Search Results (42)

Background: The integration of additive manufacturing (AM) into digital dentistry has extended 3D printing beyond auxiliary applications toward the fabrication of definitive restorations, yet the evidence remains dispersed across diverse materials and technologies. This scoping review aimed to map the available evidence on 3D-printed resin- and ceramic-based materials for definitive tooth-supported restorations, including crowns, fixed dental prostheses, endocrowns, veneers, overlays, and onlays. Methods: The review followed the JBI framework and reported according to PRISMA-ScR. MEDLINE, Embase, and Scopus were searched from inception to April 2026. Two reviewers screened records independently against predefined eligibility criteria, and data were extracted using a piloted charting form capturing study design, materials, additive manufacturing technology, restoration type, and evaluated outcomes. Given the anticipated heterogeneity, extracted data were synthesised descriptively and mapped narratively rather than pooled statistically; 111 studies met the inclusion criteria. Results: The evidence was predominantly in vitro (105 studies), with only six clinical studies, including one randomised controlled trial. Research concentrated on single crowns, zirconia and ceramic-filled/methacrylate-based resins, and vat-photopolymerization technologies. Additively manufactured restorations were frequently reported as comparable to milled controls in dimensional accuracy, marginal and internal fit, and fracture resistance, with values generally falling within the clinically accepted thresholds defined by the primary studies; reported outcomes were most consistent for printed zirconia, whereas printed resins were more often limited by lower strength and colour instability. Outcomes were strongly influenced by processing parameters, underscoring the need for workflow standardisation. Conclusions: The current evidence supports the technical feasibility of 3D-printed definitive restorations more strongly than their long-term clinical durability, highlighting a need for long-term clinical trials. Full article

Background and Objectives: Three-dimensional printing is increasingly used to fabricate dental restorations; however, limited evidence is available on the mechanical performance and fracture behavior of printable resin materials used for endocrown restorations. Fracture load alone may not fully describe material performance, particularly when brittle or defect-sensitive failure occurs. This in vitro study aimed to compare the fracture resistance, Weibull parameters, experimental Mode I fracture toughness parameter, and failure patterns of three 3D-printed resin materials used for endocrown restorations. Materials and Methods: Thirty anatomically identical molar replicas were produced from a single prepared tooth model and restored with endocrowns fabricated from NextDent C&B MFH (NextDent B.V., Soesterberg, The Netherlands), SprintRay Crown (SprintRay Inc., Los Angeles, CA, USA), and BEGO VarseoSmile Crown Plus (BEGO GmbH & Co. KG, Bremen, Germany) (n = 10/group). The restorations were cemented and subjected to compressive loading until fracture. Maximum fracture force values were analyzed using Welch’s ANOVA and Weibull statistics. In parallel, single-edge-notched bend (SENB) specimens were fabricated from the same materials and tested using an ASTM D5045-based configuration to calculate an experimental Mode I fracture toughness parameter. Representative fractured crowns and standardized specimens were examined using stereomicroscopy to assess visible failure morphology. Results: No statistically significant difference in maximum fracture force was found among the three materials (Welch’s ANOVA, p = 0.217). The mean fracture force values were 862.37 N for NextDent C&B MFH, 804.37 N for SprintRay Crown, and 699.43 N for BEGO VarseoSmile Crown Plus. In the complementary analyses, BEGO VarseoSmile Crown Plus showed the highest Weibull modulus (m = 9.36), indicating a narrower distribution of fracture values, and the highest mean experimental Mode I fracture toughness parameter (5.250 MPa·m^0.5) under the present experimental conditions. Qualitative stereomicroscopic analysis revealed material-dependent visible failure patterns: SprintRay Crown exhibited more extensive fragmentation, whereas BEGO VarseoSmile Crown Plus showed a more defined visible fracture pattern with less secondary fragmentation. Conclusions: Fracture load alone was insufficient to characterize the mechanical behavior of the tested materials fully. Weibull parameters, the experimental fracture toughness parameter, and failure morphology provided complementary information and should be considered when evaluating 3D-printed resin materials for endocrown restorations. Full article

