A polymer-infiltrated ceramic network (PICN) material has recently been introduced for dental use and evidence is developing regarding the fit accuracy of such crowns with different preparation designs. The aim of this in vitro study was to evaluate the precision of fit of machined monolithic PICN single crowns in comparison to lithium disilicate crowns in terms of marginal gap, internal gap, and absolute marginal discrepancies. A secondary aim was to assess the effect of finish line configuration on the fit accuracy of crowns made from the two materials. Two master metal dies were used to create forty stone dies, with twenty each for the two finish lines, shoulder and chamfer. The stone dies were scanned to produce virtual models, on which ceramic crowns were designed and milled, with ten each for the four material–finish line combinations (n = 10). Marginal gaps and absolute marginal discrepancies were evaluated at six pre-determined margin locations, and the internal gap was measured at 60 designated points using a stereomicroscope-based digital image analysis system. The influence of the material and finish line on the marginal and internal adaptation of crowns was assessed by analyzing the data using two-way analysis of variance (ANOVA), non-parametric, and Bonferroni multiple comparison post-hoc tests (α = 0.05). ANOVA revealed that the differences in the marginal gaps and the absolute marginal discrepancies between the two materials were significant (p < 0.05), but that those the finish line effect and the interaction were not significant (p > 0.05). Using the Mann–Whitney U test, the differences in IG for ‘material’ and ‘finish line’ were not found to be significant (p > 0.05). In conclusion, the finish line configuration did not seem to affect the marginal and internal adaptation of PICN and lithium disilicate crowns. The marginal gap of PICN crowns was below the clinically acceptable threshold of 120 µm.

Introduction Celiac disease (CD) is one of the most common chronic gastrointestinal disorders in the world. Currently, the literature about the dental profiles of patients with celiac disease is sparse and no studies have reported on the oral conditions and caries status of CD patients in Kuwait. Objective This study investigated the association between CD and caries experience. Methods Two groups were examined; study and control. The study group consisted of controlled celiac disease patients. The control group consisted of subjects who were matched for age and gender to the study group participants. Both groups received clinical and radiographic examinations of their oral cavity. Parameters recorded for the study purposes were—dental caries index (decayed, missing, and filled teeth), salivary flow rates (stimulated and unstimulated), salivary buffering capacity and Lactobacilli and mutans Streptococci bacterial counts. Results Patients with CD had statistically significant fewer missing teeth than the controls. There were no other significant differences. Measured stimulated and unstimulated salivary flow rates and salivary buffering capacity showed no statistical differences. Bacterial counts revealed no significant differences. Conclusion Adult patients with controlled CD showed fewer missing teeth than their counterparts. Other caries and salivary parameters showed no statistical differences between the two groups.

Objective To investigate the knowledge, attitude, and possible barriers to fluoride application among oral health-care providers in Kuwait. Methods A validated self-administered questionnaire was distributed to a random sample of 291 dentists. The questionnaire included four categories: dentists' characteristics, knowledge of and attitude towards fluoride application, factors influencing decision-making on prescription of fluoride, and the clinician's perception of own knowledge. Means, group differences, and logistic regression were calculated. Results 262 completed the questionnaire (response rate of 90%). Half of the participants (49%) reported that water fluoridation is the best method for caries prevention in children. Majority of the participants (80%) acknowledged that topical fluoride prevents dental caries, but only 40% frequently use it in their practices. Fear of overdose was a concern in 57% of the participants. About 31% believed that caries is a multifactorial disease and cannot be prevented. In addition, 32% of the dentists who thought caries is multifactorial and cannot be prevented stated that restorations take precedence over preventive therapy. Conclusion Despite the participants being in favor of topical fluoride application and believing in its effectiveness, certain barriers were apparent such as knowledge deficiencies, products labelling flaw, and lack of participation in effective continuing educational activities.

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Purpose To evaluate the marginal and internal fit of monolithic computer‐aided design/computer‐aided manufacturing (CAD/CAM) ZLS (Vita Suprinity) glass ceramic porcelain laminate veneers (PLVs), in terms of marginal and internal gap widths, in comparison to monolithic lithium disilicate (LDS) [IPS e.max CAD] CAD/CAM veneers, and, also, to analyze the effect of incisal preparation designs (butt joint and chamfer), on the marginal and internal fit accuracy. Materials and Methods Forty dental stone dies poured from impressions made of two master metal dies with different incisal preparation designs were scanned to produce digital models. Forty ceramic veneers were designed and milled using the virtual models‐10 ZLS butt joint, 10 ZLS chamfer, 10 LDS butt joint, and 10 LDS chamfer. The monolithic ceramic veneers produced were then subjected to marginal and internal gap width evaluation using X‐ray nano‐computed tomography and computerized digital analysis (n = 10). Descriptive analyses of data were performed and the influence of “material” and “preparation design” on the marginal and internal fit of veneers was assessed using 2‐way ANOVA (α = 0.05). Bonferroni post‐hoc multiple comparison tests were used to further analyze the interactions between the material and preparation design after adjusting the α value by Holm‐Bonferroni method (α = 0.01). Results Mean marginal and internal gaps for ZLS PLVs were 65 ±11 μm and 112 ±14 μm for butt joint, and 100 ±24 μm and 100 ±21 μm for chamfer, respectively. Corresponding values for LDS PLVs were 78 ±25 μm and 114 ±17 μm for butt joint, and 104 ±18 μm and 106 ±7 μm for chamfer. Marginal gap and internal gap differences between ZLS and LDS PLVs were not significant (marginal gap: F = 1.786, p = 0.190; internal gap: F = 0.807, p = 0.375). However, the preparation designs (butt joint and chamfer) differed significantly in terms of marginal gaps (F = 23.797, p = 0.000), but not internal gaps (F = 3.703; p = 0.059). Conclusions Butt joint margins produced better marginal accuracy in terms of marginal gap, compared to chamfers, for ZLS CAD/CAM laminate veneers.