Browsing by Author "Mohammed Gad"

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An Updated Review of Salivary pH Effects on Polymethyl Methacrylate (PMMA)-Based Removable Dental Prostheses
(2022) Alshahrani, Faris A.; Fatemah AlToraibily; Alzaid, Maryam; Amr A. Mahrous; Al Ghamdi, Maram A.; Gad, Mohammed M.
Salivary pH is a neglected factor that may affect the performance of removable dental prostheses (RDP). This study aimed to review literature in reference to the role of salivary pH on the performance of RDP and materials used for their fabrication. From January 1990 until December 2021, a search was done on PubMed, Scopus, and Web of Science databases using removable dental prostheses, salivary pH, PMMA, Denture base, and physical properties as keywords. Articles that met the inclusion criteria (full-length articles have investigated the effect of salivary pH on RDP materials in vitro and in vivo) were included. Out of 433 articles, 8 articles that met the inclusion criteria were included. All studies used artificial saliva with different salivary pH ranging between 3 and 14. Two articles investigated the role of salivary pH on the cytotoxicity of denture base resins and soft liner. One article studied the durability and retention of attachments, one article analyzed the performance of PEEK materials, one article researched the fatigue resistance of a denture base, one article investigated the corrosion of RPD framework cast and milled Co–Cr, one article studied the strength and clasp retention and deformation of acetal and PEEK materials, and one evaluated changes in mass and surface morphology of CAD–CAM fiber-reinforced composites for the prosthetic framework. Different salivary pH affected all included materials in this review except PEEK materials. The most adverse effect was reported with alkaline and acidic; however, the acidic showed the most deterioration effect. Salivary pH has a role in the selection of material used for RDP fabrication.
Antibiofilm Activity of 3D-Printed Nanocomposite Resin: Impact of ZrO2 Nanoparticles
(2023) Abdulrahman Khattar Alanzi; Alghafli, Jawad A.; Muheef, Mohammed A.; Husain muneer Mohammed Alshoalah; Al-Dubays, Mohammed A.; Mohammed Gad; Doaa AlEraky; Khan, Soban Q.; AlEraky, Doaa M.; Gad, Mohammed M.
Poly(methyl methacrylate) (PMMA) is a commonly used material, as it is biocompatible and relatively cheap. However, its mechanical properties and weak antibiofilm activity are major concerns. With the development of new technology, 3D-printed resins are emerging as replacements for PMMA. Few studies have investigated the antibiofilm activity of 3D-printed resins. Therefore, this study aimed to investigate the antibiofilm activity and surface roughness of a 3D-printed denture base resin modified with different concentrations of zirconium dioxide nanoparticles (ZrO2 NPs). A total of 60 resin disc specimens (15 × 2 mm) were fabricated and divided into six groups (n = 10). The groups comprised a heat-polymerized resin (PMMA) group, an unmodified 3D-printed resin (NextDent) group, and four 3D-printed resin groups that were modified with ZrO2 NPs at various concentrations (0.5 wt%, 1 wt%, 3 wt%, and 5 wt%). All specimens were polished using a conventional method and then placed in a thermocycler machine for 5000 cycles. Surface roughness (Ra, µm) was measured using a non-contact profilometer. The adhesion of Candida albicans (C. albicans) was measured using a fungal adhesion assay that consisted of a colony forming unit assay and a cell proliferation assay. The data were analyzed using Shapiro–Wilk and Kruskal–Wallis tests. A Mann–Whitney U test was used for pairwise comparison, and p-values of less than 0.05 were considered statistically significant. The lowest Ra value (0.88 ± 0.087 µm) was recorded for the PMMA group. In comparison to the PMMA group, the 3% ZrO2 NPs 3D-printed group showed a significant increase in Ra (p < 0.025). For the 3D-printed resins, significant differences were found between the groups with 0% vs. 3% ZrO2 NPs and 3% vs. 5% ZrO2 NPs (p < 0.025). The highest Ra value (0.96 ± 0.06 µm) was recorded for the 3% ZrO2 NPs group, and the lowest Ra values (0.91 ± 0.03 µm) were recorded for the 0.5% and 5% ZrO2 NPs groups. In terms of antifungal activity, the cell proliferation assay showed a significant decrease in the C. albicans count for the 0.5% ZrO2 NPs group when compared with PMMA and all other groups of 3D-printed resins. The group with the lowest concentration of ZrO2 NPs (0.5%) showed the lowest level of C. albicans adhesion of all the tested groups and showed the lowest Candida count (0.29 ± 0.03). The addition of ZrO2 NPs in low concentrations did not affect the surface roughness of the 3D-printed resins. These 3D-printed resins with low concentrations of nanocomposites could be used as possible materials for the prevention and treatment of denture stomatitis, due to their antibiofilm activities.
