Routine practice data of three cancer entities: Comparison among cancer registry and health insurance data.

INTRODUCTION: Claims data and cancer registry data are valuable secondary data sources for addressing health service research questions. This study provides a thorough insight into the comparability of data from health insurance companies and cancer registries in Germany regarding breast, prostate, and lung cancer patients and their treatment. METHODS: For this study claims data of the InGef database and data of the Cancer Registry of Rhineland-Palatinate were used to identify patients living in Rhineland-Palatinate with an incident breast, prostate, or lung cancer diagnosis between Jan. 1, 2018 and Dec. 31, 2019. Both datasets were compared for patient and tumour characteristics as well as treatment strategy. For the descriptive analysis of tumour localisation and treatment all patients were followed up for a maximum of two years. RESULTS: A total of 1,470 incident cancer cases were identified in the InGef database and 1,694 in the Cancer Registry. Data on sex, age, and tumour localisation matched well for all cancer entities in the cohorts. Data for early UICC stages I+II varied between the cohorts for prostate cancer (84% InGef, 66% Cancer Registry) and lung cancer (29% InGef, 20% Cancer Registry). Larger deviations were found for antihormonal treatment (breast 54% vs. 44%, prostate 32% vs. 18%). Significant differences were found for surgery (breast and lung) and radiation (breast and prostate), respectively. DISCUSSION: Age at diagnosis, tumour localisation, and treatment for breast cancer was well documented in both databases. Tumour-specific deviations were observed for tumour localisations (lung cancer), UICC stage (prostate and lung cancer) and treatment options. CONCLUSION: Both databases show very good completeness across cancer entities, but at the same time have minor limitations where they could readily complement each other. Individual linkage of claims and registry data could be an important step to improve oncological studies with routine practice data and to overcome the limitations identified.

Mutant SOD1 aggregates formed in vitro and in cultured cells are polymorphic and differ from those arising in the CNS.

Mutations in the human Superoxide dismutase 1 (hSOD1) gene are well-established cause of the motor neuron disease ALS. Patients and transgenic (Tg) ALS model mice carrying mutant variants develop hSOD1 aggregates in the CNS. We have identified two hSOD1 aggregate strains, which both transmit spreading template-directed aggregation and premature fatal paralysis when inoculated into adult transgenic mice. This prion-like spread of aggregation could be a primary disease mechanism in SOD1-induced ALS. Human SOD1 aggregation has been studied extensively both in cultured cells and under various conditions in vitro. To determine how the structure of aggregates formed in these model systems related to disease-associated aggregates in the CNS, we used a binary epitope-mapping assay to examine aggregates of hSOD1 variants G93A, G85R, A4V, D90A, and G127X formed in vitro, in four different cell lines and in the CNS of Tg mice. We found considerable variability between replicate sets of in vitro-generated aggregates. In contrast, there was a high similarity between replicates of a given hSOD1 mutant in a given cell line, but pronounced variations between different hSOD1 mutants and different cell lines in both structures and amounts of aggregates formed. The aggregates formed in vitro or in cultured cells did not replicate the aggregate strains that arise in the CNS. Our findings suggest that the distinct aggregate morphologies in the CNS could result from a micro-environment with stringent quality control combined with second-order selection by spreading ability. Explorations of pathogenesis and development of therapeutics should be conducted in models that replicate aggregate structures forming in the CNS.

Effect of crown height on the screw joint stability of zirconia screw-retained crowns.

