The Influence of Chlorhexidine Gluconate Dentine Pre-Treatment on Adhesive Interface and Marginal Sealing.

Background and Objectives: The aim of this in vitro study was to evaluate the combined effect of a 2% chlorhexidine aqueous solution and a universal adhesive system applied in self-etch and etch-and-rinse strategies on the composite resin-dentin interface. Materials and Methods: Class V cavities were prepared on the facial and lingual surfaces of forty caries-free molars extracted for orthodontic reasons. The samples were randomly divided into two groups corresponding to the used etching protocol: I-etch-and-rinse; II-self-etch. In each tooth, one cavity was assigned for the control subgroups -IA (n = 20) and IIA (n = 20)-adhesive only, and the opposite cavity was pretreated with a 2% chlorhexidine solution-Gluco CHeX Cerkamed-subgroups IB (n = 20) and IIB (n = 20). Both sets of groups were restored using a universal adhesive system (Single Bond Universal Adhesive, 3M-ESPE) and a bulk-fill composite resin (Filtek One Bulk Fill Restorative, 3M-ESPE). The roots and the pulp tissue were then removed, and a needle connected to a perfusor with 100 mL saline solution was used for pulp pressure simulation with a hydrostatic pressure of 20 cm H2O. Cariogenic attack was simulated using a demineralizing solution for 3 days at a constant temperature of 25 °C. The teeth were then sectioned in a facial-lingual direction and the microleakages at the occlusal and cervical margins were registered and scored using an optical Carl-Zeiss AXIO Imager A1m microscope (Carl-Zeiss). The composite resin-dentin interface was analyzed using a SEM Vega Tescan LMH II. Statistical analysis was performed using the Kruskal-Wallis test with a significance level of p < 0.05. Results: Microleakage evaluation showed no significant differences among the study groups (p > 0.05). In subgroup IA, significant differences were recorded between occlusal and cervical margins (p < 0.05). Conclusions: Application of chlorhexidine on tooth substrate before using a universal bonding system in total etch or self-etch mode has no influence on the adhesive interface in the condition of cariogenic attack. The thickness of the adhesive resin layer seems to be less uniform when using chlorhexidine, but the morphological differences at the adhesive interface have no influence on the sealing capacity of the universal bonding system, regardless of the etching strategy.

The Impact of Simulated Gastric Acid and Toothbrushing on Surface Characteristics of Resin-Modified Glass-Ionomer Cements.

Background and Objectives: The aim of this in vitro study was to evaluate the effect of simulated gastric acid associated with toothbrushing on the surface condition of three resin-modified glass-ionomer cements (RMGIC). Materials and Methods: One hundred and sixty samples of each material were obtained and included in three study groups according to the tested material: Group I (Ionolux, VOCO GmbH, Cuxhaven, Germany); Group II (Vitremer, 3 M-ESPE, St. Paul, MN, USA); and Group III (Fuji II LC, GC Corporation, Tokyo, Japan). The samples were submersed in hydrochloric acid 0.01 M (pH 3.8) for 3 h and exposed to a toothbrushing procedure at a frequency of 10,000 cycles with medium and hard bristles immediately or 30 min after the acid attack. Profilometric measurements were performed by using a non-contact profilometer (Dektak XT, Bruker, Billerica, MA, USA) in order to assess the surface roughness. ANOVA and Bonferroni post hoc tests were used for the statistical analysis at a significance level of p < 0.05. Results: Exposure of RMGICs to the erosive effect of hydrochloric acid in association with toothbrushing 30 min after the chemical attack increased the surface roughness of all three RMGICs. Exposure of the three tested materials exclusively to the action of hydrochloric acid did not affect the surface roughness. Conclusions: One year of hydrochloric acid challenge associated with one year of toothbrushing with medium-hardness bristles performed 30 min after the acid attack increase the surface roughness of two of the three types of RMGIC tested (Ionolux and Fuji II LC).

Conventional and Resin-Modified Glass Ionomer Cement Surface Characteristics after Acidic Challenges.