Denture Adhesive Utilization and Associated Factors among Dental Practitioners in the Eastern Province, Saudi Arabia
(2023) Gad, Mohammed M.; Almusallam, Mayyasah O.; Almarar, Fadak H.; Alhanoof K. Aldossary; Aldossary, Alhanoof K.; Nawaf A. Alghamdi; Yasser S. Alssaialiy; Nawaf I. Alghamdi; Alghamdi, Nawaf I.; Nazir, Muhammad A.
Background: Denture adhesives (DAs) enhance denture retention and stability, thus improving functions of removable prostheses. However, the adverse effects of DAs on denture foundation area were also reported. The clinical use of DAs among dentists has not been investigated in Saudi Arabia. Therefore, this study aimed to evaluate utilization of DAs and associated factors among dental practitioners in Saudi Arabia. Methods: This cross-sectional study included dental professionals practicing in both public and private sectors in the Eastern Province of Saudi Arabia. A self-administered pilot tested questionnaire was distributed among participants. The questionnaire has questions related to demographic information, knowledge and awareness, and the utilization of DAs. Bivariate and multiple logistic regression analyses were performed. Results: The study included 279 participants with a response rate of 79.03%. The majority of participants (61.6%) were below 35 years of age, males (56.6%), general dentists (57.3%), and worked in the private sector (59.9%). Less than half of the participants (39.4%) used DAs in their dental practice, and 64.5% recommended using DAs when needed. The most reported complications of DAs included inflammation (58.40%), ulcers (35.10%), and whitish color (31.20%) of denture foundation area. A vast majority (83.90%) reported that DAs improve retention of the dentures. About 55.2% of the participants were taught about DAs in their undergraduate programs, 12.5% attended continuing education, and 21.5% updated their knowledge about DAs. Multiple logistic regression showed that those who attended continuing education activities (adjusted OR = 2.41, p = 0.036) and updated their knowledge about DAs (adjusted OR = 4.43, p = < 0.001) were significantly more likely to use DAs in their dental practice. Conclusion: A minority of dental practitioners used DAs in their practices. Attending continuing education programs and updating knowledge of DAs were significantly associated with DAs utilization.
Denture care and oral health-related quality of life among complete denture wearers in Eastern Province of Saudi Arabia
(2023) Aljubran, Hussain; Hend Alshammary; Alamoudi, Marwah; Alramadan, Hassan; Nazir, Muhammad; Muhammad Nazir
Abstract Introduction This study aimed to evaluate denture care and hygiene and oral health-related quality of life (OHRQoL) among complete denture (CD) wearers in the Eastern Province of Saudi Arabia. Methodology This cross-sectional study was conducted on CD wearers in the Eastern Province of Saudi Arabia. A pre-tested questionnaire was administered among study participants. Questionnaire was divided in three sections: (1) patients' demographic data, (2) awareness and maintenance of CD and (3) OHRQoL. Independent sample t-test and one-way ANOVA test were performed. Results The study included data of 300 participants with 71% of males and 28% of females. Majority of participants (82.7%) cleaned CD daily, removed CD while sleeping (88.0%) and knew that unhygienic dentures can cause oral infection (92.7%). Only 19.3% used denture cleansing tables, 41% used toothpaste, and 60.7% rinsed CD with water. Regarding OHIP-DENT domains, highest score was for functional limitation domain (2.20 ± 1.67) and the lowest for handicap domain (0.94 ± 1.09). The mean OHIP-DENT score of the sample was 12.02 ± 8.52. Females (p = 0.006), participants below 65 years of age (p = 0.029), non-Saudis (p = 0.042), those with university education (p = 0.030) and low monthly income (p = 0.045) and participants who visited dentist due to problem with CD (p = 0.041) demonstrated significantly higher mean OHIP-DENT score. Conclusion Majority of participants demonstrated appropriate denture care behaviours because they were aware of the importance of denture care and hygiene. Female gender, age below 65 years, non-Saudi nationality, university education, low monthly income and visiting dentist due to problem were related to poor OHRQoL.
