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Simulating the biomechanical behavior of a reconstruction using the finite element analysis method is a modern method necessary before the practical stage of a research, thus enabling the precise shaping of certain trajectories in the approach of certain directions of practical applicability, as well as obtaining final results with relevant data (results coupled with experimental models that reiterate the clinical situation that will be later analyzed).

This paper is the second part of a study regarding the biomechanical behaviour of mandibular bone in the context of different periodontal splinting systems, occlusal forces and load distributions. Electric resistive tensometry method was used to measure the strains developed in mandibular bone replica. The tests were carried out on six mandibular acrylic models, each with 8 natural teeth. The experimental groups were defined corresponding to the bone condition and splint type: normal height bone; bone resorption without splint; bone resorption and wire-composite splint; bone resorption and polyethylene fiber-reinforced composite splint. Each sample was subjected to three similar loading cycles, the force being applied successively on four incisors, two central incisors and canines, and the specific deformation values were read for four loading forces: 30 N, 50 N, 100 N and 150 N. In case of bone loss, the bone deformations are up to 110%. Periodontal splinting redistribute forces, reducing incisors bone strains associated with a slight increase in canine bone strains.

This paper is part of a larger study that aims to evaluate the biomechanical behaviour of mandibular bone and periodontal splinting systems subjected to different occlusal forces by means of electric resistive tensometry (ERT). The research was based on the following premise: the degree of bone resorption and periodontal type of splint influence the deformation of the mandibular bone. The study was conducted in two stages: first, the validation of the mandibular dental arch model, which is the subject of the present article, and second, the evaluation of mandibular bone strain in case of different types of bone loss and periodontal splints, which is the subject of a second article.

Treatment of crown root fracture is complex and requires an accurate diagnostic and treatment plan. The purpose of this article is to report a case of a maxillary central incisor with a crown-root fracture with pulp exposure treated and rehabilitated with the preservation of pulp vitality using a micro-pulpotomy and pre-mixed bioactive endodontic cements followed by zirconia restauration, a bioinert ceramic material, milled using CAD/CAM technology. The preservation of pulp vitality using premixed bioceramic materials, ensures the continuation of dentinogenesis with its benefits, higher resistance of radicular walls against fracture, smaller diameter of apical foramen as well as creating conditions over time for a post retained crown with better aesthetic results.

Medications are the primary etiologic factor in the appearance of xerostomia, dysfunction subjectively perceived by the patient as the sensation of dry mouth. The purpose of this study was to evaluate the knowledge and attitudes towards oral health in a group of adults undergoing treatment with drugs that have a secondary effect of xerostomia. The study was conducted on a sample of 64 adults with a mean age of 46-65 years with at least one chronic condition treated with at least one of the following drugs: antihypertensive, anticholinergic, antihistamine, anti-asthmatic, anxiolytic, antiparkinson, chemotherapy, oral antidiabetics, antineoplastic, antirheumatic. The results of the study show that following the administration of any of the classes of drugs administered, the side effect of xerostomia was manifested in all patients.

The use of a suitable biological material, represented by the normal cell culture cell line RM, consisting of monkey kidney cells or of suitable experimental models allow the investigation of the reactivity of the cell protein synthesis process (illustrated by the total protein content of the cell cultures aged 72 hours, after a 48-hour treatment), cell proliferation (expressed by the evolution of the total cell number during cell culture development), cell viability (characterized by the dynamics of the dead / living cells ratio), cell apoptosis and cell culture development. Alteration of these processes reflects the cytotoxic impact of some products on protein synthesis, mitosis, cell apoptosis and cell viability.

Disadvantages of diacrilic composite resins and glass ionomers cements have stimulated research to develop hybrid materials to eliminate the downsides and take advantage of their benefits. The purpose of this study was three-dimensional analysis of a flux material with a resin-modified glass ionomer (RMGI) cement in preventive sealing by two techniques of enamel substrate approach, respectively, with acidic conditioning with 37% orthophosphoric acid and free. The best results were observed in the RMGI when no substrate conditioning was performed.

