title: Thermal cycling for restorative materials: does a standardized protocol exist in laboratory testing? A literature review.
abstract: In vitro tests continue to be an indispensable method for the initial screening of dental materials. Thermal cycling is one of the most widely used procedures to simulate the physiological aging experienced by biomaterials in clinical practice. Consequently it is routinely employed in experimental studies to evaluate materials' performance. A literature review aimed to elucidate test parameters for in vitro aging of adhesive restorations was performed. This study aims to assess whether or not a standardized protocol of thermal cycling has been acknowledged from a review of the literature. An exhaustive literature search, examining the effect of thermal cycling on restorative dental materials, was performed with electronic database and by hand. The search was restricted to studies published from 1998 to August 2013. No language restrictions were applied. The search identified 193 relevant experimental studies. Only twenty-three studies had faithfully applied ISO standard. The majority of studies used their own procedures, showing only a certain consistency within the temperature parameter (5-55°C) and a great variability in the number of cycles and dwell time chosen. A wide variation in thermal cycling parameters applied in experimental studies has been identified. The parameters selected amongst these studies seem to be done on the basis of convenience for the authors in most cases. A comparison of results between studies would appear to be impossible. The available data suggest that further investigations will be required to ultimately develop a standardized thermal cycling protocol.
authors.affiliation: Unit of Restorative Dentistry, Oral Pathology, Department of Life, Health and Environmental Sciences, School of Dentistry, University of L'Aquila, L'Aquila, Italy.
authors.forename: Anna Lucia
authors.initials: AL
authors.lastname: Morresi
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Amario
authors.forename: Mario
authors.initials: M
authors.lastname: Capogreco
authors.forename: Roberto
authors.initials: R
authors.lastname: Gatto
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Marzo
authors.forename: Camillo
authors.initials: C
authors.lastname: D'Arcangelo
authors.forename: Annalisa
authors.initials: A
authors.lastname: Monaco
mesh_terms: D017266:Dental Prosthesis; D006801:Humans; D007753:Laboratories / Q000592:standards*; D008422:Materials Testing / Q000592:standards*; D012015:Reference Standards; D013696:Temperature; D013997:Time Factors
keywords: Aging; Dental restorations; In vitro tests; Standardization; Thermal cycling.