ABSTRACT
PURPOSE: Preformed metal crown (PMC) were considered as the best method of restoring primary molars. In recent years, dentistry has seen the emergence of esthetic full-coverage restorative alternatives that gave better results but their ability to manipulate the size, shape, and fit is very limited. The milled zirconia crown is a new alternative for the restoration of deciduous teeth, but the mechanical properties of these restorations need to be tested. AIM: To assess and compare the force required to fracture on two posterior pedodontics crowns: a prefabricated Zirconia crowns (PZC) (NuSmile Zr Zirconia®) and a new custom-made zirconia crown (also called Zirkid©) on a freshly extracted deciduous molars. METHODS: Thirty freshly extracted deciduous molars were selected and were randomized into two groups: (1) molars prepared to receive the PZC and (2) molars prepared to receive the milled zirconia crowns. All pediatric crowns were cemented with glass ionomer and the samples were placed in the thermocycling machine for thermal aging of 1000 cycles. Mechanical compression forces were applied using the Universal Testing Machine until fracture of the crowns. The force required to fracture were evaluated. Since variable was normally distributed with Kolmogorov-Smirnov test, Student t test was used for statistical comparison. RESULTS: This study showed that the mean fracture force was significantly elevated with zirconia crowns made with Zirkid© (2888.6 ± 1060.2 N) compared to NuSmile Zr crowns (646.5 ± 223.9 N) (p value < 0.001). CONCLUSION: Considering the limitations of the present in vitro study, further in vitro and in vivo studies are required to support the use of Zirkid© in primary molar teeth restorations and to assess others mechanical properties.
Subject(s)
Flexural Strength , Zirconium , Child , Crowns , Dental Restoration Failure , Humans , Materials Testing , MolarABSTRACT
Objectives. To compare the clinical performances of a self-adhering resin composite and a conventional flowable composite with a self-etch bonding system on permanent molars. The influence of using rubber dam versus cotton roll isolation was also investigated. Materials and Methods. Patients aged between 6 and 12 years and presenting at least two permanent molars in need of small class I restorations were selected. Thirty-four pairs of restorations were randomly placed by the same operator. Fifteen patients were treated under rubber dam and nineteen using cotton rolls isolation and saliva ejector. They were evaluated according to the modified USPHS criteria at baseline, 6 months, and 1 and 2 years by two independent evaluators. Results. All patients attended the two-year recall. For all measured variables, there was no significant difference between rubber dam and cotton after 2 years of restoration with Premise Flowable or Vertise Flow (p value > 0.05). The percentage of restorations scored alpha decreased significantly over time with Premise Flowable and Vertise Flow for marginal adaptation and surface texture as well as marginal discoloration while it did not vary significantly for color matching. After 2 years, Vertise Flow showed a similar behaviour to the Premise Flowable used with a self-adhesive resin system.
ABSTRACT
The relationship between adherence to antihypertension medications, treatment satisfaction and illness perception has not been studied so far. The primary objective of this study was to examine the association between adherence to medication, treatment satisfaction and illness perception in Lebanese hypertensive patients. The relation between medication adherence and blood pressure (BP) control was also assessed. In this cross-sectional study, patients were recruited from the physician's practice offices and community pharmacies in Beirut. Patients who had been treated for hypertension for at least 3 months were invited to participate in the study; they completed three questionnaires: the 8-item Morisky Medication Adherence Scale (MMAS-8), the Treatment Satisfaction Questionnaire for Medication (TSQM-4) and the Brief Illness Perception Questionnaire (BIPQ). BP was also measured and recorded. A total of 117 subjects were included, of whom 29.1% had poor adherence to their antihypertension treatment (MMAS-8 scores<6). The odds of having well-controlled hypertension was 3.5 times higher in patients with high adherence compared with patients with poor adherence (P=0.010). Treatment satisfaction was significantly greater in patients with good adherence (P<0.001). Neither socio-demographic, disease- nor drug-related characteristics of the participants were significantly associated with medication adherence. As for illness perception, even though the mean BIPQ score of adherent participants was lower than the mean score of non-adherent participants, this difference did not reach statistical significance. In conclusion, treatment satisfaction was found to be a predictor of adherence. Studies are needed to determine whether interventions to increase satisfaction can improve adherence and BP control.