STATEMENT OF PROBLEM: Medium- to long-term data for the performance of zirconia crowns with titanium (Ti) bases are sparse, particularly when the crown height space and occlusal loads are high. PURPOSE: The purpose of this in vitro study was to assess the effect of the height of zirconia screw-retained implant crowns with a Ti base on the screw joint stability after cyclic loading. A secondary aim was to investigate the survival of zirconia crowns of different heights after cyclic loading. MATERIAL AND METHODS: Twenty-one internal connection implants were secured between fiberglass-reinforced epoxy resin sleeves. Mandibular first molar monolithic zirconia crowns with 3 different heights (6 mm, 10 mm, and 14 mm) were milled and bonded to the Ti bases (n=7). The screws were tightened to 30 Ncm, and a 30-degree 120-N cyclic load was applied to the crowns at 2 Hz for 5 million cycles. After 5 million cycles, the crowns were evaluated for stability, and the same protocol was repeated for 275-N and 435-N loads for 5 million cycles each. After loading, the detorque values were recorded. Failure was characterized based on whether the crown, screw, and/or implant fracture was observed. The detorque values were analyzed by using a 1-way-ANOVA with the restricted maximum likelihood estimation. The percentage of torque loss was calculated. The LIFETEST procedure was used to analyze the survival probability of the groups (α=.05). RESULTS: The effect of crown height on the detorque values of screws was not found to be statistically significant (P>.05). The mean detorque value for 6-mm crowns was 23.5 Ncm, 24.4 Ncm for 10-mm crowns, and 22.1 Ncm for 14-mm crowns. A significant effect of crown height was found on the survival (P=.006), and the time-to-failure survival of 14-mm crowns was significantly lower than the survival of 6 mm and 10 mm crowns (P=.020), where no failures were observed. Four 14-mm crowns failed between the 1 and 2 million cycles after the loads were increased to 435 N. The failure modes were the same for all the crowns, implants, and screws fractured. CONCLUSIONS: When the tested internal connection implant was used, the crown height did not affect the detorque values, and 14-mm crowns performed similarly to the shorter crowns in terms of torque loss after cyclic loading. However, survival of the 14-mm crown-implant complex was lower, resulting in screw and implant fractures.

Effect of Crown Height on the Screw Stability of Titanium Screw-Retained Crowns.

PURPOSE: The aim of this in vitro study was to evaluate the effect of crown height on the screw stability of screw-retained titanium implant crowns subjected to cyclic loading conditions. MATERIALS AND METHODS: Twenty-one implants with internal hex connections were placed in epoxy resin holders. Mandibular first molar screw-retained titanium implant crowns with UCLA type, crown-abutment connections were CAD/CAM fabricated. Seven crowns of 3 different heights (6 mm, 10 mm, and 14 mm) were made. The crowns were seated onto the implants and screws were tightened to 30 Ncm. The implants were clamped into holders and stepwise cyclic loads were applied to the occlusal surface at 30-degree angles to the long axes of the crowns. The detorque values were measured after each 5 million cycles. Before increasing the applied load, the crowns were secured with new screws and tightened to 30 Ncm. Failure times, survival estimates and detorque values were then analyzed. (alpha = 0.05). RESULTS: Crown height did not significantly affect detorque values. However, five 14-mm crowns failed with varying fractures during the 475 N loading condition. Overall, a significantly lower survival for 14 mm crowns was found compared to 6 mm and 10 mm crowns (p = 0.004). CONCLUSIONS: Crown heights of one-piece screw-retained titanium implant crowns did not significantly affect detorque values. Screw fracture, however, was greater for crown height of 14 mm than those of 6 mm and 10 mm.

Weighted mandibular complete denture fabricated by using selective laser melting: A clinical report.

The rehabilitation of patients with severely resorbed mandibular ridges can be a clinical challenge when rehabilitation with endosteal implants is not the elected treatment. Historically, weighted mandibular complete dentures have been used successfully to manage patients with severely resorbed ridges, and the weight of their cast metal has been calculated by using the weight of the wax and the density of the alloy. This clinical report presents the management of an 87-year-old woman with a severely resorbed mandibular ridge by using a weighted mandibular complete denture fabricated by using selective laser melting (SLM) technology in which the weight of the metal base was calculated by using the volume of the digital file used for manufacture.

Charge Engineering Reveals the Roles of Ionizable Side Chains in Electrospray Ionization Mass Spectrometry.

In solution, the charge of a protein is intricately linked to its stability, but electrospray ionization distorts this connection, potentially limiting the ability of native mass spectrometry to inform about protein structure and dynamics. How the behavior of intact proteins in the gas phase depends on the presence and distribution of ionizable surface residues has been difficult to answer because multiple chargeable sites are present in virtually all proteins. Turning to protein engineering, we show that ionizable side chains are completely dispensable for charging under native conditions, but if present, they are preferential protonation sites. The absence of ionizable side chains results in identical charge state distributions under native-like and denaturing conditions, while coexisting conformers can be distinguished using ion mobility separation. An excess of ionizable side chains, on the other hand, effectively modulates protein ion stability. In fact, moving a single ionizable group can dramatically alter the gas-phase conformation of a protein ion. We conclude that although the sum of the charges is governed solely by Coulombic terms, their locations affect the stability of the protein in the gas phase.

