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.

In recent years, the rapid advancement of digital technology has led to a significant increase in the use of 3D printers. 3D printing technologies, which are widely used in fields such as aviation, the defense industry, art, and design, have also gained importance in dentistry. By utilizing various materials and methods, these technologies have enhanced both patient and physician comfort, while reducing working time. The numerous benefits of innovations brought by digital technologies have made them increasingly popular. Today, 3D printing is used in various dental applications, including the production of guides for maxillofacial surgery, the creation of models for orthodontics, gingival surgery, removable and fixed crown bridge prostheses in prosthetic dental treatments, as well as the production of dental implants. It is also used as a space maintainer in pediatric dentistry. The purpose of this review is to provide a general overview of the use of light-cured resins in the 3D production process. Additionally, this review aims to offer insights into additive manufacturing technologies, the materials used in these technologies, and their respective advantages and disadvantages.

Operative dental procedures may promote pulpal infections, such as tooth cavity, trauma and teeth abrasion, anaerobic microorganism colonization causing total pulp necrosis, and periapical lesions that result in bone destruction in the periapical region. Periapical radiographs are important tools for identifying periapical pathologies. However, given that the imaging system shows three-dimensional formations in two dimensions, the knowledge about the actual size of the lesion and the real relationship with the anatomic structures is limited. These limitations force clinicians to choose the high resolution and current imaging methods that show all the details of the oral structures, such as conic beam computed tomography (CBCT). CBCT is a highly effective diagnostic device for early period bone lesion detection in which the gray value for bone density is measured in Hounsfield unit (HU). Other than using CBCT, bone mineral density measurement can be done to assess the healing of existing lesions. When the periapical lesion is healing, a series of formation and destruction processes follow each other. On the one hand, mediators and tissues that must be removed from the region are destroyed by host defense cells; on the other hand, cells included in the repair process provide new tissue generation and remodelling to provide the pre-disease anatomic properties in the lesion region. This review discusses recent studies using current three-dimensional imaging methods, compared with traditional methods for bone damage due to periapical lesion formation and healing after suitable treatment. This study aims to investigate the advantages and shortcomings of existing treatment and diagnosis approaches in endodontic periradicular lesion diagnosis and treatment. The findings highlight promising diagnosis and treatment tools and suggest the expansion of minimally invasive approaches to eliminate the problems in periapical lesions. How to cite this article: How to cite this article: Akın Tartuk G, Tekin Bulut E. The effects of periapical lesion healing on bone density. Int Dent Res 2020;10(3):90-9. https://doi.org/10.5577/intdentres.2020.vol10.no3.5 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Aim: This study aimed to compare ethylenediaminetetraacetic acid (EDTA), phytic acid, and citric acid as chelation agents in final irrigation procedures on teeth with apical impermeability. Methodology: We used 66 mandibular premolar teeth with a single root and single canal extracted for periodontal or orthodontic reasons. All teeth crowns were removed to achieve a 14-mm root length. Mechanical preparation of the root canal was completed with a Reciproc R25 (VDW, Munich, Germany) file system. Teeth were randomly separated into three groups: Group 1: 5 ml 17% EDTA, Group 2: 5 ml 1% phytic acid, and Group 3: 5 ml 20% citric acid. We used 6 ml 5.25% sodium hypochlorite (NaOCl) in the mechanical preparation of all groups. Three teeth were selected for both the positive and negative control groups. All teeth in the experimental groups were filled by the lateral condensation method using AH Plus canal sealer and gutta-percha. For hardening of the canal sealer, samples were kept at 37 oC and at 100% humidity in a drying oven for 7 days. Later, following removal from the drying oven, two layers of nail polish were used to cover all but the apical 2 mm of each tooth. The teeth were then kept in 2% methylene blue solution at 37 oC for 7 days. The root was divided by cutting in the buccolingual direction and gutta-percha was removed. The dye leakage was measured linearly in millimeters (mm) under a stereomicroscope. Results: As a result of the apical leakage assessment, the lowest apical leakage is observed in the phytic acid group. There was a statistically significant difference between the phytic acid group and citric acid group. There was no statistically significant difference between other groups. Conclusion: While phytic acid showed similar results with EDTA on apical impermeability, it was more effective than citric acid. How to cite this article: Akın Tartuk G, Kaya S, Adıgüzel Ö. The effect of different final irrigation solutions on apical impermeability. Int Dent Res 2021;11(Suppl.1):201-5. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.28 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Calcium silicate-based cements are hydraulic biomaterials that form a calcium silicate hydrate (C-S-H) gel during hydration, a process fundamental to their setting and progressive physicochemical development. Although these materials are widely used in vital pulp therapy, evidence regarding the effects of adhesive strategy and restoration timing on bonding performance, particularly for newer premixed formulations, remains limited. This study evaluated the effects of cement type, adhesive strategy, and restoration timing on the shear bond strength (SBS) of resin composite bonded to MTA Angelus and Well-Root PT. A total of 270 specimens were distributed across two cement types, three adhesive strategies, and three restoration intervals (45 min, 24 h, and 7 days). After thermocycling, SBS and failure modes were assessed. SBS data were analyzed using three-way ANOVA, whereas failure-mode distributions were evaluated using chi-square or Fisher’s exact tests (α = 0.05). Cement type, adhesive strategy, restoration timing, and their interactions significantly influenced SBS (p < 0.001). Well-Root PT exhibited higher early bond strength than MTA Angelus. The two-step etch-and-rinse adhesive produced the highest SBS values, whereas the universal adhesive produced the lowest. Restoration after 24 h significantly increased SBS compared with restoration after 45 min, with no additional improvement observed at 7 days. Within the limitations of this in vitro study, bonding performance was influenced by cement type, adhesive strategy, and restoration timing. The time-dependent increase in SBS is consistent with continued hydration and development of the C-S-H gel-based cement matrix, although the specific microstructural changes underlying this behavior were not directly characterized.