This study evaluated the effects of two different restorative assemblies and restorative material type on the fracture resistance of indirect composite restorations in simulated revitalized immature maxillary central incisors. Forty-eight extracted maxillary central incisors were randomly assigned to four groups (n = 12): breCAM.HIPC endocrowns, Gradia Plus endocrowns, breCAM.HIPC crowns, and Gradia Plus crowns. Following a standardized revitalization protocol, restorations were performed and specimens were thermocycled. Fracture resistance was assessed under oblique compressive loading, and fracture patterns were recorded. Data were analyzed using two-way ANOVA and Fisher’s exact test (α = 0.05). The tested restorative assembly significantly influenced fracture resistance (p < 0.05), whereas material type did not (p > 0.05). Endocrown restorations exhibited higher fracture resistance than crown restorations regardless of material. No statistically significant material-related differences were detected within the same restorative assembly. Crown restorations showed a higher incidence of coronal fractures. These findings indicate that, under the experimental conditions of this in vitro study, the tested endocrown restorations demonstrated higher fracture resistance than the Trinia core-supported crown restorations. However, because the two groups differed not only in restoration design but also in their internal structural configuration, including the use of fiber-reinforced composite cores only in the crown groups, the findings should be interpreted as reflecting the performance of the tested restorative assemblies rather than the isolated effect of restoration design. Full article

This study evaluated the effects of restorative material, restoration type, and fiber strip reinforcement on the fracture strength (FS) of endocrown (EC) and post-core (PC) restorations in endodontically treated premolars. Specimens were allocated according to restorative material [resin-nanoceramic (RNC) or feldspathic ceramic (FC)], restoration type (EC or PC), and reinforcement [fiber strip-reinforced (FR) or -non-reinforced (NF)]. FS was determined using a universal testing machine under axial loading. Statistical analysis was performed using three-way ANOVA and Bonferroni tests (α = 0.05). Material, restoration type, and reinforcement significantly affected FS (p < 0.05). RNC restorations exhibited higher FS than FC restorations (861 ± 181 N vs. 715 ± 212 N; p < 0.001). EC restorations exhibited higher FS than PC restorations (828 ± 173 N vs. 748 ± 236 N; p = 0.046). FR groups exhibited higher FS than NF groups (848 ± 180 N vs. 728 ± 222 N; p = 0.003). The highest FS was observed in the RNC–PC–FR group (965 ± 144 N), whereas the lowest occurred in the FC–PC–NF group (480 ± 177 N). Although EC restorations showed higher FS than PC restorations, the effect of restoration type depended on material and reinforcement. Full article

This study investigated the effect of CAD-CAM resin composite thickness on the polymerization behavior of dual-cure resin cements used for endocrown restorations. Three commercially available dual-cure resin cements and one light-cure resin cement (for comparison) were polymerized by light irradiation through CAD-CAM resin composite plates of varying thicknesses (1.5, 3.5, 5.5, 7.5, and 9.5 mm). Transmitted light intensity was measured using an optical spectrometer. Polymerization behavior was evaluated immediately after irradiation and after 24 h of aging using Fourier transform infrared spectroscopy to determine the degree of conversion (DC) and Vickers hardness (VH) testing. Transmitted light intensity decreased logarithmically with increasing composite thickness, with less than 1% of incident light reaching the resin cement at thicknesses ≥ 5.5 mm. For the dual-cure resin cements, DC and VH values significantly decreased when the composite thickness exceeded 5.5 mm. Although DC and VH increased after 24 h due to self-curing, values beneath thicker composites remained lower than those beneath 1.5 mm thick composites. The light-cure resin cement failed to polymerize when the composite thickness exceeded 7.5 mm. These results indicate that CAD-CAM resin composite thickness critically influences resin cement polymerization, highlighting the importance of thickness control in endocrown restorations. Full article

A three-dimensional finite element analysis (FEA) was performed to evaluate stress accumulation and distribution in endodontically treated immature and mature mandibular molars restored with endocrowns. Three tooth models representing different stages of root development (Cvek 2, Cvek 3, and mature) were generated from cone-beam computed tomography data. Endocrowns were fabricated using lithium disilicate (LDS) and resin nanoceramic (RNC). In immature teeth, two apexification strategies were simulated: a 3 mm mineral trioxide aggregate (MTA) apical plug followed by gutta-percha obturation, and complete canal obturation with MTA. All models were subjected to axial (600 N) and oblique (200 N) loading. A total of 20 finite element models were analysed. Endocrown material and loading direction were the main factors affecting von Mises stress distribution, whereas root development stage and apexification technique showed limited influence. LDS resulted in reduced stress transmission to the residual dentin, despite higher stress accumulation within the restoration itself. In the LDS groups, von Mises stress values in the root dentin ranged from 35.24 to 35.96 MPa under oblique and from 42.93 to 44.45 MPa under axial loading, while the RNC group exhibited higher values (39.36–40.40 MPa and 51.59–53.66 MPa, respectively). These findings indicate that endocrown restoration after apexification is a reliable treatment option for immature mandibular molars with extensive structural loss, with LDS demonstrating more favorable biomechanical behavior. Full article