Repeated exposure to transient obstructive sleep apnea-related conditions causes an atrial fibrillation substrate in a chronic rat model.

BACKGROUND: High night-to-night variability in obstructive sleep apnea (OSA) is associated with atrial fibrillation (AF). Obstructive apneas are characterized by intermittent deoxygenation-reoxygenation and intrathoracic pressure swings during ineffective inspiration against occluded upper airways. OBJECTIVE: We elucidated the effect of repeated exposure to transient OSA conditions simulated by intermittent negative upper airway pressure (INAP) on the development of an AF substrate. METHODS: INAP (48 events/4 h; apnea-hypopnea index 12 events/h) was applied in sedated spontaneously breathing rats (2% isoflurane) to simulate mild-to-moderate OSA. Rats without INAP served as a control group (CTR). In an acute test series (ATS), rats were either killed immediately (n = 9 per group) or after 24 hours of recovery (ATS-REC: n = 5 per group). To simulate high night-to-night variability in OSA, INAP applications (n = 10; 24 events/4 h; apnea-hypopnea index 6/h) were repeated every second day for 3 weeks in a chronic test series (CTS). RESULTS: INAP increased atrial oxidative stress acutely, represented in decreases of reduced to oxidized glutathione ratio (ATS: INAP: 0.33 ± 0.05 vs CTR: 1 ± 0.26; P = .016), which was reversible after 24 hours (ATS-REC: INAP vs CTR; P = .274). Although atrial oxidative stress did not accumulate in the CTS, atrial histological analysis revealed increased cardiomyocyte diameters, reduced connexin 43 expression, and increased interstitial fibrosis formation (CTS: INAP 7.0% ± 0.5% vs CTR 5.1% ± 0.3%; P = .013), which were associated with longer inducible AF episodes (CTS: INAP: 11.65 ± 4.43 seconds vs CTR: 0.7 ± 0.33 seconds; P = .033). CONCLUSION: Acute simulation of OSA was associated with reversible atrial oxidative stress. Cumulative exposure to these transient OSA-related conditions resulted in AF substrates and was associated with increased AF susceptibility. Mild-to-moderate OSA with high night-to-night variability may deserve intensive management to prevent atrial substrate development.

Publisher Correction: In vitro investigation of chemical properties and biocompatibility of neurovascular braided implants.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cathepsin A contributes to left ventricular remodeling by degrading extracellular superoxide dismutase in mice.

In the heart, the serine carboxypeptidase cathepsin A (CatA) is distributed between lysosomes and the extracellular matrix (ECM). CatA-mediated degradation of extracellular peptides may contribute to ECM remodeling and left ventricular (LV) dysfunction. Here, we aimed to evaluate the effects of CatA overexpression on LV remodeling. A proteomic analysis of the secretome of adult mouse cardiac fibroblasts upon digestion by CatA identified the extracellular antioxidant enzyme superoxide dismutase (EC-SOD) as a novel substrate of CatA, which decreased EC-SOD abundance 5-fold. In vitro, both cardiomyocytes and cardiac fibroblasts expressed and secreted CatA protein, and only cardiac fibroblasts expressed and secreted EC-SOD protein. Cardiomyocyte-specific CatA overexpression and increased CatA activity in the LV of transgenic mice (CatA-TG) reduced EC-SOD protein levels by 43%. Loss of EC-SOD-mediated antioxidative activity resulted in significant accumulation of superoxide radicals (WT, 4.54 µmol/mg tissue/min; CatA-TG, 8.62 µmol/mg tissue/min), increased inflammation, myocyte hypertrophy (WT, 19.8 µm; CatA-TG, 21.9 µm), cellular apoptosis, and elevated mRNA expression of hypertrophy-related and profibrotic marker genes, without affecting intracellular detoxifying proteins. In CatA-TG mice, LV interstitial fibrosis formation was enhanced by 19%, and the type I/type III collagen ratio was shifted toward higher abundance of collagen I fibers. Cardiac remodeling in CatA-TG was accompanied by an increased LV weight/body weight ratio and LV end diastolic volume (WT, 50.8 µl; CatA-TG, 61.9 µl). In conclusion, CatA-mediated EC-SOD reduction in the heart contributes to increased oxidative stress, myocyte hypertrophy, ECM remodeling, and inflammation, implicating CatA as a potential therapeutic target to prevent ventricular remodeling.