Effect of denture cleansers on the surface properties and color stability of 3D printed denture base materials
(2022) S. S. A. Alqanas, R. A.; Raghad Abdullah Alfuhaid; Sara Fayez Alghamdi; Gad, M. M.; Mohammed Gad
OBJECTIVES: To evaluate the effect of denture cleansers on surface roughness, hardness and color stability of 3D printed resins compared to heat-polymerized resin. METHODS: Acrylic specimens (N = 160) were prepared using one heat-polymerized (HP) and three 3D printed denture base resins. Specimens per material were randomly divided into four groups (n = 10) according to immersion solutions as follows: distilled water (DW), sodium hypochlorite (NaOCl), effervescent tablet 1 or effervescent tablet 2. Color changes (E) were measured using a spectrophotometer. Surface roughness (Ra, microm) and microhardness were evaluated. The results were analyzed using one- and three-way ANOVA with Tukey's post hoc test (alpha = 0.05). RESULTS: After 360 days of cleaning protocols, we observed a significant increase in the surface roughness of tested materials (P<0.001). Hardness values significantly decreased in all groups (P<0.001), except HP and ND specimens, cleaned with effervescent tablet 1 (P>0.05) and AS specimens with effervescent tablet 2 (P = 0.051). According to the National Bureau of Standards (NBS) score, all denture base specimens had 'perceivable' to 'extremely marked' color change after immersion in NaOCl, while immersion in effervescent tablets 1 and 2 resulted in a 'slight' to 'marked' color change. CONCLUSION: 3D printed denture bases exhibited changes in surface roughness, hardness and color similar to HP denture base material. The use of denture cleansers resulted in a time-dependent increase in surface roughness and a decrease in hardness. The color change was significant with NaOCl, while effervescent denture cleansers produced a minimal color difference. CLINICAL SIGNIFICANCE: Denture cleansers seem to influence surface properties over time. The degree of impact is mainly dependent on the type of cleanser selected, regardless of the type of denture base material.
Effect of Denture Disinfectants on the Mechanical Performance of 3D-Printed Denture Base Materials
(2023) Nora S. Alkaltham; Reem A. Aldhafiri; Al-Thobity, Ahmad M.; Soban Q. Khan; Aljubran, Hussain; Ijlal Shahrukh Ateeq; Khan, Soban Q.; Hussain Aljubran; Gad, Mohammed M.
Denture care and maintenance are necessary for both denture longevity and underlying tissue health. However, the effects of disinfectants on the strength of 3D-printed denture base resins are unclear. Herein, distilled water (DW), effervescent tablet, and sodium hypochlorite (NaOCl) immersion solutions were used to investigate the flexural properties and hardness of two 3D-printed resins (NextDent and FormLabs) compared with a heat-polymerized resin. The flexural strength and elastic modulus were investigated using the three-point bending test and Vickers hardness test before (baseline) immersion and 180 days after immersion. The data were analyzed using ANOVA and Tukey’s post hoc test (α = 0.05), and further verified by using electron microscopy and infrared spectroscopy. The flexural strength of all the materials decreased after solution immersion (p < 0.001). The effervescent tablet and NaOCl immersion reduced the flexural strength (p < 0.001), with the lowest values recorded with the NaOCl immersion. The elastic modulus did not significantly differ between the baseline and after the DW immersion (p > 0.05), but significantly decreased after the effervescent tablet and NaOCl immersion (p < 0.001). The hardness significantly decreased after immersion in all the solutions (p < 0.001). The immersion of the heat-polymerized and 3D-printed resins in the DW and disinfectant solutions decreased the flexural properties and hardness.
