Comparison of color changes, fracture strengths, and failure modes of conventional endocrowns and endocrowns with different design modifications.

BACKGROUND: Endocrowns (ECs) are alternatives for rebuilding severely damaged teeth and show superior efficacy in molars over premolars. OBJECTIVE: The objective of this in vitro study is to evaluate the effects of different preparation designs with short pulp chambers on the mean color change (Δ⁢E), fracture resistance, and failure types of mandibular molar ECs. METHOD: A total of 40 extracted mandibular molars were treated endodontically and divided into four groups. Samples in groups 1, 2, 3, and 4 had occlusal preparation depths of 5 mm, 3 mm, 3 mm with ferrule, and 3 mm with boxes, respectively. The samples were immersed in coffee and their Δ⁢E values were measured by using the Commission Internationale de l'Eclairage color system. They were also subjected to a fracture test. Next, all specimens were examined visually under a stereomicroscope to evaluate their failure modes and identify their fracture origins. Data were entered and analyzed by using Statistical Package for Social Sciences. RESULTS: Among all groups, group 4 (3 mm + boxes) presented the highest Δ⁢E (4.15) after immersion in coffee. Moreover, ANOVA revealed that the Δ⁢E of group 4 (occlusal preparation depth of 3 mm with boxes) was significantly different (p< 0.05) from that of group 2 (3 mm + ferrule, 3.07). The EC with a 3 mm chamfer and ferrule showed the highest maximum load of 2847.68 ± 693.27 N, whereas that with a 5 mm chamfer finish line had a marginally reduced load at fracture of 2831.52 ± 881.83 N. The EC with a 3 mm chamber and boxes had a slightly increased maximum load of 2700.75 ± 436.40 N, whereas that with the 3 mm chamber had the lowest maximum load at fracture of 2385.97 ± 465.61 N. One-way ANOVA showed that different EC preparation designs had no effect on maximum fracture load (F [3,16] = 0.550, p= 0.6). CONCLUSION: The recorded Δ⁢E values of ECs in all groups were equal or marginally higher than the acceptable values. The EC with a 3 mm chamfer and ferrule displayed the highest mean maximum load. The EC with a 5 mm chamfer finish line had a marginally lower maximum load at fracture than other ECs. Failures, such as ceramic fracture, split fracture, and ceramic and tooth splitting above the cemento-enamel junction (CEJ) or vertically were predominant in samples with occlusal preparation depths of 3 mm with ferrule and 5 mm.

Radiographic Assessment of 121 Glass Fiber Post Procedures in 32 Patients Aged 21-60 Years Performed by 6th-Year Dental Students During the 2022-2023 Academic Year at the College of Dentistry, Jazan University, Saudi Arabia.

BACKGROUND The restoration of endodontically treated teeth (ETT) and severely damaged teeth has been a concern of clinicians. Glass Fiber Post (GFPs) combine the strength of carbon fiber posts with the esthetic appearance of glass to resemble natural dentin during dental restoration procedures. This radiographical study assessed the GFP carried out by students enrolled in the Clinical Comprehensive Course at the College of Dentistry, Jazan University. MATERIAL AND METHODS A total of 32 patients treated by 18 6th-year dental students with 121 GFPs were assessed in this cross-sectional radiographic study. The assessment covered tooth type, arch, post-to-root width, length of post in relation to the crown and root lengths, amount of remaining gutta percha (GP), and gap between GP and post. Data were analyzed using SPSS, and associations between variables were determined using the chi-square test. RESULTS Maxillary teeth were the most frequently restored with posts (88.4%) with most being (58.7%) anterior teeth, and 50.4% of posts had widths that were one-third that of the root. The percentage of posts was twice (71.1%) or equal to (26.4%) the crown length, whereas two-thirds of the tested GFPs were >5 mm of the remaining GP. Significant differences were observed in location and position of teeth with post width, post length in relation to crown or root length, and amount of remaining GP, with P values of 0.018, 0.000, and 0.001, respectively. CONCLUSIONS The assessed radiographs revealed that the performance of sixth year students in accomplishment GFP radiographically was satisfactory and within the values recommended in the literature.