The biogenesis of CLEL peptides involves several processing events in consecutive compartments of the secretory pathway.

Post-translationally modified peptides are involved in many aspects of plant growth and development. The maturation of these peptides from their larger precursors is still poorly understood. We show here that the biogenesis of CLEL6 and CLEL9 peptides in Arabidopsis thaliana requires a series of processing events in consecutive compartments of the secretory pathway. Following cleavage of the signal peptide upon entry into the endoplasmic reticulum (ER), the peptide precursors are processed in the cis-Golgi by the subtilase SBT6.1. SBT6.1-mediated cleavage within the variable domain allows for continued passage of the partially processed precursors through the secretory pathway, and for subsequent post-translational modifications including tyrosine sulfation and proline hydroxylation within, and proteolytic maturation after exit from the Golgi. Activation by subtilases including SBT3.8 in post-Golgi compartments depends on the N-terminal aspartate of the mature peptides. Our work highlights the complexity of post-translational precursor maturation allowing for stringent control of peptide biogenesis.

Long-term outcome of adhesive fragment reattachment in crown-root fractured teeth.

BACKGROUND/AIMS: Adhesive fragment reattachment (AFR) is one treatment option for crown-root fractured teeth. However, there are no studies investigating the long-term outcome of this approach. The aim of this retrospective study was to evaluate the long-term outcome of AFR and periodontal health in crown-root fractured teeth by assessing complications and periodontal status. MATERIALS AND METHODS: Data regarding 41 patients with 51 traumatized teeth (TT) were included. Periodontal health was assessed by recording the pocket probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BoP), gingival index (GI), and plaque index (PI) in the TT and in one unaffected control tooth (CT). Complications were classified as "restorative," "endodontic," and "additional root fracture." Based on these complications, the outcome was graded as "success," "partial success," "survival," and "failure." Statistics was performed by t test, chi-square test and logistic regression models. RESULTS: After 8.5 ± 4.6 years, 76.5% (39/51) of the TT had functionally survived. Functional survival of the reattached fragments was 66.7% (26/39) after 9.5 ± 3.7 years. PPD (TT: 4.11 ± 2.03; CT: 2.08 ± 0.65), CAL (TT: 4.78 ± 2.19; CT: 2.42 ± 1.03), and BoP values (TT: 77.4%; CT: 22.6%) were higher in TT than in CT. GI scores > 0 were found in 83.3% of the TT and in 27.8% of the CT. PI scores did not differ between TT and CT. Of the complications, 56.8% were "restorative," 22.7% "endodontic," and 20.5% "additional root fractures." Eleven (27.5%) TT were without complications and rated as "success." CONCLUSIONS: AFR in crown-root fractured teeth showed a high survival rate and occasionally compromised periodontal health. However, due to the high complication rate, it should be considered as a long-term temporary treatment to postpone other invasive therapy options. AFR can be a valuable way to avoid early loss of crown-root fractured teeth, especially in young patients. Moisture control and additional root fractures significantly influenced the outcome.

Effect of coded healing abutment height and position on the trueness of digital intraoral implant scans.

STATEMENT OF PROBLEM: Information regarding the effect of the height and position of a coded healing abutment (CHA) on the trueness of intraoral digital scans is lacking. PURPOSE: The purpose of this in vitro study was to investigate the effect of the height and position of a scannable CHA on the trueness (distance and angular deviations) of intraoral digital scans. MATERIAL AND METHODS: Scannable CHAs (BellaTek Encode Impression system; Zimmer Biomet Dental) were used in 2 different height pairs (3 mm and 8 mm) on 2 implants at mandibular left second and first molar positions. Each pair was scanned 10 times by using 1 intraoral scanner (TRIOS; 3Shape) by 1 operator to generate a total of 20 intraoral scan files. Master standard tessellation language (STL) files were created for both 3-mm and 8-mm CHA pairs by using a structured blue light scanner (COMET L3D 8M 150 Precision Structured Blue Light Scanner; ZEISS). These master STL files were imported into a software program (PolyWorks Inspector) and were used as the reference for the inspection. Scans obtained by using the intraoral scanner were aligned to the reference scan by using a best-fit alignment to measure the distance and angular deviations. Two-way repeated-measures ANOVA was used to analyze the data, and the Tukey-Kramer test was used to determine significant differences among groups (α=.05). RESULTS: The CHA position had a significant effect on distance deviation (P<.001). However, no significant effect of CHA height on distance deviation was found. The interaction between CHA height and position had a significant effect on the angular deviation (P=.041). The 3-mm posterior CHA (P=.026) and 8-mm anterior CHA (P=.039) had significantly lower angular deviations than the 8-mm posterior CHA. CONCLUSIONS: The distance deviation of CHA was significantly influenced by position. CHAs in the anterior had lower distance deviations for both 3 mm and 8 mm. The effect of CHA height on distance deviation was found to be small and was affected by the location of the CHA. Height affected angular deviation depending on the position of the CHA. Both 3-mm posterior and 8-mm anterior CHAs showed lower angular deviations than the 8-mm posterior CHA.