Effective endodontic irrigation requires smear layer removal while preserving dentin integrity. Although multifunctional irrigants combine disinfection and chelation in a single solution, the effects of thermal activation on their behavior and dentin interaction remain unclear. The aim of this in vitro study was to evaluate the effects of temperature protocols on smear layer removal, dentin erosion, and selected physicochemical properties of Triton All-in-One irrigation solution. Ninety extracted single-rooted mandibular premolars were prepared with a Reciproc R25 file and irrigated exclusively with Triton. Using an in vitro experimental model, apical and external root surface temperatures were monitored with thermocouples. Specimens were assigned to room-temperature irrigation (22 °C), preheated irrigation (60 °C), or intracanal heating for 5, 10, or 15 s. Smear layer removal and dentin erosion were evaluated by scanning electron microscopy using modified Hülsmann criteria. As complementary analyses, the physicochemical properties of the Triton irrigation solution, including pH, available chlorine, and surface tension, were assessed, together with calcium ion release following dentin interaction. Intracanal temperature change (ΔT = Tmax − T0) differed significantly among the experimental groups ( p < 0.001), with progressively greater increases observed as the duration of intracanal heating increased. External root-surface temperature increases remained below 2 °C in all specimens under the present experimental conditions. Temperature elevation enhanced smear layer removal by Triton ( p < 0.001), reduced surface tension, and increased calcium ion release. Preheated irrigation improved smear layer removal compared with room-temperature irrigation while producing lower erosion scores and reduced calcium ion release than prolonged intracanal heating. Thermal activation enhanced the cleaning efficacy of Triton; however, dentin alteration depended on the thermal protocol. Preheated irrigation improved smear layer removal while producing less dentin erosion and calcium ion release than prolonged intracanal heating. The clinical significance of these findings requires further functional validation.