Comparative Evaluation of Hardness and Energy Absorption of Some Commercially Available Chairside Silicone-Based Soft Denture Liners and a Heat-Cured Soft Denture Liner.

Aim: To investigate the hardness and energy absorption of four commercially available chairside types of silicone materials and compare their properties with heat-cured silicone material. Materials: The chairside materials investigated were GC reline soft, mucopren soft, sofreliner soft and elite soft relining. The heat-cured polymer silicone material was Molloplast B. All soft lining materials were processed according to manufacturers' instructions. Two properties were investigated. Ten specimens for each test were prepared for each soft liner except for the water absorption and solubility test, for which only five specimens were prepared. The specimens of energy absorption (10 × 10 × 3 mm) were tested using a Lloyd instruments testing machine. Hardness specimens (38 × 38 × 3) were tested using a shore A durometer and were divided into two subgroups; dry and wet storage. Results: The specimens of energy absorption (10 × 10 × 3 mm) were tested using a Lloyd instruments testing machine. Sofreliner soft was significantly softer than Molloplast B. GC reline soft was significantly harder than molloplast B. At high loads, sofreliner soft and elite soft relining was significantly more resilient than molloplast B. Mucopren soft was significantly stiffer than Molloplast B. At low loads, all materials showed similarities in stiffness and resilience; the difference between them was insignificant. After one month of immersion, GC reline and mucopren significantly increased hardness values. Conclusion: In all conditions and at all four-time points, the hardness values for GC Reline soft were the greatest, and hardness values for Sofreliner Soft were the least. Some chairside soft denture lining materials could have similar significant properties to molloplast-B, such as sofreliner soft and elite.

Comparative Analysis of Properties in Chairside Silicone Denture Liners versus Heat-Cured Molloplast-B: An In-Depth In Vitro Evaluation.

BACKGROUND We investigated the bond strength, tensile strength, and water absorption properties of 4 widely used chairside silicone long-term denture soft lining materials and compared properties with those of heat-cured silicone material. MATERIAL AND METHODS Four chairside materials (GC Reline Soft, Mucopren Soft, Sofreliner Soft, and Elite Soft Relining) and a heat-cured silicone material (Molloplast B) were investigated. For tensile and shear bond strength and tensile strength, samples were prepared according to the manufacturers' instructions and the testing machine used. For water absorption, IOS 1567 was followed to prepare specimens. Bond strengths were measured using a Lloyd Instruments materials testing machine. Ten specimens for each test were prepared for each soft liner, except for water absorption and solubility tests, for which only 5 specimens were prepared. ANOVA, Bonferroni, and Kruskal-Wallis tests were used to compare values of materials and assess changes over time. RESULTS There was strong evidence of differences in the properties between materials. GC Reline Soft showed comparable tensile bond (1.4±0.6 MPa), shear bond (1.1±0.4 MPa), tensile strength (5.44±0.98), water absorption (0.92±0.2 µg/mm³), and solubility values (0.3±0.2 µg/mm3) to that of Molloplast B (1.4±0.4; 1.6±0.5; 4.53±0.9 MPa, 1.7±0.3, and 1.0±0.3 µg/mm³, respectively). The water solubility of Sofreliner Soft was significantly lower (1.5±0.8 µg/mm³) than that of Molloplast B. CONCLUSIONS There were significant differences between some properties of 4 chairside denture soft lining materials and that of Molloplast B, which had higher shear and tensile bond strength than chairside denture silicone soft lining materials but had the highest water solubility.

Unlocking Endocrown Restoration Expertise Among Dentists: Insights from a Multi-Center Cross-Sectional Study.