Cathepsin A Mediates Ventricular Remote Remodeling and Atrial Cardiomyopathy in Rats With Ventricular Ischemia/Reperfusion.

After myocardial infarction, remote ventricular remodeling and atrial cardiomyopathy progress despite successful revascularization. In a rat model of ventricular ischemia/reperfusion, pharmacological inhibition of the protease activity of cathepsin A initiated at the time point of reperfusion prevented extracellular matrix remodeling in the atrium and the ventricle remote from the infarcted area. This scenario was associated with preservation of more viable ventricular myocardium and the prevention of an arrhythmogenic and functional substrate for atrial fibrillation. Remote ventricular extracellular matrix remodeling and atrial cardiomyopathy may represent a promising target for pharmacological atrial fibrillation upstream therapy following myocardial infarction.

In vitro investigation of chemical properties and biocompatibility of neurovascular braided implants.

Braiding of Nitinol micro wires is an established technology for the manufacturing of fine-meshed neurovascular implants for tortuous vessel geometries. Electropolishing of wires before the braiding process has the potential to improve the in vitro behaviour in terms of thrombogenicity and endothelial cell proliferation. In this study, we present the first in vitro investigation of braided electropolished/blue oxide Nitinol samples in a blood flow loop, showing a significantly lower activation of the coagulation pathway (represented by the TAT III marker) and a tendency towards reduced platelet adhesion. Furthermore, we applied the same surface treatment on flat disks and measured protein adhesion as well as endothelial cell proliferation. We compared our results to non-electropolished samples with a native oxide surface. While platelet deposition was reduced on electropolished/blue oxide surface, a significant increase of endothelial cell seeding was observed. Investigation of inflammatory marker expression in endothelial cells provided divergent results depending on the marker tested, demanding closer investigation. Surface analysis using Auger electron spectroscopy revealed a thin layer mainly consisting of titanium oxynitride or titanium oxide + titanium nitride as a potential cause of the improved biological performance. Translated to the clinical field of intracranial aneurysm treatment, the improved biocompatibility has the potential to increase both safety (low thrombogenicity) and effectiveness (aneurysm neck reconstruction).

A comparison of implant complications and failures between the maxilla and the mandible.

STATEMENT OF PROBLEM: Identifying factors that affect the clinical outcomes of implant therapy is important. PURPOSE: The purpose of this retrospective study was to determine whether implant location was a factor affecting the complication and failure rates of single-tooth implant-supported restorations in a predoctoral setting. MATERIAL AND METHODS: The charts of 431 patients treated with a surgically placed dental implant and restored with a single crown in the predoctoral clinic were analyzed. Data on implant location, type of complication (surgical or prosthetic), and type of failure were collected and analyzed according to implant location using the Fisher Exact Test and Mantel-Haenszel Exact Chi Square Test analysis (α=.05). RESULTS: The charts revealed 158 complications (68 surgical and 90 prosthetic) in 110 patients, and 3.9% of the implants failed. No statistically significant difference was found between the number of surgical complications or prosthetic complications in the maxilla and the mandible (P=.469). CONCLUSIONS: Jaw location (maxilla compared with mandible) of the implant had no statistically significant impact on the incidence of surgically or prosthetically related complications. No statistically significant difference was found in overall implant failures, surgical failures, and prosthetic failures between maxillary and mandibular implants.

Physicochemical code for quinary protein interactions in Escherichia coli.