Disadvantages of diacrilic composite resins and glass ionomers cements have stimulated research to develop hybrid materials to eliminate the downsides and take advantage of their benefits. The purpose of this study was comparative analysis of a resin composite and hybrid materials compomers sealing material used in preventive sealing by Energy Dispersive X-ray Spectrometry and Scanning Electron Microscopy (SEM).

This study evaluated the effects of ortophosforic acid and Er.Cr: YSGG LASER on human enamel by means of a field emission in-lens scanning electron microscope. The materials used for conditioning the teeth were SE�35% (Scotchbond� Etchant Phosphoric Acid) and MG6-MZ6 tips with Er, Cr: YSGG laser, 30% water, 60% air, 5.5 W/20 Hz according to manufacturer�s instructions. The acid time of action determines enamel demineralization in all situation. Er.Cr: YSGG laser treatment of non-carious enamel, a laser power of 5.5 W is found to be the optimal to improve the micromorphology of enamel.

This study evaluated the ultra-morphological effects of ortophosforic acid and Er.Cr: YSGGLASER on human dentin by means of a field emission in-lens scanning electron microscope. The study was conducted in vitro on human teeth extracted for orthodontic or periodontal reasons, after obtaining informed consent of patients. The samples were sectioned mesial-distal in the longitudinal direction (diamond discs) finished 400, 600, 1200 and 2400 grit SiC paper, polished with gums and abrasive paste 6, 3, 1 and 0,25 mm under continuous irrigation. The samples were divided in five groups depending on the type of conditioning as follows: GR.1= 5 s; GR.2= 10 s; GR.3= 15 s; GR.4= 20 s; GR.5= Er,Cr: YSGGlaser irradiating at 30% water and 60% air at 3W/15 Hz. The materials used for conditioning the teeth were SE�35% (Scotchbond� Etchant Phosphoric Acid -3M ESPE-Seefeld, Germany) and MG6-MZ6 tipswith Er, Cr: YSGGlaser (Biolase Waterlase-MD), according to manufacturer�s instructions. The specimens were prepared for observation under SEM with �1,000 and �4,000 magnifications. The acid type, concentration and time of action determines dentin demineralization and modifying or removing smear layer. Er.Cr: YSGG laser treatment of non-carious dentin, a laser power of 3 W is found to be the optimal to improve the micromorphology of dentin.

Selection of sealing material is a problem in terms of long-term durability. In this regard, we have been investigating the in vitro structure and in vivo retention of composite resin sealant with BIS-GMA. Bi-dimensional and three-dimensional analysis by AFM highlights a homogeneous structure with no structural retaining areas of the material. Comparative in vivo and vitro evaluation of sealing resin revealed a correlation of the analyzed aspects in terms of the retention of the material used.

The study aimed to determine the prevalence of dental midline deviation in an orthodontic group of patients.The study was performed on 384 orthodontic patients (164 boys and 220 girls), between 6-23 years old. The data collected from orthodontic records were analysed according to the gender, age stages, environments areas, type of dentition and Angle Classes of malocclusions. All analyses were carried out using the SPSS. In the studied group the prevalence of dental midline deviation was 20.70%. The prevalence of dental midline deviation was increased in girls (12.24%), in patients over 12 years old (8.35%), from urban areas (14.32%), with mixed dentition (11.45%) and with Class I (11.20%) and II division 1 (6.25%) malocclusions. We founded statistically significant high correlations between dental midline deviation and age stages (p=0.028), type of dentition (p=0.001) and Angle classes of malocclusions (p=0.006). The dental midline deviation, commonly encountered in orthodontic practice, must be accurately diagnosed from the beginning of the treatment because the symmetry of the midlines is an essential criterion in achieving the aesthetic and functional objectives of the orthodontic treatment.