BACKGROUND This study, employing an online questionnaire, aimed to assess and contrast the awareness, knowledge, and perceptions of dentists in Saudi Arabia (SA) regarding endocrowns (EC) as post-endodontic restorations with those of dentists educated in various other countries. MATERIAL AND METHODS We conducted a cross-sectional survey among dental interns and practicing dentists in government facilities, private dental centers, and dental colleges in SA, including participants of diverse nationalities. We disseminated validated, closed-ended questionnaires through WhatsApp via Google Forms. The Chi-square test was applied to assess associations between categorical variables, with a P-value of ≤0.05 indicating statistical significance. RESULTS The majority of participants (61.2%) indicated that EC restorations are best suited for molar teeth. Furthermore, 69.6% asserted that the primary objective of employing EC is to accomplish minimally invasive preparations while preserving the existing tooth structure. Among the responses, 68.3% pinpointed debonding of ECs as a significant cause of failure. Notably, substantial differences were observed in responses concerning the knowledge or practice of EC across various factors such as gender, educational attainment, country of graduation, and workplace. CONCLUSIONS The findings reveal a comparatively low adoption of ECs among the participants, irrespective of experience or country of education. This underscores the need for incorporating ECs into dental curricula through theoretical and clinical discussions or considering them as a subject for post-graduate continuing education programs.

Dimensional Stability of Light-Activated Urethane Dimethacrylate Denture Base Resins.

An accurate and dimensionally stable trial denture base is required for a successful denture. The aim of this in vitro study was to assess the dimensional stability of a light-activated urethane dimethacrylate (UDMA) visible light cure (VLC) denture base with three fabrication techniques and different curing cycles. Forty-five VLC denture base samples were divided evenly into three groups. Group A used a conventional fabrication technique with a curing cycle of 5 min. Group B used a modified fabrication technique with two 4-min curing cycles. Group C used a multi-step fabrication technique with three curing cycles (4 min, plus 4 min, plus 2 min). The samples were sectioned and observed under a stereomicroscope to measure the discrepancy between the sample and the master cast. The mean dimensional discrepancy (mm) at the molar region at mid-palate, after 24 h in Group A, B and C was 0.790 mm, 0.741 mm and 0.379 mm, respectively; at the right ridge crest, it was 0.567, 0.408 and 0.185, while at the left ridge crest it was 0.475, 0.331 and 0.125, respectively. Statistical analysis showed significantly different dimensional discrepancies among the groups at all three sites; right ridge crest (F = 93.54, p < 0.001), left ridge crest (F = 105.96, p < 0.001) and mid-palate (F = 125.53, p < 0.001). Within the limitations of this laboratory study, it can be concluded that the denture base using a multi-step fabrication technique with three curing cycles provides better adaptation than the conventional technique. The significance of the study is that clinicians should consider performing denture base fabrication using a multi-step technique to enhance adaptation and hence the stability of the dentures for patients.

Physical, Optical, and Mechanical Properties of Ceramic Materials after Coffee Immersion and Evaluation of Cleaning Impact with Different Oral Hygiene Tools.

This study aimed to evaluate the effect of three oral hygiene tools, a regular toothbrush, an electronic toothbrush, and mouthwash, on the color stability of three different computer-aided design (CAD) and computer-aided manufactured (CAM) ceramic blocks. Feldspathic ceramic (Vita Triluxe Forte), hybrid resin ceramic (Vita Enamic), and lithium disilicate glass-ceramic (IPS e.max CAD) were used in this study. A CAD/CAM system and 81 (27 of each material) samples of ceramic blocks were used. All samples were immersed in black coffee for 15 days, and the coffee was changed twice per day. Using a spectrophotometer probe, samples on a grey background were scanned, and physical properties like surface hardness and depth were measured using interferometry and a 3D non-contact surface metrology. After 30 days of application of oral hygiene tools, instruments were used to measure various physical, mechanical, and optical properties. Vita Triluxe had the highest average color variation values (ΔE00) after 15 and 30 days of immersion in coffee in both regular and electronic toothbrushes. Moreover, IPS e.max CAD had the least ΔE00 values with no significant differences among the groups. The surface roughness (Ra) of the Vita Enamic ceramic increased when using a regular toothbrush, and the surface height (Rz) for the Vita Enamic ceramic increased when an electronic toothbrush was used. IPS e.max CAD had the greatest modules of elasticity forces, and Vita Triluxe Forte had the lowest when used with a regular toothbrush. The ΔE00 values of the tested materials were minimally increased or decreased after 30 days of cleaning, and all were clinically acceptable. Ra and Rz were the highest for Vita Enamic in comparison to the other groups. The highest percentage in IPS e.max CAD was associated with a type 1 fracture, whereas type 3 was predominantly observed with Vita Enamic, and type 2 in the Vita Triluxe group without significant differences.

