ABSTRACT
This research was conducted to evaluate the knowledge and purchasing behaviour of consumers regarding lactose-free foods. Study data were collected from 1882 individuals with the help of a questionnaire form. Attitudes towards animal welfare, healthy nutrition and gastrointestinal symptoms were also evaluated. The majority (86.6%) of the participants reported that they had heard of the concept of lactose-free foods before, but more than half (67.0%) did not report buying them because of their higher costs compared to regular products and lack of sufficient information. Not causing gas/bloating (32.5%) and being healthier (28.3%) were shown to be the most significant motivational factors in purchasing lactose-free foods (P < 0.05). The factors affecting purchase of lactose-free products were education, employment status, history of having a food intolerance test and animal welfare perception together with higher scores from the gastrointestinal symptom rating scale, and attitude scale for healthy nutrition (P < 0.05). Body mass index was not found to be an effective factor determining purchase intention. The results provide a general overview of consumers, however, further studies on other demographic groups are needed.
ABSTRACT
STATEMENT OF PROBLEM: The retention of indirectly fabricated restorations can be compromised by short or over-tapered tooth preparations. PURPOSE: The aim of this study was to evaluate the retentive properties of 5 different luting cements on base and noble metal copings to short and over-tapered preparations. MATERIAL AND METHODS: Eighty extracted mandibular premolars were prepared to receive full cast copings with a flat occlusal surface, 33 degrees taper, and 3-mm axial length. Half of the standardized metal copings were cast in an AuAgPd alloy, whereas the other half were cast in an NiCr alloy. Cementation was performed with 5 different luting cements through use of 5 kg of pressure in 90% relative humidity. Specimens were stored in distilled water at 37 degrees C for 24 hours and thermocycled between 5 degrees C and 55 degrees C for 5000 cycles, with a dwell time of 30 seconds. After thermocycling, vertical tensile force was applied in a Zwick universal testing machine with a constant speed of 1 mm/min until separation was noted. A 2-factor analysis of variance was used to analyze the data, with a significance level of alpha =.05. RESULTS: Mean dislodgement forces for AuAgPd crowns and NiCr crowns were 120.88 N and 143.09 N, respectively, for zinc phosphate cement; 135.45 N and 150.38 N for Principle; 145.88 N and 220.71 N for Meron; 276.85 N and 225.61 N for Avanto; and 300.92 N and 381.02 N for Fuji Plus. CONCLUSION: Within the limitations of this study, Fuji Plus and Avanto showed significantly higher retentive strengths for AuAgPd copings in comparison to the other cements tested (P <.05). The retentive strength of Fuji Plus was significantly higher than those of the other cements tested with NiCr copings (P <.05).
Subject(s)
Dental Abutments , Dental Alloys/chemistry , Dental Bonding , Dental Cements/chemistry , Dental Prosthesis Retention , Adhesiveness , Analysis of Variance , Bicuspid , Chromium Alloys/chemistry , Glass Ionomer Cements/chemistry , Gold Alloys/chemistry , Humans , Humidity , Materials Testing , Palladium/chemistry , Pressure , Resin Cements/chemistry , Silver/chemistry , Statistics as Topic , Stress, Mechanical , Surface Properties , Temperature , Thermodynamics , Time Factors , Tooth Preparation , Water/chemistry , Zinc Phosphate Cement/chemistryABSTRACT
STATEMENT OF PROBLEM: There are few in vivo studies on the clinical performance of all-ceramic crowns. PURPOSE: The aim of this study was to evaluate the clinical performance of IPS Empress crowns. MATERIAL AND METHODS: Thirty-seven all-ceramic IPS Empress crowns were placed in 20 patients. Twenty crowns were luted with Variolink II low-viscosity resin cement in combination with Syntac Classic dentin adhesive; the remaining 17 were luted with Variolink II in combination with Syntac Single Component. All procedural steps were performed by the same prosthodontist. Using the California Dental Association's (CDA) quality evaluation system, 2 calibrated evaluators examined the crowns for margin integrity, anatomic form, surface, and color for a period of 12 to 41 months, with a mean of 24.56 months after insertion. Kaplan-Meier statistical analysis was used to calculate the survival rate of the crowns. Values obtained for plaque and gingival conditions were compared to control teeth with use of the Wilcoxon signed ranks test (P<.05). RESULTS: Based on the CDA criteria, 94.6% of the crowns were rated satisfactory. Fracture was registered in only 1 crown. One endodontically treated tooth failed due to the dislodgement of the prefabricated dowel. No significant difference was observed in the gingival health status of crowns that had margins placed above or at the level of the gingival margin. However, in crowns that had subgingival margin finish lines, the percentage of bleeding on probing was significantly higher than that of the contralateral control teeth. CONCLUSION: In this in vivo study, IPS Empress crowns luted with both dentin bonding agents functioned satisfactorily with a relatively low fracture rate over a mean evaluation period of 24.56 months.
