Influence of radiopacifying agents on the solubility, pH and antimicrobial activity of portland cement

Abstract

The aim of this study was to evaluate the interference of the radiopacifiers bismuth oxide (BO), bismuth carbonate (BC), bismuth subnitrate (BS), and zirconiun oxide (ZO) on the solubility, alkalinity and antimicrobial properties of white Portland cement (WPC). The substances were incorporated to PC, at a ratio of 1:4 (v/v) and subjected to a solubility test. To evaluate the pH, the cements were inserted into retrograde cavities prepared in simulated acrylic teeth and immediately immersed in deionized water. The pH of the solution was measured at 3, 24, 72 and 168 h. The antimicrobial activity was evaluated by a radial diffusion method against the microorganisms S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), E. faecalis (ATCC 29212) and C. albicans (ATCC 10231). The zone of microbial growth inhibition was measured after 24 h. The addition of BS and BC increased the solubility of the cement. The pH values demonstrated that all materials produced alkaline levels. At 3 h, BS showed lower pH than WPC (p<0.05). At 168 h, all materials showed similar pHs (p>0.05). The materials did not present antimicrobial activity for S. aureus, P. aeruginosas and E. faecalis (p>0.05). With regards to C. albicans, all materials formed an inhibition zone, mainly the mixture of WPC with ZO (p<0.05). The type of radiopacifier incorporated into WPC interfered with its physical and antimicrobial properties. ZO was found to be a viable radiopacifier that can be used with WPC.

Success Rate of Medcem Portland Cement as a Pulp Capping Agent in Pulpotomies of Primary Teeth

“…The reason for this interest is the same physical and mechanical qualities and at the same time lower cost of PC compared to MTA [7,8,[12][13][14][15].…”

“…The main disadvantage of PC is that it is not radiopaque [10, 13,15,16]. The absence of radiopacity makes it difficult to distinguish PC from dentin and other anatomic structures and compromises the evaluation of biocompatibility between PC and the human pulp tissue [17].…”

“…aim to evaluate their effect on its biocompatibility [17,18] and their impact on its physical and chemical qualities [10, 15,16]. Some of the radiopaque additions can affect its strength and increase the setting time of PC [19] without changing its biological effect [18] but these additions lead to colour changing of the treated tooth [20].…”

“…Because of this, there are not enough results to be found for its use in teeth of the primary and secondary dentition in the specialised literature [22]. There are some experimental studies which compare both materials (PC and MTA) and which describe them to be very similar and to have the same effect as a pulp capping agent used in primary teeth [15]. Antibacterial activity and a similar effect on pulpal cells have been shown when MTA or PC are used for direct pulp capping in rat teeth [23].…”

Mineral Trioxide Aggregate: A review of clinical usage and investigations of the effects of modifying particle size

“…Therefore, their inclusion results in detriment to the CS, prolongs setting time and increases solubility. 79,80,144,145 HDCs that opt to use alternative radiopacifiers to BO may either have a substantially higher proportion of radiopacifier in their efforts to be as radiopaque as MTA-P, or may not be as radiopaque as MTA-P.…”