Fracture Load of 3D-Printed Interim Three-Unit Fixed Dental Prostheses: Impact of Printing Orientation and Post-Curing Time
(2023) Alkhateeb, Reem I.; Rand Baher AlDamanhori; Hadeel Saud AlGaoud; Rand Rasheed AlShubaili; Mohammed Gad; Gad, Mohammed M.
The fracture resistance of 3-unit interim fixed dental prostheses (IFDPs) fabricated using digital light processing (DLP) additive technology with different printing parameters is neglected. Therefore, this study investigates the effect of different printing orientations and different post-curing times on the fracture resistance of 3-unit IFDPs fabricated from two three-dimensional (3D) printed resins, NextDent, C&B (CB), ASIGA, and DentaTOOTH. A 3-unit dye was scanned, and an IFDP was designed. A total of 300 specimens (150/materials, n = 10) were printed and divided into three groups according to printing orientations (0°, 45°, 90°) per material. Each orientation was subdivided into five groups (n = 10) considering the post-curing time (green state as control, 30, 60, 90, and 120 min). All specimens underwent thermocycling (5000 cycles). Each specimen was fitted onto the die and loaded until fracture using a universal testing machine with a loading rate of 1 m/min. Data were analyzed using ANOVA and post hoc Tukey test (α = 0.05). The result showed that printing orientation had a significant effect on the fracture load for both ASIGA and NextDent materials (p < 0.05). The highest fracture load was recorded with 45° orientation, followed by 0° orientation and 90° orientation showed the lowest values per respective post-curing time. Post-curing time increased the fracture load (p < 0.05). Post-curing time had a positive effect on the fracture load. As the post-curing time increased, the fracture resistance load increased (p < 0.05), with 90 and 120 min showing the highest fracture load. The 0° and 45° printing orientations have a high fracture load for 3D-printed IFDPs, and an increased post-curing time is recommended.
Impact of international collaboration on dentistry related papers published in Kingdom of Saudi Arabia
(2023) Hend Alshammary; Marwah Alamoudi; Ajmal Khan, Muhammad; Soban Q. Khan; Muhammad Ajmal Khan; Alamoudi, Marwah; Jehan AlHumaid; AlHumaid, Jehan
Objective This bibliographic analysis was designed to review all dental publications in the Kingdom of Saudi Arabia (KSA) and evaluate the effect of international collaboration on the impact of published articles. Methods The Web of Science (WOS) database was used to extract all related published articles in the KSA from 1982 to 2021. The keywords were connected using Boolean Operators to download related articles. Downloaded articles were screened according to the following inclusion criteria: collaboration journal category, journal discipline, number of citations, number of authors, and impact factor. After applying the inclusion criteria and excluding single-author articles, 5,689 documents were included in the final analysis. The chi-square test and two-independent samples t-test were used to determine the statistical significance between the variables. Results A significantly higher proportion of articles with international collaboration (51.4%) were published in dental journals than those published nationally (43.3%) or within the institutional level (41.8%) (P < 0.0001). In addition, the average number of citations (9.28 ± 23.8) ranged from 0 to 749, received by an article and the impact factor of the journal in which the article was published, significantly higher in the case of internationally collaborative work compared with national or within institutional collaboration (P < 0.0001). Conclusion International collaboration positively affected the impact factor, number of citations, and quartile rank of published articles. Moreover, the number of co-authors in different countries contributes to the international collaboration effect.
