Morphological and Dimensional Analysis of the Nasopalatine Canal: Insights from Cone-Beam Computed Tomography Imaging in a Large Cohort.

BACKGROUND The nasopalatine canal (NPC), or incisive canal, is located in the midline of the palate, posterior to the maxillary central incisors. Its anatomy is important in prosthetic dentistry procedures. This study aimed to assess the anatomical morphology of the NPC according to age, sex, and dental status using cone-beam computed tomography (CBCT) in 335 patients. MATERIAL AND METHODS In this retrospective cross-sectional study, a total of 335 patients were recruited and categorized according to sex, age, and dental status. Individual CBCT images were analyzed in the sagittal, coronal, and axial planes. Also, we recorded the dimensions and morphological shape of the NPC and adjacent buccal bone plate (BBP) under standardized conditions. The associations between sex, age group, NPC shapes and types, and presence of central incisors were assessed. A significance level was set at P<0.05. RESULTS Mean labio-palatal and mediolateral measurements of the incisive foramen were 5.13±1.45 mm and 3.21±0.96 mm, whereas the mean diameter of Stenson foramen was 2.57±1.25 mm, and the total length of the NPC was 11.79±2.50 mm. Funnel, Y, and round-shaped canals were the most prevalent shapes of the NPC in sagittal, coronal, and axial planes. BBP was greater in men, with P=0.011, P=0.000, and P=0.001 at BBP1, BBP2, and BBP3, respectively. CONCLUSIONS NPC and BBP parameter values were slightly higher among male patients. NPC parameters increased with older age. The crest width of BBP decreased with older age and after missing maxillary central incisor teeth.

Impact of Denture Use on Oral Health-Related Quality of Life in Yemeni Patients: A Cross-Sectional Analysis.

BACKGROUND We used the 14-item Oral Health Impact Profile-14 (OHIP-14) questionnaire to evaluate the association between sociodemographic variables and oral health-related quality of life in 241 wearers of removable partial or complete dentures attending a single center in Yemen. MATERIAL AND METHODS A total of 241 partial dentures (PD) and complete dentures (CD) wearers were enrolled from the Department of Prosthodontics at the Faculty of Dentistry, Sana'a University, and the University of Science and Technology. Data were collected before the commencement of denture wearing and after 3-6 months of denture use. The questionnaire consisted of sociodemographic information and denture type, and another for the OHIP to assess oral health-related quality of life (OHRQoL), oral health impact profile scale comprises 7 subscales, each evaluating different aspects of oral health and functionality. Descriptive statistics were calculated for participants. Independent t tests were performed to compare different patient groups, focusing on PD and CD wearers. Paired-sample t tests were used to examine changes within patient groups before and after removable denture use. RESULTS Among all participants, 67.6% were male, wearers of CDs were 74.6% male, PDs were 58.3%, and was consistent for CD (71.0%) and PD (72.8%) wearers. The wearing prostheses significantly impacted the OHRQoL of patients using both PDs and CDs (P<0.01). Among CD wearers, 4 of these subscales (3-6) were statistically significant, but the handicaps subscale showed evident reductions in physical pain after treatment among PD wearers. CONCLUSIONS Wearing dentures positively affects the OHRQoL of patients, influencing various aspects of their health, including functional, physical, psychological, and social well-being.

Nanoparticle Augmentation of Adhesive Systems: Impact on Tensile Strength in Fiberglass Post Placement within Root Dentin.

BACKGROUND Modification of the glass fiber post (GFP) with titanium dioxide or silver particles can improve the durability and reliability of dental treatments for ensuring long-term success. This research assessed the tensile bond strength (TBS) of an adhesive system used for cementing GFPs into root dentin following the incorporation of nanoparticles of titanium dioxide (NTiO2) and silver (NAg). MATERIAL AND METHODS Sixty human maxillary canines were prepared to create a 10-mm intra-radicular space for post placement from the cementoenamel junction. The specimens were randomly allocated into 2 groups (a non-thermocycling group and a thermocycling group). Each group was divided into 3 subgroups (10 samples each) according to the adhesive system used (adhesive system devoid of any addition, adhesive system including 1% NAg, and adhesive system infused with 1% NTiO2). TBS tests were conducted and recorded in MPa using a Universal Testing Machine, with an axial load applied at a rate of 0.5 mm/min until failure. The TBS for both groups (non-thermocycling and thermocycling) was measured in megapascals (MPa), and the failure type was recorded. The data were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey's test with P.