The aim of the present study was to assess by atomic force microscopy (AFM) the surface roughness of a traditional glass ionomer cement- GIC (Fuji IX GP, GC Corporation, Tokyo, Japan) and a resin modified glass ionomer cement- RMGIC (Vitremer, 3M ESPE, St. Paul, MN, USA) after different immersion regimes on some acidic drinks. Sixteen cylindrical samples having the height of 5 mm and the thickness of 2 mm were obtained from each material and they were divided into two groups: Group I (Fuji IX samples) and Group II (Vitremer samples). Specimens of each group were then randomly divided into 4 subgroups: subgroup A (control)-15 samples were kept in artificial saliva and in the other three subgroups, each having 15 samples the samples were immersed in Coca-Cola (subgroup B), Cappy lemonade and mint (subgroup C) and Fuzetea (subgroup D) for 7 days (subgroups A1-D1), 14 days (subgroups A2-D2), and 21 days (subgroups A3-D3). AFM qualitative and quantitative surface evaluation (mean value of surface roughness parameter, Sa) of each sample was performed. The highest surface roughness was determined when both materials were submerged 14 days in acidic drinks. Traditional GIC was more affected by acidic environment when comparing to RMGIC.

[Evaluation of caries activity using the micro-crystallization saliva index (IMK)]. / Evaluarea activitatii bolii carioase cu ajutorul indicelui de microcristalizare salivara.

The dental decay activity of a patient can be evaluated with the help of certain indirect signs that reveal the dental decay risk elements. The quantity, buffer capacity, inorganic components of the saliva are important in the pathogenesis of dental decay. The micro-crystallization saliva test (IMK) may represent an important criterion on whose basis one obtains an evaluation of the re-mineralization capacity of saliva. The purpose of this study consisted in the calculation of the IMK index on a lot of patients and its correlation to the type of dental decay activity. The study was conducted on a lot of 30 patients with ages between 18 and 45, nursed and examined every 6 months during 18 months. The attention was focused on the following parameters: the index of micro-crystallization (IMK) and the dental decay activity, calculated as rate of appearance of new dental lesions within 18 months. As a result of investigations, the authors observed the following correlations to dental decay activity: the patients with IMK = 1/0.6 did not have any new dental lesion, in the patients with IMK = 0.6/0.4 new dental lesions appeared within 12-18 months and in the patients with IMK = 0.4/0 new dental lesions appeared in less than 6 months after examination. The IMK index--indicator of the re-mineralization capacity of saliva, may be evaluated using a relatively simple methodology, accessible and at a moderate price. Research pointed out that this index may be an useful instrument when evaluating the dental decay susceptibility of patients, contributing to the identification of the dental decay risk and consecutively to the choice of individualized prophylactic and therapeutic procedures.

[The cariogram principle applied to the patients with high caries risk]. / Principiul cariogramei aplicat la pacienti cu risc cariogen mare.

The "Cariogram" is a new concept, conceived initially as an educational model, aiming at illustrating the multifactorial background of dental caries in a simple way. This educational interactive program has been developed for better understanding of the multifactorial aspects of dental caries and to act as a guide in the attempts to estimate the caries risk. Caries risk is the probability that an individual will develop carious lesions, reaching a given stage of the disease in progression during a specified period of time, conditional that the exposure status for risk factors remains stable during the period in question. For patients with high caries risk, efforts should be made to increase the "chance" sector and reduce each sector responsible for caries risk and particularly the unfavorable one.

[Use of biopolymer membrane diplen-F in treatment of initial enamel carious lesion on smooth surfaces]. / Utilizarea membranelor biopolimerice diplen-F în tratamentul leziunilor incipiente de smalt de pe suprafetele netede.

The aim of the study was to evaluate the possibility of using a fluoride product included in a biodegradable membrane in remineralization of initial enamel carious lesions. The membrane has anti-bacterial, anti-inflammatory and remineralization properties, with a long-term effect. The efficiency of this treatment was assessed by measuring the surface of the demineralization area and its depth. The results proved that the use of this membrane in association with remineralization therapy of the initial enamel carious lesions increase the chances of success and represents a simple solution easily accepted by the patients.