Impact of ZrO2 nanoparticles addition on flexural properties of denture base resin with different thickness
(2021) S. A. A. Albasarah, H.Alaseef, N.al-Qarni, F. D.Akhtar, S.Khan, S. Q.Ateeq, I. S.Gad, M. M.; Hanan Al Abdulghani; Nawarah Alaseef; Faisal D. al-Qarni; Soban Q. Khan; Mohammed Gad; Ijlal Shahrukh Ateeq
PURPOSE. This study aimed to evaluate the effect of incorporating zirconium oxide nanoparticles (nano-ZrO2) in polymethylmethacrylate (PMMA) denture base resin on flexural properties at different material thicknesses. MATERIALS AND METHODS. Heat polymerized acrylic resin specimens (N = 120) were fabricated and divided into 4 groups according to denture base thickness (2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm). Each group was subdivided into 3 subgroups (n = 10) according to nano-ZrO2 concentration (0%, 2.5%, and 5%). Flexural strength and elastic modulus were evaluated using a three-point bending test. One-way ANOVA, Tukey's post hoc, and two-way ANOVA were used for data analysis (alpha = .05). Scanning electron microscopy (SEM) was used for fracture surface analysis and nanoparticles distributions. RESULTS. Groups with 0% nano-ZrO2 showed no significant difference in the flexural strength as thickness decreased (P = .153). The addition of nano-zirconia significantly increased the flexural strength (P < .001). The highest value was with 5% nano-ZrO2 and 2 mm-thickness (125.4 +/- 18.3 MPa), followed by 5% nano-ZrO2 and 1.5 mm-thickness (110.3 +/- 8.5 MPa). Moreover, the effect of various concentration levels on elastic modulus was statistically significant for 2 mm thickness (P = .001), but the combined effect of thickness and concentration on elastic modulus was insignificant (P = .10). CONCLUSION. Reinforcement of denture base material with nano-ZrO2 significantly increased flexural strength and modulus of elasticity. Reducing material thickness did not decrease flexural strength when nano-ZrO2 was incorporated. In clinical practice, when low thickness of denture base material is indicated, PMMA/nano-ZrO2 could be used with minimum acceptable thickness of 1.5 mm.
Influence of ZrO2 Nanoparticle Addition on the Optical Properties of Denture Base Materials Fabricated Using Additive Technologies
(2022) Abdulrahman Khattar Alanzi; Alsaif, Majed H.; Ibrajim Almindil; Alshaikh, Ali A.; Alsalem, Ali M.; Almindil, Ibrahim A.; Abdullah Mohammed Ahmed Al-Ajwad; Ali Musallam Alsalem; Ali Jaffar Ahmed Alboori; Almuhanna, Hussain M; Khan, Soban Q.; Soban Q. Khan; Gad, Mohammed M.
This study investigated the translucency of 3D-printed denture base resins modified with zirconium dioxide nanoparticles (ZrO2NPs) under thermal cycling. A total of 110 specimens were fabricated and divided into 3 groups according to the materials, i.e., heat-polymerized resin, and 3D-printed resins (NextDent, and ASIGA). The 3D-printed resins were modified with 0, 0.5, 1, 3, and 5 wt.% of ZrO2NPs. All the specimens were subjected to 5000 thermal cycles. The translucency was measured using a spectrophotometer. The results showed that the heat-polymerized resin had considerably higher translucency than the 3D-printed resins. Compared to the unmodified group, the translucency decreased significantly after adding 5% ZrO2NPs to NextDent and 3% ZrO2NPs to ASIGA resins. The highest translucency was achieved for NextDent by adding 0.5% ZrO2NPs and for ASIGA without any ZrO2NPs. It was found that the average concentration level in ASIGA was significantly higher than that in NextDent. These findings revealed that 3D-printed resins have lower translucency than heat-polymerized acrylic resin, and adding ZrO2NPs at low concentrations did not affect the translucency of the 3D-printed resins. Therefore, in terms of translucency, 3D-printed nanocomposite denture base resins could be considered for clinical applications when ZrO2NPs are added at low concentrations.
Polymethylmethacrylate Denture Base Layering as a New Approach for the Addition of Antifungal Agents
AlQahtani, Ghaida M.; AlSuhail, Haneen S.; Alqater, Norah K.; Sarah Abdulbaqui AlTaisan; Akhtar, Sultan; Khan, Soban Q.; Gad, Mohammed M.
