values while there was no significant difference among control, 3W Er, Cr:YSGG and sandblasting groups. HF applied Lava Ultimate and IPS e.max CAD groups exhibited the highest μSBS values among all the groups. For Vita Enamic; significantly lowest μSBS values were obtained in sandblasting group, whereas there was no significant difference among control, 3W Er, Cr:YSGG and 2W Er, Cr:YSGG groups (p > 0.05). The FE-SEM images of all CAD-CAM materials submitted to surface treatment revealed an increase in surface alterations compared to control groups. It can be concluded that prior to bonding 5% HF acid treatment is the best surface treatment method regarding the bond strength for all CAD-CAM restorative materials. Er, Cr:YSGG laser application with energy level of 3W can be recommended for IPS e.max CAD.

Custom CAD/CAM implants for complex craniofacial reconstruction in children: Our experience based on 136 cases✰

BackgroundCAD-CAM patient-specific implants offer cerebral protection and improved facial balance without the disadvantages of autologous bone grafting such as donor site morbidity and unpredictable resorption. Several alloplastic materials are available, but titanium, polymethylmethacrylate (PMMA), and polyetheretherketone (PEEK) are the current popular choices. We reviewed our experience of applying different alloplastic CAD-CAM materials in the reconstruction of complex pediatric craniofacial deformities. MethodsA retrospective review was performed of all pediatric patients who underwent a complex inlay or onlay implant craniofacial reconstruction using CAD-CAM PEEK, PMMA, or titanium implants at a single institution. Demographics, cost, operative time, complications, and outcomes were assessed. ResultsBetween 2003 and 2014, 136 patients (69 male; 67 female; mean age 11.5 years (3–22 years); mean follow-up 30 months) had custom patient-specific craniofacial reconstruction with PEEK (n = 72), PMMA (n = 42), and titanium (n = 22) implants (inlay = 93; onlay = 43). Indications included congenital anomalies (26.5%), decompressive craniectomies (25.0%), craniofacial syndromes (25.7%), tumor defects (14.0%), and post-trauma (6.6%). Implant cost varied significantly for PEEK ($7703 CAD) and PMMA ($8328 CAD) compared with that for titanium ($11,980 CAD) (p < 0.0005). Six patients (4.4%) required surgery due to infection consisting of irrigation and antibiotic administration with successful implant salvage in three patients. All infections occurred in the PEEK group. Five patients (3.7%) ultimately had implants removed due to infection (n = 3), late exposure (titanium; n = 1), or late fracture (PMMA; n = 1). ConclusionsCAD-CAM alloplast reconstruction in the management of complex pediatric craniofacial deformities is effective although expensive. Implant infection does not always require explantation. A reconstruction algorithm is presented.

Wear resistance and abrasiveness of CAD-CAM monolithic materials

Statement of problemComputer-aided design and computer-aided manufacturing (CAD-CAM) restorations are in contact with the antagonist tooth, either a natural tooth or a restoration. Therefore, clinicians should be aware of the wear resistance of CAD-CAM materials and the wear behavior of the antagonist. PurposeThe purpose of this in vitro study was to evaluate the wear resistance and abrasiveness of CAD-CAM materials. Material and methodsIn a 2-body wear test, the materials IPS e.max CAD (Ivoclar Vivadent AG), Vita Suprinity (Vita Zahnfabrik), Lava Ultimate (3M ESPE), Vita Enamic (Vita Zahnfabrik), and Lava Plus (3M ESPE) acted as abraders and, together with bovine enamel, also as antagonists. Each antagonist wheel ran against each abrader wheel for 200000 cycles, with a spring force of 15 N, and at a rotational speed of 1 Hz in distilled water. The wear rate was determined with a surface profilometer. The surfaces were observed with scanning electron microscopy, and their hardness, coefficient of friction, and roughness were evaluated. ResultsLava Plus and IPS e.max CAD exhibited the highest potential for wear of Lava Ultimate. These 2 materials, together with Vita Suprinity, provided the highest wear of enamel and Vita Enamic. Vita Suprinity and IPS e.max CAD had higher wear than Lava Plus, and the inverse was also true. Vita Enamic and Lava Ultimate were among the materials that caused the lowest wear of enamel and all other evaluated materials. Scanning electron microscopy images revealed that except for Lava Ultimate, all other materials damaged enamel, in which Vita Suprinity and IPS e.max CAD were more aggressive when sliding against the materials. Lava Plus had the greatest hardness, followed by Vita Suprinity and IPS e.max CAD, Vita Enamic, and then Lava Ultimate. The coefficient of friction varied from 0.42 to 0.53. The Vita Enamic and Lava Ultimate showed the highest surface roughness. ConclusionsThe nanofilled composite resin and polymer-infiltrated ceramic were more antagonist-friendly (whether enamel or CAD-CAM material) than glass-ceramics and zirconia. Care should be taken when selecting the material that will contact mainly with glass-ceramics. Hardness should also be considered when selecting a material.

A Functionally Graded PICN Material for Biomimetic CAD-CAM Blocks

The objective of this study was to introduce a functionally graded (FG) polymer-infiltrated ceramic network (PICN) block, characterized by a gradient of mechanical properties, as a biomimetic material for computer-aided design and manufacturing (CAD-CAM) prostheses. FG-PICN blocks were manufactured from a slurry of glass-ceramic powder, which was subsequently centrifuged and sintered. The ceramic network was infiltrated with urethane dimethacrylate and polymerized under high temperature-pressure. Blocks were sectioned into 9 layers, and each layer was subsequently cut into 3 samples. Samples were loaded into a 3-point bending device and tested for flexural strength, flexural load energy, and flexural modulus. The volume percentage of glass-ceramic, hardness, and brittleness index were also measured and scanning electron microscopy (SEM) observations were performed. Katana translucent zirconia (HT-ZIR) and e.max-CAD (EMX) were tested for comparison. Flexural strength, flexural load energy, and Weibull modulus of FG-PICN were shown to increase from the first (enamel-like zone) to the ninth layer (dentin-like zone), while, on the contrary, flexural modulus, hardness, brittleness index, and ceramic volume percentage decreased. SEM characterization highlighted a higher porosity in layer 9 than in layer 1. Flexural strength of the dentin-like zone (372.7 ± 27.8 MPa) was similar to EMX and lower than HT-ZIR. Flexural modulus was shown to vary from 41.9 ± 5.1 to 28.6 ± 2.0 GPa from surface to depth. Flexural load energy in the dentin-like zone (27.1 ± 4.9 mJ) was significantly superior to EMX and HT-ZIR. Hardness gradient was shown to be close to tooth tissues. This work introduces FG-PICN blocks, with a gradient of mechanical and optical properties through the entire thickness of the block designed to mimic dental tissues. FG-PICN demonstrated a favorable gradient of flexural strength, elastic modulus, and, most of all, flexural load energy and hardness compared to other CAD-CAM materials, which can promote the biomechanical behavior of single-unit restorations on teeth and implants.