Osseo-densification versus conventional surgical technique in low density jaw bone: A split mouth in vivo study.

BACKGROUND: The success of dental implants depend on implant design, surgical technique, bone density, implant morphology and postoperative care. Initial stability is utmost importance and is of concern in low density bone. The osseo-densification strategy enhance primary stability by raising density of the osteotomy site walls by non-subtractive drilling, unlike conventional technique. OBJECTIVE: The aim of this in vivo study was to assess and compare the osseo-densification implant drilling technique with conventional implant drilling in terms of primary implant stability along with other factors, plaque index, bleeding on probe, pocket depth and radiographic assessment of bone density, marginal bone loss using CBCT. METHOD: A total of 20 patients aged between 40 and 59 years were included in this research. A split-mouth configuration of 40 implants was used. In the osseo-densification group, specialized (Densah) bur kit was used to insert 20 implants on one side. In the conventional group, standard bur kit was used to insert 20 implants on the opposite side of the jaw. For each patient, clinical and radiographic assessment was performed at regular intervals at the beginning (immediately after surgery), seven months, and a year following surgery. RESULTS: With the exception of bone density, which was statistically significant in favour of the osseo-densification group immediately after surgery, primary and secondary stability, plaque index, bleeding on probe, pocket depth and even marginal bone loss were not significantly different between the two groups in this investigation. CONCLUSION: Osseo-densification technique provided a better primary stability in the low density bone cases thus, can be consider as a trustworthy treatment for speeding up the healing process while also maintaining marginal bone integrity following loading. Use of specialized bur while drilling procedure improves the density around the implants.

Assessment of Color Stainability of Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) Ceramic Materials After Hot and Cold Coffee Immersion at Different Time Intervals.

BACKGROUND This spectrophotometric study assessed the color stability of CAD/CAM restorative materials with different exposed surfaces following staining by hot Arabic Qahwa and cold coffee. MATERIAL AND METHODS Ninety-six specimens were fabricated from 3 different CAD/CAM ceramic materials: Vita Suprinity (Vita-S), Vita Enamic (Vita-E), and Vitablocs Mark II (Vitablocs-MII). We divided 32 specimens for each group into glazed or polished surfaces, with 16 specimens in each group, then subdivided them according to staining materials: Arabic Qahwa and Frappuccino Cold Coffee. Color of specimens was measured during immersion in staining materials (BEFORE) as baseline with (Vita classic) and (L, a, b), for average color changes (ΔE00), then remeasured after 2, 4, and 12 weeks, and described as 1st, 2nd, and 3rd measurements for VITAPAN Classic shade and T1, T2, and T3 for ΔE00 values using the CIE L*a*b* equation. We performed ANOVA and then post hoc testing. RESULTS We found significant differences in ΔE00 values during immersing in hot Arabic Qahwa and cold coffee for tested materials in glazed or polished specimens. Polished specimens of Vita-S and Vita-E had the highest color changing and staining compared to glazed surfaces. Vitablocs-MII had the best color stability through immersion periods. Moreover, there were changes in relation to VITAPAN Classic shade guide for both Vita-S and Vita-E specimens during different immersion periods. CONCLUSIONS Coffee caused staining and contamination of ceramic material. Values of ΔE00 for tested ceramic materials were significantly different but were within the clinically acceptable range. Polished specimens showed higher staining; therefore, we highly recommend re-glazing of ceramic restorations to maintain color stability.

Surface roughness and color measurements of glazed or polished hybrid, feldspathic, and Zirconia CAD/CAM restorative materials after hot and cold coffee immersion.

