Abstract Background Restoration of endodontically treated teeth (ETT) with significant coronal loss poses a challenge in clinical dentistry. Advances in CAD/CAM technology and biomimetic materials have introduced minimally invasive approaches, such as endocrowns and overlays, which can replace traditional post-core and crown approach. Aim The aim of this in-vitro study was to comparatively assess the mechanical behaviour of two restorative designs (endocrowns and overlays) fabricated from two CAD/CAM materials in endodontically treated mandibular molars. Materials and methods Thirty-six endodontically treated lower molars (n = 36) were split into two main groups based on restoration type (n = 18): endocrowns and overlays. Each group was further subdivided into two subgroups based on the CAD/CAM material (n = 9): lithium disilicate (Tessera) and indirect composite (Crios). Restorations were fabricated and bonded to their respective specimens following a strict bonding protocol with an adhesive resin cement (Bisco self-adhesive). Thermo-mechanical aging (Chewing Simulator CS-4, SD Mechatronic) was conducted to simulate oral conditions, followed by a universal testing machine's evaluation of fracture resistance. The test was stopped after fracture. Fractured parts were analysed to determine mode of failure. Data were analyzed using two-way ANOVA followed by Tukey’s honestly significant difference (HSD) test for pairwise comparisons (α = 0.05). Results All specimens survived the 5,000 chewing cycles, simulating early intraoral service. Fracture resistance test showed significantly higher fracture resistance for overlays (2048.46 ± 664.63 N) than endocrowns (1234.54 ± 338.50 N) (p = 0.002). Crios overlays exhibited the highest fracture resistance (2384.60 ± 631.10 N), significantly outperforming Tessera overlays (1712.33 ± 559.59 N) (p = 0.043) and endocrowns (1354.20 ± 346.88 N) (p = 0.004). No substantial material change was seen in endocrown restorations (p = 0.445). Conclusion Overlay restorations and indirect composite material (Crios) provide superior resistance to fracture compared to lithium disilicate overlays and endocrowns and may represent a reliable restorative option for endodontically treated molars.
Periodontitis is commonly known as a chronic inflammatory disease which adversely affects pulpal and periodontal tissues, including odontoblasts. Bone marrow mesenchymal stem cell-derived exosomes (BM-MSC-Exo) and nanocurcumin (NCUR) possess anti-inflammatory and regenerative properties; however, their combined effects on odontoblasts remain insufficiently explored. The research target was to assess the histological, histochemical, and anti-inflammatory effects of BM-MSC-Exo and NCUR-loaded BM-MSC-Exo on odontoblasts of LPS-induced periodontitis in rats. Twenty-eight male albino rats were assigned at random into four groups (n = 7 each): control, periodontitis, periodontitis treated with BM-MSC-Exo, and periodontitis treated with NCUR-loaded BM-MSC-Exo. Periodontitis was induced via intra-periodontal LPS injections. Histological evaluation was performed using hematoxylin and eosin staining, and collagen synthesis was analyzed using Masson’s trichrome stain. Morphometric analysis of newly formed collagen and enzyme-linked immunosorbent assay (ELISA) of interleukin-10 (IL-10) levels were conducted. Untreated periodontitis caused marked odontoblastic degeneration, reduced predentin thickness, and decreased collagen formation. Treatment with BM-MSC-Exo significantly improved odontoblastic architecture, enhanced collagen deposition, and increased IL-10 expression. NCUR-loaded BM-MSC-Exo demonstrated superior regenerative and anti-inflammatory effects, characterized by improved odontoblastic organization, increasing the area of newly formed collagen, and significantly elevated IL-10 levels compared with all other groups (p < 0.001). BM-MSC-Exo exerts regenerative effects on odontoblasts in periodontitis, which are further enhanced by NCUR loading. NCUR-loaded BM-MSC-Exo declares an encouraging cell-free medicinal strategy for regeneration of periodontal and pulpal tissues.
Pit and fissure sealants are widely used for caries prevention; however, their long-term success depends largely on retention. Giomer-based sealants containing surface pre-reacted glass ionomer fillers offer bioactive properties, yet concerns remain regarding their bonding durability when applied with mild self-etch primers. This randomized clinical trial evaluated the effect of bioactive glass air-abrasion pretreatment on the retention and caries preventive efficacy of a giomer-based sealant in young adults over 12 months. This parallel-arm randomized clinical trial included 96 participants, each contributing one eligible sound permanent molar (n = 48 per group). Participants were randomly allocated to either bioactive glass air-abrasion pretreatment followed by application of a giomer-based sealant (intervention group) or application of the same sealant without pretreatment (comparator group). Sealant retention and secondary caries incidence were evaluated at baseline, 6 months, and 12 months using Simonsen’s criteria, and modified United States Public Health Service (USPHS) criteria, respectively. The primary outcome was sealant retention at 12 months, whereas secondary caries incidence was assessed as a secondary outcome. Intergroup comparisons were analyzed using the Chi-square test. Intragroup comparisons were analyzed using Cochran’s Q test followed by multiple comparisons. Relative risk with 95 https://clinicaltrials.gov/ , (NCT06003452), 15-08-2023.
Conventional full-coverage anterior crown preparations for zirconia often require substantial enamel and dentine reduction and may concentrate palatal-cervical stresses, risking marginal discrepancy and compromised seal. A conservative “Mini-skirt” (MS) design that positions the palatal finish line coronally (above the cingulum) could preserve tooth structure and enhance adhesive support, but its thermo-mechanical performance under thermal cycling and fatigue loading remains unclear. To evaluate whether a conservative MS anterior preparation, with a palatal finish line above the cingulum, improves the thermo-mechanical behavior of generation-5 zirconia crowns compared with a conventional full-coverage (CF) design. Sixty extracted maxillary central incisors were randomly assigned to MS or CF groups (n = 30). Monolithic 4Y zirconia crowns were CAD/CAM-manufactured, air-abraded and adhesively luted. Specimens were thermocycled 10,000 times between 5 °C and 55 °C, then obliquely loaded at 45° for 1.7 × 10⁶ cycles (50 N, 2 Hz); survivors underwent static fracture testing (0.5 mm·min⁻¹). Marginal gaps were quantified from silicone replicas; failures were classified Grades I–IV (restorable = I–III). Finite-element models ( 1.3 M elements) reproduced boundary conditions to map stress. The MS preparation endured thermo-mechanical ageing markedly better than CF: 93.3
Early childhood caries (ECC) is one of the most common chronic conditions affecting children worldwide, with more than 530 million children affected. In Qatar, ECC prevalence among preschool children aged 4–5 years is reported at 89