How proteins sense and navigate the cellular interior to find their functional partners remains poorly understood. An intriguing aspect of this search is that it relies on diffusive encounters with the crowded cellular background, made up of protein surfaces that are largely nonconserved. The question is then if/how this protein search is amenable to selection and biological control. To shed light on this issue, we examined the motions of three evolutionary divergent proteins in the Escherichia coli cytoplasm by in-cell NMR. The results show that the diffusive in-cell motions, after all, follow simplistic physical-chemical rules: The proteins reveal a common dependence on (i) net charge density, (ii) surface hydrophobicity, and (iii) the electric dipole moment. The bacterial protein is here biased to move relatively freely in the bacterial interior, whereas the human counterparts more easily stick. Even so, the in-cell motions respond predictably to surface mutation, allowing us to tune and intermix the protein's behavior at will. The findings show how evolution can swiftly optimize the diffuse background of protein encounter complexes by just single-point mutations, and provide a rational framework for adjusting the cytoplasmic motions of individual proteins, e.g., for rescuing poor in-cell NMR signals and for optimizing protein therapeutics.

Intestinal Barrier Function and the Gut Microbiome Are Differentially Affected in Mice Fed a Western-Style Diet or Drinking Water Supplemented with Fructose.

Background: The consumption of a Western-style diet (WSD) and high fructose intake are risk factors for metabolic diseases. The underlying mechanisms are largely unclear.Objective: To unravel the mechanisms by which a WSD and fructose promote metabolic disease, we investigated their effects on the gut microbiome and barrier function.Methods: Adult female C57BL/6J mice were fed a sugar- and fat-rich WSD or control diet (CD) for 12 wk and given access to tap water or fructose-supplemented water. The microbiota was analyzed with the use of 16S rRNA gene sequencing. Barrier function was studied with the use of permeability tests, and endotoxin, mucus thickness, and gene expressions were measured.Results: The WSD increased body weight gain but not endotoxin translocation compared with the CD. In contrast, high fructose intake increased endotoxin translocation 2.6- and 3.8-fold in the groups fed the CD + fructose and WSD + fructose, respectively, compared with the CD group. The WSD + fructose treatment also induced a loss of mucus thickness in the colon (-46%) and reduced defensin expression in the ileum and colon. The lactulose:mannitol ratio in the WSD + fructose mice was 1.8-fold higher than in the CD mice. Microbiota analysis revealed that fructose, but not the WSD, increased the Firmicutes:Bacteroidetes ratio by 88% for CD + fructose and 63% for WSD + fructose compared with the CD group. Bifidobacterium abundance was greater in the WSD mice than in the CD mice (63-fold) and in the WSD + fructose mice than in the CD + fructose mice (330-fold).Conclusions: The consumption of a WSD or high fructose intake differentially affects gut permeability and the microbiome. Whether these differences are related to the distinct clinical outcomes, whereby the WSD primarily promotes weight gain and high fructose intake causes barrier dysfunction, needs to be investigated in future studies.

Mechanical properties and DIC analyses of CAD/CAM materials.

BACKGROUND: This study compared two well-known computer-aided-design/computer-aided-manufactured (CAD/CAM) blocks (Paradigm MZ100 [3M ESPE] and Vitablocs Mark II [Vita] in terms of fracture toughness (Kic), index of brittleness (BI) and stress/strain distributions. MATERIAL AND METHODS: Three-point bending test was used to calculate the fracture toughness, and the relationship between the Kic and the Vickers hardness was used to calculate the index of brittleness. Additionally, digital image correlation (DIC) was used to analyze the stress/strain distribution on both materials. RESULTS: The values for fracture toughness obtained under three-point bending were 1.87Pa√m (±0.69) for Paradigm MZ100 and 1.18Pa√m (±0.17) for Vitablocs Mark II. For the index of brittleness, the values for Paradigm and Vitablocs were 73.13µm-1/2 (±30.72) and 550.22µm-1/2 (±82.46). One-way ANOVA was performed to find differences (α=0.05) and detected deviation between the stress/strain distributions on both materials. CONCLUSIONS: Both CAD/CAM materials tested presented similar fracture toughness, but, different strain/stress distributions. Both materials may perform similarly when used in CAD/CAM restorations. Key words:Ceramic, CAD/CAM, hybrid materials, composite resin, fracture toughness.