Influence of Surface Type with Coffee Immersion on Surface Topography and Optical and Mechanical Properties of Selected Ceramic Materials.

BACKGROUND The aim of this study was to assess and compare the effect of surface type (glazed or polished) with coffee immersion and aging on surface topography (Ra), optical properties (TP, OP), and mechanical properties (fracture forces and modes) of zirconia-reinforced lithium silicate (Vita Suprinity), hybrid polymer-infiltrated-feldspathic ceramic network material (Vita Enamic), and leucite-containing feldspathic glass (Vitablocs® Mark II) made by computer-aided design and computer-aided manufactured (CAD/CAM) ceramic materials. MATERIAL AND METHODS Fifty-four specimens were assembled out of the above 3 CAD/CAMs ceramic materials. Each group was divided into glazed or polished surfaces, having 9 specimens of every type and stained in coffee for 15 days. Ra and color of specimens in the form of TP and OP were recorded before and after immersion in staining material. Fracture forces and modes were analyzed after the 90-day aging. Data were analyzed using ANOVA, then post hoc analysis and Bonferroni tests. RESULTS Our study found significant differences in Ra, TP, and Op before and after coffee immersion between glazed and polished specimens, with higher values in the polished surfaces among the 3 ceramic materials. The highest values of fracture resistance were noted in Vita Suprinity, and Vita Enamic had the lowest values, without significant differences among groups. CONCLUSIONS Most of the TP and OP values were in acceptable clinical range, and Vita Suprinity had superior TP than the other groups. Reparable fracture types were observed in Vita Suprinity, whereas semi-reparable and non-reparable were predominant in other groups.

Effect of Miswak Derivatives on Color Changes and Mechanical Properties of Polymer-Based Computer-Aided Design and Computer-Aided Manufactured (CAD/CAM) Dental Ceramic Materials.

BACKGROUND Miswak is a form of chewing stick used to clean teeth in different parts of the world, including Saudi Arabia. We present a description of the effects of miswak derivatives, namely toothpaste, mouthwash, and brushing sticks, on the mean color changes (DE00), compressive fracture resistance values, and fracture modes of polymer-based computer-aided design (CAD) and computer-aided manufactured (CAM) prosthetic materials. MATERIAL AND METHODS Eighty-one rectangular-shaped samples were prepared from lithium disilicate glass-ceramic (IPS e.max CAD), zirconia-reinforced lithium silicate (Vita Suprinity), and monochromatic tooth-colored feldspar (Vitablocs Mark II) CAD/CAM ceramics. The color parameters were recorded using spectrophotometer before and after exposing the specimens to the different miswak oral hygiene derivatives for 15 days. Compressive fracture resistance values and fracture types were also assessed, and statistical analysis was performed. RESULTS Vita Suprinity and Vitablocs Mark II miswak sticks had the highest ΔE00 values. Moreover, miswak mouthwash had the lowest ΔE00 values, with significant differences among groups. IPS e.max CAD miswak sticks had the highest mean values of compressive fracture. Vitablocs Mark II had the lowest values for mouthwash and toothpaste. Significant differences were found within the IPS e.max CAD group. Reparable fractures were found in IPS e.max CAD, while semi-reparable fractures were seen in other groups. CONCLUSIONS Most ΔE00 values were within the acceptable clinical range, with IPS e.max CAD showing superior color stability. The mouthwash group showed minimal ΔE00. IPS e.max CAD had the highest mean compressive fracture resistance values with reparable fracture types.

In vitro evaluation of the mechanical and optical properties of 3D printed vs CAD/CAM milled denture teeth materials.

This laboratory research aimed to assess the Flexural strength, fracture toughness, Volumetric wear and optical properties of various recent 3D-printed denture tooth materials and compare them to CAD/CAM milled materials. Four 3D-printed denture tooth materials (Lucitone Tooth, OnX, Flexcera Ultra +, and VarseoSmile Crown Plus) and one CAD/CAM milled denture teeth material (Ivotion Dent) were used to fabricate fifteen specimens for each material (with total no. of 300 specimens). Tests were conducted according to ISO standards to assess flexural strength, fracture toughness, color staining, and volumetric wear. All materials were printed, washed, cured, or milled following the manufacturer's instructions. Flexural strength and fracture toughness values were obtained by a universal testing machine. Volumetric wear was evaluated using a non-contact optical profilometer. Color stability outcomes were obtained via a spectrophotometer for determining L*a*b* values, with color change (ΔE2000) based on the CIEDE2000 formula. Data were analyzed using one-way ANOVA and Tukey post-hoc analysis (α = 0.05). All 3D-printed materials exhibited higher flexural strength values than the milled material (p < 0.05). For fracture toughness, two of the 3D-printed materials showed higher values than the milled material, while the other two had lower values. Insignificant variances in volumetric wear were detected between the materials (p > 0.05). Color staining results varied, with milled materials generally demonstrating better-staining resistance compared to the 3D-printed materials. 3D-printed denture tooth materials exhibit good mechanical and optical properties, presenting a cost-effective and efficient alternative to CAD/CAM milled materials for denture tooth fabrication.

