Mechanical resistance of restored teeth with extensive crown damage

Introduction. Extensively damaged teeth can be restored by different core build-up materials. The aim of this study was to examine the mechanical properties of the restored maxillary premolars with composite resin, dental amalgam and glass ionomer cement (GIC) using compressive strength test. Materials and methods. Forty extracted intact human maxillary premolars were used in this study. Artificial defect in dentin was prepared using diamond bur up to the half of the anatomic crown of the tooth. After core build-up procedure, each tooth specimen was mounted in auto polymerizing acrylic resin blocks 2 mm below cement enamel junction and they were kept in distilled water at 37°C one day before testing. Then, they were placed in specially adapted devices at the angle of 183° to the longitudinal axis and subjected to a controlled load of 1 mm per minute. Results. Results showed that the best mechanical properties had samples restored with resin composite (492.5 N), then with amalgam (341.2 N) and glass ionomer cement (171.8 N). Comparing the fracture force using ANOVA, there was statistic significance between these groups (p<0.01). There were significant differences among control group and restored teeth with composite resin, amalgam and GIC. There was no significant difference in values of fracture forces between groups with composite resin and amalgam. The fracture force corresponding to the teeth restored with the GICs was significantly lower compared to the control group and the group with composite resin and amalgam. Conclusion. Satisfactory mechanical properties of restored premolars were obtained using composite resin and dental amalgam as a core build-up material

Influence of different types of surgical suture material on the intensity of tissue reaction in oral cavity

Throughout the history the most diverse suture material have been used for closing and suturing surgical wounds. The four basic features of suture material are described: knot safety, stretch capacity, tissue reactivity and wound safety. Tissue reaction, even the minimum one, which develops during the first to seven days after applying the suture in the tissue. The aim of this study was to investigate influence of a monofilament suture material (nylon) on the intensity of local tissue reaction in experimental conditions, and to compare it with the multifilament suture used in the routine practice of oral surgery (silk). This investigation is a prospective experimental study carried out on Wistar rats. The experiment included 30 animals, in which Black Silk (thickness 4-1) and Nylon (thickness 4-0) were applied in the upper and lower jaw, respectively. To monitor tissue reaction on different suture materials the following parameters were used: coagulum formation, presence of polymorphonuclear leukocytes, presence of macrophages and granuloma, formation of epithelial bridge and connective tissue, collagen synthesis, granulomatous tissue formation and presence of fibrous tissue. After comparing parameters for the intensity of tissue reaction to the investigate suture materials by suturing the oral mucosa, certain advantage could be given to the monofilament suture materials

Cytotoxicity and fibroblast properties during in vitro test of biphasic calcium phosphate/poly-dl-lactide-co-glycolide biocomposites and different phosphate materials

Reconstruction of bone defects is one of the major therapeutic goals in various clinical fields. Bone replacement materials must satisfy a number of criteria. Biological criteria are biocompatibility, controlled biodegradability, and osteoconductive or even osteogenic potential. The material should have a three-dimensional structure with an interconnected pore system so as to permit cell growth and transport of substances. The surface must permit cell adhesion and proliferation. Composite biomaterials have enormous potential for natural bone tissue reparation, filling and augmentation. Calcium hydroxyapatite/polymer composite biomaterials belong to this group of composites and, because of their osteoconductive and biocompatible properties, can be successfully implemented within bone tissue reparations. In this study, possible differences between BCP/DLPLG, pure BCP, and Bio-Oss® materials were examined in vitro. During overnight incubations, fibroblast and fibroblast-like cells (L929, MRC5) were able to adhere, spread, and remain viable on BCP, BCP/PLGA, and Bio-Oss® discs, as was evidenced by using light- and LVSEM-microscopy. Inhibiting influence over the cell growth is more pronounced in the cases of BCP usage on both cell lines—41.29% for L929 and 43.08% for MRC-5 cells. MRC-5 cells are, within the given experimental conditions, less sensitive on inhibiting effects for the materials BCP/PLGA and Bio-Oss® (10.13% and 10.76%, respectively) than for the L929 cell lines (23.02% and 15.44%, respectively)

Comparison of efficacy of local hemostatic modalities in anticoagulated patients undergoing tooth extractions

Background/Aim. Patients receiving long-term oral anticoagulant therapy pose a clinical challenge during invasive dental procedures. The goal of this study was to compare different local hemostatic modalities after tooth extraction in patients receiving chronic Vitamin-K antagonist therapy. Methods. Totally 90 patients with International Normalized Ratio (INR) ≤ 3.0 requiring simple extraction of one or two teeth were randomized into three groups, 30 patients in each group. The patients with the mean INR value of 2.35 ± 0.37, in whom extraction wound was sutured comprised the group A. In the group B with the mean INR of 2.43 ± 0.4, local hemostasis was achieved by placing absorbable gelatin sponges into the wound without suturing. The group C consisted of the patients with the mean INR of 2.36 ± 0.34 in whom neither gelatin sponge nor suturing were used for providing local hemostasis. Bleeding was registered as an event if other than initial hemostatic measure was needed or additional oral surgeon intervention required. Results. The obtainded results show that 1 (3.3%) patient in the group A, 2 (6.7%) patients in the groups B and C manifested post-extraction bleeding. All cases of hemorrhage were easily solved with local hemostatic measures and all, except one case, were registered in the first two hours after the procedure until the dismissal. A difference between the groups was not statistically significant (χ2 = .42, p > 0.05). Conclusion. In therapeutically anticoagulated patients tooth extractions can be safely performed without altering the dose of anticoagulant medication if efficient local hemostasis is provided. In most cases, in patients with INR ≤ 3.0 after extraction of one or two teeth postoperative bleeding can be controlled with local pressure, without any additional local hemostatic measures