ABSTRACT
The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture loads and microleakage in all-ceramic crowns cemented with two types of polymeric bioactive cements and resin cements. In addition, the degree of color change for each cement with coffee was assessed. Thirty maxillary premolar teeth for fracture loads and thirty mandibular premolar teeth for microleakage were prepared; standardized teeth preparations were performed by a single experienced operator. All prepared specimens were randomly distributed to three groups (n = 20) based on the type of cement, Group 1: resin cement (Multilink N); Group 2: polymeric bioactive cement (ACTIVA); Group 3: polymeric bioactive cement (Ceramir). The cementation procedures for all cements (Multilink, ACTIVA, and Ceramir) were performed according to the manufacturers' instructions. All specimens were aged using thermocycling for 30,000 cycles (5-55 °C, dwell time 30 s). These specimens were tested using the universal testing machine for fracture strength and with a micro-CT for microleakage. For the color stability evaluation, the cement specimens were immersed in coffee and evaluated with a spectrometer. Results: The highest and lowest means for fracture loads were observed in resin cements (49.5 ± 8.85) and Ceramir (39.8 ± 9.16), respectively. Ceramir (2.563 ± 0.71) showed the highest microleakage compared to resin (0.70 ± 0.75) and ACTIVA (0.61 ± 0.56). ACTIVA cements showed comparable fracture loads, microleakage, and stain resistance compared to resin cements.
Subject(s)
Filtering Surgery , Glaucoma Drainage Implants , Glaucoma/surgery , Adolescent , Child , Equipment Design , Female , Glaucoma/congenital , Humans , Intraocular Pressure , Male , Retrospective Studies , Treatment OutcomeABSTRACT
INTRODUCTION: Macular edema is responsible for a significant degree of visual loss in diabetic patients. The prognosis factors in diabetic macular edema are varied and better documented by optical coherence tomography (OCT). We describe the patterns of diabetic macular edema demonstrated by OCT and correlate them with visual acuity. PATIENTS AND METHOD: A prospective study of 297 eyes with diabetic macular edema was conducted. An OTI/OCT exam was done for all eyes. The Fisher test was used to search for a correlation between visual acuity and each feature of diabetic macular edema (macular thickness, cystoid macular edema, central cyst, tractional component, and serous retinal detachment). RESULTS: Visual acuity varied from 1.3 log MAR to 0 log MAR. The mean visual acuity was 0.51 log MAR. The presence of central cyst on OCT scan was significantly associated with worse vision (p<0.0001). Increased retinal thickness in all patterns was significantly correlated with worse visual acuity (p<0.0001). The OCT patterns containing a tractional component and serous retinal detachment were also associated with visual loss (p<10(-6)). CONCLUSION: OCT is a very useful objective tool to describe, classify, and manage diabetic macular edema. It provides a better analysis of different prognosis factors and therefore can assist in determining a more suitable treatment for diabetic macular edema.