Comparison of Tensile Bond Strength of Fixed-Fixed Versus Cantilever Single- and Double-Abutted Resin-Bonded Bridges Dental Prosthesis.

Resin-bonded fixed dental prostheses (RBFDP) are minimally invasive alternatives to traditional full-coverage fixed partial dentures as they rely on resin cements for retention. This study compared and evaluated the tensile bond strength of three different resin-bonded bridge designs, namely, three-unit fixed-fixed, two-unit cantilever single abutment, and three-unit cantilever double-abutted resin-bonded bridge. Furthermore, the study attempted to compare the tensile bond strengths of the Maryland and Rochette types of resin-bonded bridges. Based on the inclusion and exclusion criteria, a total of seventy-five extracted maxillary incisors were collected and later were mounted on the acrylic blocks. Three distinct resin-bonded metal frameworks were designed: three-unit fixed-fixed (n = 30), two-unit cantilever single abutment (n = 30), and a three-unit cantilever double abutment (n = 30). The main groups were further divided into two subgroups based on the retainer design such as Rochette and Maryland. The different prosthesis designs were cemented to the prepared teeth. Later, abutment preparations were made on all specimens keeping the preparation as minimally invasive and esthetic oriented. Impression of the preparations were made using polyvinyl siloxane impression material, followed by pouring cast using die stone. A U-shaped handle of 1.5 mm diameter sprue wax with a 3 mm hole in between was attached to the occlusal surface of each pattern. The wax patterns were sprued and cast in a cobalt-chromium alloy. The castings were cleaned by sandblasting, followed by finishing and polishing. Lastly, based on the study group, specimens for Rochette bridge were perforated to provide mechanical retention between resin cement and metal, whereas the remaining 15 specimens were sandblasted on the palatal side to provide mechanical retention (Maryland bridge). In order to evaluate the tensile bond strength, the specimens were subjected to tensile forces on a universal testing machine with a uniform crosshead speed. The fixed-fixed partial prosthesis proved superior to both cantilever designs, whereas the single abutment cantilever design showed the lowest tensile bond strength. Maryland bridges uniformly showed higher bond strengths across all framework designs. Within the limitations of this study, the three-unit fixed-fixed design and Maryland bridges had greater bond strengths, implying that they may demonstrate lower clinical failure than cantilever designs and Rochette bridges.

Assessment of Conventionally and Digitally Fabricated Complete Dentures: A Comprehensive Review.

CAD/CAM technology is gaining popularity and replacing archaic conventional procedures for fabricating dentures. CAD/CAM supports using a digital workflow reduce the number of visits, chair time, and laboratory time, making it attractive to patients. This study aimed to provide a comparative review of complete dentures manufactured using CAD/CAM and conventional methods. The PubMed/Medline, Science Direct, Cochrane, and Google Scholar databases were searched for studies published in English within the last 11 years (from 2011 to 2021). The keywords used were "computer-engineered complete dentures", "CAD/CAM complete dentures", "computer-aided engineering complete dentures", and "digital complete dentures". The search yielded 102 articles. Eighteen relevant articles were included in this review. Overall, computer-engineered complete dentures have several advantages over conventional dentures. Patients reported greater satisfaction with computer-engineered complete dentures (CECDs) due to better fit, reduced chair time, shorter appointments, and fewer post-insertion visits. CAD/CAM allows for precision and reproducibility with fewer procedures compared to conventional dentures. Polymethyl methacrylate is used as the denture base material for conventional dentures. For CECDs, the resin can be modified and cross-linked to improve its mechanical properties. The advantages of CECDs include a reduced number of appointments, saving chairside time, a digital workflow allowing easy reproducibility and greater patient satisfaction with a better fit.