BACKGROUND: The purpose of this study evaluates and compares the effect of surface roughness (Ra) and color stability on computer-aided design/computer-aided manufacturing (CAD/CAM) hybrid resin (Vita Enamic), feldspathic (Vitablocs® Mark II), and lithium disilicate Zirconia (Vita Suprinity) glazed or polished ceramics immersed in hot Arabic Qahwa and cold coffee. METHODS: A total of 96 standardized samples were prepared from CAD/CAM restorative materials. Half of the samples were polished as per the manufacturer's instructions using a porcelain polishing kit, and the other half were glazed. Samples were distributed and immersed in hot Arabian Qahwa and cold coffee followed by thermocycling. Ra measurements and color changes were conducted before and after immersion. SEM images were captured from each type of glazed or polished ceramic. One-way ANOVA paired Student's t-test, and Bonferroni test were conducted to detect significant difference between the groups. P > 0.05 was a significant level. RESULTS: Of all the tested samples, Ra increased without any significant difference; however, mean color changes (ΔE*) showed significant differences. An increase in Ra was noted for all the glazed and polished samples after immersion and thermocycling. However, differences were significant only in VM II. In addition, ΔE* was significant only in Vita Suprinity (VS) samples. For immersion groups, significant Ra changes were noticed in glazed samples, only in Vita Enamic (VE) with no ΔE*. In polished samples, mean Ra changes were observed in VM II and VS samples. Significant differences were also noticed in polished VE and VS subgroups of ΔE*. CONCLUSIONS: Ra affects all the tested samples, providing higher values on the polished specimens. The ΔE* caused by hot Arabic Qahwa and cold coffee on glazed or polished CAD/CAM restorative materials were clinically acceptable.

Dental Anxiety and Fear among Patients in Jazan, Kingdom of Saudi Arabia: A Cross-sectional Study.

AIM: The current study aims to address the patient's dental anxiety (DA) And dental fear (DF) under the treatment of a general practitioner (GP) among different parameters. MATERIALS AND METHODS: The cross-sectional study included 500 patients recruited from different clinics in Jazan, Saudi Arabia. Data were collected through a questionnaire-based form consisting of three parts; the first part was personal and demographic questions whereas the second and third parts were a modified dental anxiety scale (MDAS) and a dental fear survey (DFS) to measure DA and DF among patients. Spearman's correlation was used to measure the relation between DA and DF as well as Chi-square tests and logistic regression analyses for analyzing the effect of each variable on DA and DF. RESULTS: All patients fulfilled their eligibility criteria. A high percentage was found in moderate anxiety (36.8%) as well as in moderate fear (46.2%) among different anxiety and fear scales. The association between DA and DF was positively significant (p <0.01). There was a significant effect of gender, age, education, khat use, marital status, monthly income, and type of clinic on patients' DA and DF. CONCLUSIONS: There is a positive relation between MDAS and DFS, thus the DA affects the DF. Female patients had a lower DA and DF than male patients. Furthermore, the government clinics had the highest DA and DF prevalence levels for patients. Moreover, the high school-graduated patients seem to have a high DA and DF vs other patient educational levels. CLINICAL SIGNIFICANCE: It would be beneficial to include an educational training program about psychological patient management in the study curriculum as well as to be offered as a special course to newly graduated dentists. This modification will aid to improve the GPs to get rid of DA and DF patients. How to cite this article: AlDhelai TA, Al-Ahmari MM, Adawi HA, et al. Dental Anxiety and Fear among Patients in Jazan, Kingdom of Saudi Arabia: A Cross-sectional Study. J Contemp Dent Pract 2021;22(5):549-556.

Computerized occlusal forces analysis in complete dentures fabricated by additive and subtractive techniques.