The restoration of endodontically treated teeth remains a clinical challenge, particularly when substantial coronal tissue loss is present. Endocrowns fabricated using CAD/CAM technologies offer a conservative and esthetic alternative to conventional post-core systems; however, their long-term performance may be influenced by age-related mechanical and thermal stresses. This study evaluated the effect of thermomechanical aging on the marginal adaptation and fracture resistance of endocrowns fabricated from three CAD/CAM materials: zirconia-reinforced lithium silicate (ZLS), polyetherether ketone (PEEK), and 3D-printed resin. Sixty extracted human molars were endodontically treated and restored with endocrowns produced from these materials (n = 20 per group) and then subdivided into aged (n = 10) and control (n = 10) subgroups. Thermomechanical aging involved 5000 thermal cycles between 5 °C and 55 °C, and 75,000 mechanical loading cycles at 50 N. Marginal gaps were examined using scanning electron microscopy, and fracture resistance was tested under axial load at a crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA followed by Tukey’s post hoc test (α = 0.05). Thermomechanical aging significantly increased the marginal gaps in all materials (p < 0.05). The smallest marginal discrepancies were observed in the 3D-printed resin group, while the largest occurred in the ZLS after aging, likely due to dimensional changes during crystallization. Fracture resistance decreased in ZLS (−21.2%) and 3D resin (−20.9%) after aging (p < 0.05) but was not significantly affected in PEEK (−5.4%, p = 0.092). Thermomechanical aging adversely affects marginal adaptation across all materials, whereas its impact on strength is material-dependent. PEEK demonstrated the most stable mechanical performance and may represent a promising alternative for long-term endocrown restorations. Full article

Background: Smoking alters oral ecological balance, yet its influence on posterior teeth restored with lithium disilicate endocrowns is insufficiently documented. This study assessed the clinical and microbiological impact of smoking on the peri-coronal environment of endocrown-restored teeth, using an age-stratified approach to evaluate cumulative effects. Methods: A cross-sectional study was conducted on 100 adults, equally divided into smokers and non-smokers. Salivary pH, papillary bleeding index, and plaque index were clinically recorded. Subgingival samples collected from endocrown-restored posterior teeth were analyzed using a polymerase chain reaction (PCR) assay targeting major periodontal pathogens. Age-related variation in clinical and microbiological parameters was examined using one-way analysis of variance (ANOVA), followed by Tukey’s HSD post hoc test. Results: Smokers showed consistently lower salivary pH and higher plaque accumulation across all age groups. Gingival bleeding was reduced in younger smokers but increased in older individuals. Microbiological analysis identified markedly elevated levels of orange-complex organisms in smokers, including Prevotella intermedia and Fusobacterium nucleatum. Clinically, endocrowns in smokers presented more frequent marginal degradation, localized inflammation, and early signs of recurrent caries. These effects intensified with age. Conclusions: Smoking adversely modifies the peri-coronal biological environment of lithium disilicate endocrowns by increasing acidity, promoting plaque maturation, and supporting dysbiotic microbial communities. Age further amplifies these changes. Considering smoking status and patient age during treatment planning may improve long-term restorative outcomes. Full article

Purpose: This study aimed to evaluate the effect of different coronal restoration methods on stresses in immature central incisors with regenerative endodontic treatment and excessive loss of coronal structure. Methods: A three-dimensional (3D) Finite Element Analysis (FEA) model of a maxillary central incisor treated with a 3 mm MTA coronal plug after regenerative endodontic treatment was created. Six different models were simulated: (1) intact immature tooth (control), (2) direct composite resin build-up, (3) fibre-reinforced composite build-up, (4) hybrid ceramic endocrown, (5) LiSi ceramic endocrown, and (6) endocore and ceramic crown restoration. Analyses were performed with SolidWorks/CosmosWorks, and a 150 N load was applied at a 135° angle. Results: Maximum tensile stresses were concentrated in the cervical region (4.577 MPa). Direct composite and fibre-reinforced restorations showed high stress in root dentin (3.891 and 3.841 MPa, respectively). The endocore/ceramic crown restoration (1.578 MPa) provided the closest stress distribution to the natural tooth (1.322 MPa). Conclusions: The biomechanical performance of the restoration–tooth complex depends on both the restorative material and the restoration design. In immature teeth undergoing regenerative endodontic treatment, the most biomechanically favourable restoration option was an endocore/ceramic crown. Full article