Abstract Purpose To introduce a new technique, denture base layering, for the addition of titanium dioxide nanoparticles (TiO2NPs) to polymethylmethacrylate (PMMA) and to investigate the effects of the layering technique on Candida albicans (C. albicans) adhesion and on surface roughness, hardness, translucency, and flexural strength. Materials and methods In total, 210 heat-polymerized acrylic resin specimens were prepared as discs (15 × 2 mm) for testing C. albicans adhesion (n = 70) and surface roughness, hardness, and translucency (n = 70); and as acrylic plates (65 × 10 × 2.5 mm) for testing flexural strength (n = 70). Specimens were divided into 4 groups: control (n = 30), one-layer (n = 60), double-layer (n = 60), and dotted-layer (n = 60) according to the packing and layering technique. Each group was divided according to the concentration of TiO2NPs 1% and 2.5% (n = 10). The control group comprised one layer of unmodified resin. The one-layer group comprised one layer of a mixture of PMMA/TiO2NPs packed conventionally. The double-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a continuous thin layer of the PMMA/TiO2NPs mixture. Similarly, the dotted-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a thin layer of the PMMA/TiO2NPs. However, the second mixture was added in a dotted manner. The direct culture method for C. albicans adhesion before and after ultraviolet light activation, and surface roughness, hardness, translucency, and flexural strength were measured. An analysis of variance and Tukey's post hoc test were used for data analysis (α = 0.05). Results The addition of TiO2NPs reduced C. albicans adhesion (p ˂ 0.001). However, no significant difference was found between both concentrations within the same group before and after ultraviolet light activation (p > 0.05), except in the 1% dotted-layer (p = 0.022). Surface roughness and hardness were not affected by the additions of different concentrations of TiO2NPs (p = 0.905) and (p = 0.059), respectively. Translucency was significantly reduced in all the groups (p ˂ 0.001) except in the 1% dotted-layer (p = 0.332). Flexural strength decreased as the TiO2NPs concentration increased, with the greatest reduction in strength observed in the one-layer group (p ˂ 0.001). Conclusions The double and dotted layering techniques were effective in reducing C. albicans adhesion, without affecting surface roughness, hardness, or flexural strength. However, translucency was reduced in all the groups, except the 1% dotted-layer group.
The Effect of Salivary pH on the Flexural Strength and Surface Properties of CAD/CAM Denture Base Materials
(2022) Alzaid, Maryam; AlToraibily, Fatemah; al-Qarni, Faisal D.; Al-Thobity, Ahmad M.; Mohammed Gad; Ali, Saqib; Saqib Ali; Gad, Mohammed M.
Objectives This study aimed to evaluate the influence of different salivary pH on flexural strength, hardness, and surface roughness of computer-aided design and computer-aided manufacturing (CAD/CAM) milled and three-dimensional (3D)-printed denture base resins.Methods One heat-polymerized, two CAD/CAM milled (IvoCad, AvaDent), and two 3D-printed (FormLabs, NextDent) denture base resins were fabricated and divided into five groups (n = 10) according to the solutions: three groups were immersed in different salivary pH (5.7, 7.0, or 8.3), one group was immersed in distilled water (DW) as a positive control, and one group had no immersion (negative control). All immersions were performed at 37°C for 90 days. Flexural strength, hardness, and surface roughness were measured before and after immersion. Data was analyzed with analysis of variance and post hoc Tukey's test (α = 0.05).Results After immersion, all specimens had lower flexural strength values when compared with those with no immersion. Comparing the immersion groups, the highest flexural strength value (93.96 ± 3.18 MPa) was recorded with IvoCad after immersion in DW while the lowest value (60.43 ± 2.66 MPa) was recorded with NextDent after being immersed in 7.0 pH saliva. All specimens had significant decrease in hardness except IvoCad and AvaDent specimens where both presented the highest surface hardness (53.76 ± 1.60 Vickers hardness number [VHN]) after immersion in DW while NextDent showed the lowest hardness value (24.91 ± 2.13 VHN) after being immersed in 8.3 pH saliva. There was statistically significant difference between the baseline and different artificial salivary pH solutions in terms of surfaces roughness, with the highest surface roughness were found in 3D-printed resin materials.Conclusion After exposure to artificial saliva with different salivary pH, the milled CAD/CAM denture base resins showed higher flexural strength, hardness, and lesser surface roughness than conventional and 3D-printed denture base resins.
The Toothbrushing Effects on Surface Properties and Color Stability of CAD/CAM and Pressable Ceramic Fixed Restorations—An In Vitro Study
(2023) Mahrous, Amr A.; Ahmed Alkadi; Alqahtani, Faisal; Aljar, Yousif; Mohammed Gad; Taymour, Noha; Alotaibi, Abdulkareem; Amr A. Mahrous; Gad, Mohammed M.