BACKGROUND: Fabrication of complete dentures by computer-aided designing and computer-aided manufacturing (CAD-CAM) techniques are now common. Subtractive and Additive are the two principal CAD-CAM techniques used for this purpose. However, studies that evaluated the occlusal forces by CDs manufactured by these techniques are lacking. OBJECTIVES: To compare the occlusal forces in complete dentures fabricated by additive, subtractive and conventional techniques with different occlusal schemes, using computerized occlusal force analysis system [Tech-Scan III (T-Scan III)]. METHODS: Three groups (Gr) were made on the basis of techniques of fabrication of CDs: Conventional CDs (CCD), Subtractive CDs (SCD), and Additive CDs (ACD). Each group CDs were further divided into three sub groups based on occlusion schemes: bilateral balanced occlusion (BBO), lingualized occlusion (LO) and mono plane occlusion (MO). A total of 45 CDs were made: 15 in each group with 5 CDs of each occlusal scheme. For all samples, occlusal force analysis (percentage of occlusal force applied on the right and left sides of the arch, centralization of forces and percentage of maximum occlusal force) was done using computerized occlusal analysis system: T-Scan III. Univariate regression analysis and logistic regression analysis were used to find the effects of the technique of fabrication and occlusion scheme over the occlusal forces (p< 0.05). RESULTS: The intergroup comparison revealed statistically significant differences (p< 0.01) in right-left side force difference, maximum bite force in CDs fabricated by various techniques and with different occlusion schemes. Though the effect of occlusion scheme was more than the technique of fabrication (according to effect size estimation). The maximum force difference between right-left side was observed in combination of CCD technique and MO scheme (36.88 ± 2.82 N). Furthermore, the maximum bite force was observed for SCD technique (89.14 ± 6.08 N) and LO scheme (92.17 ± 3.22 N). In comparison to ACD, the chances of centre of force out of ellipse was 2.53 time more in CCS and 0.75 times less in SCD techniques and in comparison to MO, the chances of out of ellipse was 0.298 times less in BBO and 0.396 times less in LO schemes, though these chances were not statistically significant (p> 0.05). CONCLUSIONS: The digital CDs fabricated by subtractive technique were proved to be superior to additive technique in terms of occlusal force analysis on tested parameters. However, further research is needed on patients to determine the exact superiority of one technique over the other.

Clinical analysis of CAD-CAM milled and printed complete dentures using computerized occlusal force analyser.

BACKGROUND: Digital complete dentures (CDs) by computer-aided designing and computer-aided manufacturing (CAD-CAM) techniques (milling and three-dimensional (3-D) printing) have been evaluated clinically and provided satisfactory results. But clinical studies assessing occlusal forces by digital dentures are lacking. OBJECTIVES: To compare the occlusal force parameters in complete dentures (CDs) fabricated by milling, 3-D printing and conventional techniques having 3 commonly used occlusal schemes, using computerized occlusal force analysis system (Tech-Scan III- T-Scan III). METHODS: A total of 45 CDs were fabricated for 5 patients. Nine sets of CDs were made for each patient and were divided into 3 groups: Conventional CDs (CCD), Milled CDs (MCD), and 3-D printed CDs (3-DP CD). The CDs in each group were further divided into 3 sub-groups based on occlusion schemes - bilateral balanced (BBO), lingualized (LO) and mono plane (MP). Occlusal force analysis [percentage (%) of occlusal force applied on the right and left sides of the arch difference between them, centralization of forces and % of maximum occlusal/bite force] was done using computerized occlusal analysis system (T-Scan III) at the time of denture insertion. Univariate regression analysis and logistic regression analysis were performed (p< 0.05). RESULTS: The intergroup comparison of force distribution on right and left side in CDs fabricated by various techniques showed insignificant differences (p> 0.05) but statistically significant differences (p< 0.01) were found in right-left side force difference, maximum bite force % and centralization of forces. The maximum force difference on right and left side was observed CCD with MO (37.48 ± 1.03 N) and maximum occlusal-bite force % was observed for 3-DPCD with LO (95.40 ± 1.30 N). In comparison to 3-DP CD, the chances of centre of force out of ellipse (centralization of forces) was 3.36 and 2.15 times more in CCD and MCD techniques made CDs respectively. CONCLUSIONS: The occlusal parameters in CDs were affected by the fabrication techniques and occlusal schemes of CDs. The digital CDs retain adjusted occlusal schemes better and 3-DP CDs with BBO and LO occlusal schemes provided centralization of forces, better distribution and high maximum occlusal force % respectively.