Aim: To compare the fracture resistance of teeth with varying degrees of residual coronal dentine after restoration using two fibre-reinforced composite core materials. Materials and Methods: Seventy extracted human lower premolars were divided into four groups: sound (control), one missing proximal wall (Cl-II), two missing proximal walls (MOD), and endocrown (EC). Subgroups were restored with either a short fibre-reinforced flowable composite (EverX Flow) or an experimental fibre-reinforced composite. Except for the control, teeth underwent endodontic treatment and were restored accordingly. Fracture resistance was tested using a universal testing machine. Statistical analysis compared fracture resistance across groups. Results: Teeth in EC exhibited the highest fracture resistance (1153.43 ± 332.52 N), comparable to sound teeth (1114.03 ± 185.58 N) and not significantly different from the experimental composite group (1006.89 ± 200.51 N) (p = 0.304). Cl-II restorations with EverX had significantly lower strength (652.48 ± 314.04 N) compared to MOD (773.02 ± 261.18 N) and EC (p < 0.05). The experimental composite showed a similar trend, with MOD having the lowest strength (408.6 ± 168.85 N). Significant differences were noted between materials in the MOD group (p = 0.009). Scanning electron microscopy revealed distinct fracture patterns. Conclusions: Endocrowns using direct fibre-reinforced composites provided protection for endodontically treated teeth with higher fracture resistance compared to teeth with MOD and Cl-II cavities. This gives direct composite endocrowns a potential for high-stress applications, though design and material selection remain critical. Full article

Background and Objectives: Endocrowns have emerged as a minimally invasive restorative option in dentistry, aiming to preserve as much of the original tooth structure as possible. This scoping review investigates the success rates, biomechanical performance, and material efficacy of endocrowns for restoring molars, in comparison to conventional post-and-core crowns. Materials and Methods: A comprehensive literature review was conducted to identify relevant studies using PubMed and Scopus databases. The search covered publications up to March 2025. All study types focusing on molar restorations were included, except for case reports. Data extraction and screening were performed independently by two reviewers. Results: A total of 37 studies fulfilled the eligibility criteria. Eleven systematic reviews examined comparisons between endocrowns and post-and-core crowns, as well as differences in material selection, survival and success rates, and outcomes between molars and premolars. The remaining 26 studies addressed the clinical performance and longevity of endocrowns, with an emphasis on preparation design, adhesive protocols, and mechanical behavior related to material selection. Conclusions: Endocrown restorations present a conservative and predictable alternative to post-and-core crowns for molars with extensive coronal damage. However, due to variability in reported outcomes, high-quality randomized clinical trials are crucial for confirming their clinical effectiveness. The development of novel, standardized treatment guidelines would provide clinicians with adequate information to effectively restore endodontically treated teeth (ETT). Full article

Background/Objectives: The aim of this study was to evaluate the level of awareness among dental students and practitioners regarding the utilization of endocrowns in clinical settings, along with any differences in knowledge based on gender, educational level, and workplace. Methods: A cross-sectional online survey-based study was conducted, including 1154 participants from various dental institutions across Saudi Arabia. The questionnaire included demographic data and closed-ended questions focused on knowledge and awareness of endocrowns. Data was analyzed using statistical tests, including chi-square, to see any significant differences. Results: Most participants (81%) had knowledge about endocrowns, mainly from their colleagues. Knowledge levels and preferences (like the use of lithium disilicate and adhesive resin cement) differed based on gender, educational level, and workplace. Male participants and undergraduates showed better awareness in some areas. Faculty members mostly depend on college training, while private practitioners obtain most of their information from workshops. Conclusions: Males showed significant superiority in knowledge about endocrown usage. Colleges were the most prevalent source of information regarding endocrown restorations. Significant molar tooth loss and restricted inter-arch space were the most common reasons for utilizing endocrowns. Moreover, endocrowns were considered a viable alternative to traditional post and core. Full article

