Author(s):
1. Vladimir Biočanin, Stomatoloski fakultet, Pančevo, Serbia
2. Nemanja Vuković, Department of Oral surgery, Faculty of Stomatology, Pančevo, Serbia
3. Marija Ćirić, Private practice, Belgrade, Serbia, Serbia
4. Veljko Ilic, 'Stomatoloski fakultet Univerzitet u Beogradu, Serbia
5. Đorđe Antonijević, Department of Anatomy, School of Dental medicine, Belgrade, Serbia, Serbia
6. Vukoman Jokanović , University of Belgrade, Vinča Institute of Nuclear Sciences, Serbia, Serbia

Abstract:
Introduction Calcium silicate (CS) dental cements were successfully used for the retrograde root canal surgical obturation, pulp capping, apexification and apexogenesis of immature teeth and root canal perforations repair. The success arose from advantages of CS in copmatrison to previously used calcium hydroxyde (CH) having in mind two slower release of calcium ions with consequently longer preserving of high pH value on the pulp inflammatory site and superior physical properties of CS with subsequent lack of the cement resorption as can be seen in CH. In line with latter advantages go efforts to introduce novel cement with even superior physical characteristics than in CS. Accordingly, calcium aluminate (CA) dental cements were introduced recently. Microporosity od dental cements is of special importance in its physico-chemical features. Aim The aim of this study was to compare microporosity of comercialy used CS dental cement with experimental CA dental cements. Methods Dental cements were mixed with distilated water (3:1 ratio) and specially designed Teflon molds (8mm base diametre and 2 mm in height) were filled with one of the following materials: ProRoot MTA (Dentsply, Tulsa, OK, USA), Ca-aluminate, Ca-aluminate with strontium carbonate (SrCO3), Ca-aluminate with strontium fluoride (SrF2).The microporosity of the cements was determined by scanning the specimens with a micro–computed tomographic (μ CT) scanner (SkyScan 1172; Bruker microCT, Kontich, Belgium) operated at 73 kV and 135 mA with an exposure time of 1200 milliseconds, a copper aluminum filter, a rotation of 180 in 0.4 steps, frame averaging of 3.5- mm isotropic resolution, and 2048x2048 pixels per slice. Results Microporosity among tested dental cements was not statisticaly significant ANOVA (p=0.774). Experimental pure CA cement and CA cements wit the addition of SrF2 and SrCO3, showed low values of microporosity, similar to MTA . Discussion and conclusions Microporosity assessed by micro CT is the measure of the closed pososity. This parameter reflects the ability of the material to resist mechanical fracture having the lower values of close porosity being less prone to microcracks appearance. On the other hand, higher micopores are related with possibility of the material to fracture and consequently allow the formation of microchanels through which the infection and bacteria enclosed within dentinal tubules may reach periapical tissue. Likewise, microporosity directly affects solubility of dental cements. Bastruk et al. (2014) used μCT for the microporosity testing of different formulations of MTA, got microporosity around 2%, similar to the result from our study for microporosity of Pro Root MTA (2.32%). In our study, all tested dental cements showed low values of microporosity.

Key words:
calcium-aluminate,calcium silicate,dental cements,microporosity,micro-CT

Thematic field:
SYMPOSIUM B - Biomaterials and nanomedicine

Date of abstract submission:
01.08.2022.

Conference:
Contemporary Materials 2022 - Savremeni materijali

Abstract