Influence of the Coca-Cola Drinks on the Overall Color of Glazed or Polished Porcelain Veneers Fabricated from Different Materials and Thicknesses: An In Vitro Study.

AIM: The aim of the current study is to assess the influence of Coca-Cola drinks on the overall color of glazed or polished porcelain veneers fabricated of three different porcelain systems and two different thicknesses. MATERIALS AND METHODS: A total of 96 ceramic disk specimens were fabricated. The ceramic veneers were prepared to a standardized thickness of 1.0 mm ± 0.025 mm and 0.6 ± 0.025 (48 samples each group) using the following ceramic systems: Zircon, E-max press, and E-max CAD/CAM. Veneer samples from each system were divided into two subgroups (n = 8). First subgroup samples were glazed according to the manufacturer's instructions, and the other subgroup samples were adjusted with diamond burs then polished with ceramic polishing kit. Color was measured with Vita Easyshade spectrophotometer. Then all samples immersed with Cola drink, for 4 weeks, in a thermocycling machine and then the color were measured again and color change was recorded. RESULTS: Significant differences in color change were noticed before and after immersing with Coca-Cola and thermocycling for all materials and thicknesses used (p < 0.01). Significant differences in color changes were noticed between glazed and polished samples (p < 0.001). No significant differences in color change were noticed when using different thicknesses for all materials used (p < 0.05). CONCLUSION: Different porcelain materials have shown significant color changes after immersing and thermocycling in Coca-Cola drinks. The color changes of polished porcelain specimens were more considerable than those of polished specimens for all porcelain materials and thicknesses used. This suggests reglazing of all esthetic restoration after any adjustments might be performed and before final cementation in an attempt to maintain the color stability in oral environment. CLINICAL SIGNIFICANCE: To achieve a perfect color stability of ceramic veneers, clinicians should take into consideration the possible color deviations that might result after any adjustment followed by polishing procedures to the ceramic surface. And, it is always preferable to do reglazing of porcelain restorations after any surface treatments and before final cementation.

Khat Chewing Induces a Floral Shift in Dental Material-Associated Microbiota: A Preliminary Study.

BACKGROUND The habit of khat (Catha Edulis Forskal) chewing is widely practiced in the southern regions of Saudi Arabia, Yemen, and East Africa. This social habit has tremendous effects on oral and general health of khat chewers. Khat may affect bacterial species in plaque biofilms on oral rehabilitation materials. This preliminary case-controlled study aimed to assess and compare the effect of khat chewing on bacterial biodiversity between non-khat chewers (NKC) and khat chewers (KC) in oral biofilms on oral rehabilitation materials using polymerase chain reaction (PCR). MATERIAL AND METHODS Fifty participants were organized into 2 equal groups of NKC and KC, each containing 5 subgroups related to filling material type. Some participants had amalgam (A) or composite (C) restorations, while others had feldspathic porcelain (FP), nickel chromium (NC), and zirconia ceramic (ZC) crowns or bridges. Oral biofilm samples were collected from all participants, DNA was extracted, and samples were subjected to PCR. Bacterial species were then identified and counted. PCR products were sequenced to detect similarity. Partial 16S rRNA gene sequences of the current study samples were compared with 16S rRNA gene sequences from GenBank using BLAST on the National Center for Biotechnology Information website. RESULTS The Streptococcus sp. was the most common bacterial species among our participants (40; 80%), followed by Lactobacillus and Veillonella spp., accounting for 12% (6) and 8% (4), respectively. Streptococcus sp. was observed equally among NKC and KC, but Lactobacillus and Veillonella spp. were higher in KC and NKC, respectively. Lactobacillus was associated mainly with prosthetic materials, and Streptococcus was found among all examined dental restorative materials. CONCLUSIONS This research concluded that khat chewing significantly affects bacterial biodiversity in oral biofilms in the presence of different restorative and prosthetic dental materials.

Oral Biofilm on Dental Materials Among Khat Chewers.