Background/Objectives: Endodontically treated molars are structurally weakened due to internal tissue loss, increasing their risk of fracture. Endocrowns, developed as a conservative alternative to post–core systems, have gained popularity with the rise of digital dentistry, CAD/CAM workflows, and 3D-printed restorations. In this context, the aim of the present pilot study was to investigate the influence of cement layer thickness, intracoronal depth, and dentine wall thickness on the fracture resistance of molars restored with 3D-printed endocrowns. Methods: Twelve extracted human molars were endodontically treated and restored with endocrowns fabricated from a 3D-printed resin material, SprintRay Crown^TM (SprintRay Inc. Los Angeles, CA, USA), via masked stereolithography (MSLA) on a Prusa SL1 printer. Cementation was performed using RelyX Universal Resin Cement (3M, Maplewood, MN USA). Cone beam computed tomography (CBCT) was used to measure the dentine thickness and intracoronal depth before cementation and cement thickness after cementation. The fracture resistance was evaluated using a universal testing machine. For each variable (Td, Dp, Tc), the 12 specimens were divided into two groups (n = 6). Statistical analysis included Pearson correlation, a one-way ANOVA, and the non-parametric Mann–Whitney U test. Results: Within the limitations of this pilot in vitro study, cement thickness demonstrated a strong positive correlation with fracture resistance (r = 0.577) and was the only variable showing statistical significance in the ANOVA (F = 7.847, p = 0.019). In contrast, intracoronal depth and dentine wall thickness exhibited weaker and nonsignificant correlations. No significant mechanical advantage was observed from increasing the pulp chamber depth or peripheral dentine wall thickness. This result was further supported by nonparametric Mann–Whitney U testing (p = 0.015). Conclusions: Cement layer thickness is a key biomechanical factor influencing the fracture resistance of endocrown restorations. Preparation depth and dentine wall geometry appear to have a less direct impact. Full article

Objective: This study aims to evaluate the stress distribution on endodontically treated anterior teeth restored using different restorative materials and different post lengths versus endocrowns employing finite element analysis (FEA). Methods: An extracted human central incisor tooth with a fully formed apex was scanned using high-resolution cone beam computed tomography (CBCT) to generate 3D finite element models. Six models of restorations of badly destructed central incisor were grouped according to the type of ceramic material and post length versus endocrown restorations. Group V-L: Vita Enamic, long post (10 mm intra-radicular), Group C-L: Celtra Duo, long post (10 mm intra-radicular), Group V-Sh: Vita Enamic, short post (3 mm intra-radicular), Group C-Sh: Celtra Duo, short post (3 mm intra-radicular), Group V-E: Vita Enamic endocrown (3 mm intra-radicular), and Group C-E: Celtra Duo endocrown (3 mm intra-radicular). A static load of 200 N was applied to the palatal surface at a 45 degree angle to the tooth’s long axis. The maximum equivalent von Mises stress and maximum principal stress were analyzed at four locations: the finish line, coronal third of the root (12 mm from the apex), middle third of the root (8 mm from the apex), and apical third of the root (4 mm from the apex). Results: Group C-L exhibited the highest maximum VM stress and PS at the finish line, in addition to the highest maximum VM stress and PS at the root apical third, while group C-Sh reported the least maximum VM stress at the root apical third among the groups. All Celtra Duo groups reported higher maximum VM stress than the corresponding groups of Vita Enamic at the finish line and root coronal thirds. However, at the root middle and apical thirds, both materials recorded similar stresses. Conclusions: Short posts and Vita Enamic endocrowns showed minimal stress, especially at the finish line, while long posts increased stress and fracture risk. The findings support conservative restorations without posts, although clinical validation is needed to confirm their long-term effectiveness and safety. Full article

The aim of this innovative study was to investigate the feasibility of a modified butt joint preparation with two grooves instead of a ferrule when root dentin tissue is limited in mandibular molars. It was also investigated to what extent the effect of these treatment options on marginal and internal fit and fracture strength (FS) varied according to the type of material and whether or not a fiber ribbon was used at the base. Marginal and internal fit were evaluated using the triple-scan protocol. Statistical analysis was conducted via a three-way analysis of variance (ANOVA). The absolute marginal discrepancy (AMD), marginal discrepancy, and overall fit values for the ceramic group were 127 μm, 108 μm, and 120 μm, respectively, while corresponding values for the hybrid ceramic group were 139 μm, 116 μm, and 130 μm (p < 0.05). The mean FS recorded for ceramic restorations was 662 N, whereas hybrid ceramic restorations demonstrated a significantly higher FS of 903 N (p < 0.001). When material type was assessed independently of preparation design and base configuration, both ceramic and hybrid ceramic exceeded the predefined clinical acceptability threshold for AMD; however, they remained within acceptable limits for the remaining parameters. Among the evaluated configurations, hybrid ceramic restorations incorporating ferrules and fiber-reinforced bases exhibited the highest FS values, whereas ceramic restorations with modified biological widths and lacking fiber reinforcement yielded the lowest FS values. Full article