Pressable ceramic restorations have been introduced and investigated, and found comparable to CAD/CAM ceramic in terms of mechanical properties; however, the effect of toothbrushing on the pressable ceramic has not been thoroughly investigated. The objective of the current study was to assess the effect of artificial toothbrushing simulation on the surface roughness, microhardness, and color stability of different ceramic materials. Three lithium disilicate-based ceramics (IPS Emax CAD [EC], IPS Emax Press [EP]; (Ivoclar Vivadent AG), and LiSi Press [LP] (GC Corp, Tokyo, Japan)) were examined. For each ceramic material, eight bar-shaped specimens were prepared and subjected to 10,000 brushing cycles. Surface roughness, microhardness, and color stability (∆E) were measured before and after brushing. Scanning electron microscopy (SEM) was used for surface profile analysis. The results were analyzed using one-way ANOVA, Tukey’s post hoc test, and paired sample t-test α = 0.05. The findings revealed a non-significant decrease in the surface roughness of EC, EP, and LP groups (p > 0.05), and both LP and EP have the lowest surface roughness values (0.64 ± 0.13, 0.64 ± 0.08 µm) after brushing, respectively. Toothbrushing showed a decrease in the microhardness of the three groups: EC and LP, p < 0.001; EP, p = 0.012). EP showed the lowest hardness value after brushing (862.45 ± 273.83). No significant changes (∆E) were observed in all groups (p > 0.05); however, the EC group was found to be considerably affected by color changes, in comparison to the EC and LP groups. Toothbrushing had no effect on surface roughness and color stability of all tested materials, but it decreased the microhardness. Material type, surface treatments, and glazing of ceramic materials contributed to the surface changes in the ceramic materials, necessitating further investigations in terms of the toothbrushing effect with different glazing as variables.
Water Sorption, Solubility, and Translucency of 3D-Printed Denture Base Resins
(2022) Saleh Zaher Alshehri; Alhamid, Shahad A.; Albarrak, Alanoud; Soban Q. Khan; Mohammed Gad; Alqarawi, Firas K.; Faris Alshahrani
Wear and Fracture Resistance of 3D-Printed Denture Teeth: An In Vitro Comparative Study
Rahaf Fahad Alghamdi; Alghamdi, Rahaf; Al-Ghamdi, Raghad; Faisal D. al-Qarni; Akhtar, Sultan; Khan, Soban Qadir; Alalawi, Haidar; al-Qarni, Faisal D.
Abstract Purpose The longevity of removable prostheses is mostly influenced by the properties of the used materials. The ability of the material to withstand high occlusal loads without deformation can enhance patient satisfaction and quality of life. This in vitro study aimed to investigate the wear and fracture resistance of three-dimensional (3D)-printed teeth compared with commercially available acrylic resin teeth. Materials and methods A total of 40 prefabricated acrylic teeth and 40 3D-printed teeth were prepared in two forms: anatomical for fracture resistance or flat for wear resistance (n = 10). For wear evaluation, specimens were scanned at baseline and then subjected to thermal cycling (10,000 cycles). This was followed by a chewing simulator (60,000 cycles) against either metal or natural tooth. Then, the specimens were scanned again. Wear analysis was performed by superimposing the standard tessellation language (STL) files from baseline and the final scans with the aid of GOM Inspect 2020 software. Fracture resistance was assessed with a universal testing machine at a crosshead speed of 0.5 mm/min before and after thermal cycling. Data were analyzed with two-independent t-test and two-way ANOVA (α = 0.05). Results The 3D-printed teeth showed significantly lower wear resistance than the prefabricated ones with both antagonists (metal, p = 0.049; natural tooth, p = 0.021). The fracture resistance of the 3D-printed teeth was significantly higher than that of the prefabricated teeth before thermocycling (p = 0.042). After thermal cycling, the fracture resistance of both groups was decreased with no significant differences between them (p = 0.266). Conclusions The 3D-printed teeth showed lower wear resistance and higher fracture resistance than the prefabricated ones. Thermal cycling negatively affected the fracture resistance of 3D-printed teeth.