BACKGROUND: Nowadays khat chewing habit is increasing among population in southern part of Saudi Arabia, Jazan and till date there is no literature investigating the effect of khat on oral biofilm on dental materials. OBJECTIVE: To evaluate and compare the bacterial biofilm on different types of dental restorative materials used in replacing missing tooth structures among khat chewers and non-khat chewers. MATERIALS AND METHODS: Hundred and twenty biofilm samples were collected from different dental restorations, such as All-ceramic (AL), Metal Ceramic (MC), Metal crowns or bridges (M), Composite (C), Glass Ionomer (GI) and Amalgam (A) restorations in non-khat and khat chewers (K). DNA extraction was done and subjected to PCR. Bacterial species, such as Streptococcus, Neisseria, Bacillus, Granulicatella and Veillonella were identified and counted. PCR products were also sequenced to detect similarity. Association between bacterial type and dental materials among non-khat and khat chewers were tested with Chi-Square test (Fishers Exact test). RESULTS: The frequency and percentage of Streptococcus species were marginally higher among khat chewers (42; 70%) compared with non-khat chewers (38; 63.3%) group. But the Veillonella species were higher among non-khat chewers (9: 15%), compared to the khat chewers group (7; 11.7%). No statistically significant difference was detected among species in both groups. In non-khat and khat chewer group, the maximum hits were related to Streptococcus spp. in glass ionomer, amalgam, and composite (restorative materials), followed by metal ceramic and metal (prosthetic materials). Veillonella spp. showed maximum hits in the metal group among non-khat chewers and in all-ceramic among khat chewers. Statically significant differences were recorded among composite and amalgam samples with p values 0.047 and 0.036 in khat chewer group. CONCLUSION: Khat chewers showed statistically significant differences in oral biofilm in the composite and amalgam restorative materials, but there were no significant differences found among any materials and species between the groups.

Prosthetic Rehabilitation using a Telescopic Crown constructed with Computer-assisted Design and Computer-assisted Manufacturing: A Case Report with a 2-year Follow-up.

Aim and background: This case report describes a 74-year-old female patient whose teeth were rehabilitated using telescopic crowns (TCs) on abutments and fixed dental prostheses (FDPs) in the maxillary arch with the aid of computer-assisted design and computer-assisted manufacturing (CAD/CAM) technology. The mandibular arch was restored using casted removable dental prostheses (RDPs) and surveyed crowns. Case report: The treatment sequences were followed as recommended in the dental literature. First, existing defective restorations were eliminated, caries was removed, and excellent mouth preparation was performed. Subsequently, root canal treatments and post and core placements were conducted. The casts were mounted, and a new vertical dimension was established. Maxillary telescopic FDP and mandibular prostheses were fabricated. Finally, a regular and proper follow-up and maintenance program was implemented. Conclusion: The patient was satisfied with the esthetics and function of the telescopic FDP in the presence of the established occlusion. Clinical significance: The secondary coping of the telescopic FDP is cemented with temporary cement, which can be changed easily whenever it is loose. Furthermore, it is completely opposed to RDP in the mandibular posterior masticatory area. The prognoses will be good improvement; the patient was medically fit, motivated, and followed continual oral hygiene protocol. Keywords: Computer-assisted design, Computer-assisted manufacturing, Esthetic, Maxilla, Telescopic crown.

A multidisciplinary approach in the treatment of tempromandibular joint pain associated with qat chewing.

Pain of the tempro-mandibular joint (TMJ) has a direct bearing to missing teeth and excessive physical activity. Consumption of qat requires chewing on the leaves to extract their juice for long hours. A 65-year-old male Yemeni patient, a Qat chewer, reported to the university dental hospital at King Khalid University complaining of pain in left temporomandibular joint with missing mandibular anterior teeth. A multidisciplinary approach for the overall treatment of the patient was decided. Initial treatment was the relief of patient's pain with the help of a night guard. This was followed by a fabrication of anterior FPD. The case was under maintenance and follow-up protocol for a period of 8 months with no complaint of pain discomfort.