Quintessence International, 02/2015

Objective: To evaluate the fracture resistance and failure types of modified H-designed intradental short retention preparation for computer-aided design/computer-assisted manufacture (CAD/CAM) restorations, in cases where no ferrule is possible. Method and Materials: A combined finite element analysis and in vitro testing was employed. Forty extracted single-rooted premolars were selected and prepared for the following four groups (n = 10 per group): Group A, H-post preparation restored with glass-ceramic crowns; group B, H-post preparation restored with lithium disilicate crowns; group C, endocrowns (negative control group); and group D, 2-mm ferrule preparation and restoration with fiber posts (positive control). After cementation, specimens were loaded to fracture (1 mm/min) in a universal testing machine. The data were analyzed using Kolmogorov-Smirnov, Shapiro-Wilk test, one-way ANOVA, followed by post-hoc Scheffé test and chisquare test. Results: The H-post group restored with lithium disilicate crowns (group B) presented higher fracture resistance compared to the H-post group with glass-ceramic crowns (group A) and the endocrowns (group C). Among the failure analysis, only specimens of group C were all repairable after fracture load test, while the specimens of remaining groups A, B, and D accounted for 90%, 70%, and 50% repairable fracture modes, respectively. Conclusion: The modification of the short intracoronal restoration anchorage profile may be a valid concept to improve the retention and fracture resistance, given that the materials are adjusted for this purpose in terms of mechanical resistance and internal adaptation. Numerical evaluations and future in vitro studies may help to select the best designs and materials. Keywords: bonding, CAD/CAM, ceramic, failure types, finite element analysis, fracture resistance

Oligodontia has a substantial oral functional and psychosocial impact on the quality of life of children. The treatment of oligodontia in adolescence is an interdisciplinary approach which can include extraction of the primary teeth with orthodontic space closure, or prosthodontic rehabilitation. This case report describes a conservative approach for the rehabilitation of a 12-year-old patient with 19 ageneses (excluding third molars) of permanent teeth, infraocclusion of the persisting primary teeth, deep overbite, and reduced mesiodistal dimension of the maxillary incisors with a central diastema. The treatment plan to restore esthetics and function included an initial noninvasive prosthetic rehabilitation for deep bite correction with additive leucite-reinforced glass-ceramic onlays/veneers until definitive orthodontic and implant therapy are reevaluated and determined in adulthood. Esthetics, functional occlusion, and crown-to-root ratio remained stable over a follow-up period of 3 years. No signs of fractures within the all-ceramic restorations or symptoms of a temporomandibular disorder were evident. Keywords: infraocclusion, leucite-reinforced glass-ceramic, nonsyndromic oligodontia

Minimally invasive endodontics (MIE) aims to preserve the maximum of tooth structure during root canal therapy. In the last 15 years there has been rapid progress and development in endodontics, making treatment procedures safer, more accurate, and more efficient. Meanwhile, reproducible results can be achieved even in difficult root canal morphologies with severe or double curvatures. In addition to various material improvements, the implementation of the surgical microscope (SM) in endodontics is an important innovation, making it possible to optimize each step in the treatment protocol in terms of substance preservation. Keywords: endodontics, minimally invasive endodontics (MIE), preservation of tooth structure, surgical microscope

Concomitant to the increased use of dental implants to replace lost dentition, there is a growing need to regenerate atrophic jaw bone to allow dental implant placement. Current surgical techniques for jaw bone augmentation share several limitations, such as operator sensitivity and relatively low predictability and high morbidity rates. Therefore, alternative treatment approaches have been developed in the field of tissue engineering. Bone tissue engineering integrates the use of different scaffolds, growth factors, and stem cells. This method aims to induce bone augmentation of large bone defects by mimicking biologic processes that occur during embryogenesis. This review will present available sources for adult stem cells, the rationale for using stem cells for bone regeneration, and recent studies that use mesenchymal stem cells (MSC) and endothelial progenitor cells (EPC) to induce bone augmentation. Keywords: bone augmentation, cell therapy, endothelial progenitor cells, mesenchymal stem cells, regenerative dentistry

Background: Peri-implant disease following successful integration of an endosseous implant is the result of an imbalance between bacterial load and host defense, which may affect not only the peri-implant mucosa but also involve the supporting bone. Objectives: The aim of this study was to evaluate the adjunctive effect of a dental water jet rinse mixed with chlorhexidine gel to the nonsurgical treatment for peri-implantitis. Method and Materials: A prospective randomized interventional cohort study was conducted. Forty consecutive patients presenting with peri-implantitis were recruited and randomly assigned into two treatment groups. Initially all patients received scaling/surface debridement and oral hygiene instruction. Patients in the study group received a water jet device containing chlorhexidine gel (Silonite®) for home use twice daily while the control group performed the recommended oral hygiene measures with no water jet usage. Three months following baseline visit, patients were reevaluated clinically and radiographically. Results: In total, 39 patients completed the study and were available for final examination. Three months following baseline visit the test group exhibited greater mean probing depth reduction (0.75 mm vs 0.27 mm; P = .029) as well as greater reduction in the number of sites presenting with bleeding on probing (2.26 vs 0.45 sites; P = .011). No significant change in bone level was observed at 3 months (mean bone gain was 0.18 mm). Conclusions: Water jet mixed with chlorhexidine gel might supplement the response to nonsurgical treatment for peri-implantitis lesions. Further, larger-cohort studies are warranted. Keywords: bone loss, disinfection, implant threads, peri-implant disease, peri-implant mucositis

The use of dental implants to improve functional and esthetic demands of dentition has increased significantly over the past two decades. Soft and hard tissue management is one of the factors contributing to improved esthetic results. This report describes the correction of an esthetic problem in a single implant combined connective tissue graft and autogenous bone graft. Four months after the surgical procedure, it could be observed that the combination of connective tissue graft and autogenous bone graft resulted in the augmentation of hard and soft tissue in the peri-implant area with favorable esthetic outcomes. Keywords: autogenous bone, connective tissue, dental implants, gingival defect, stage-two surgery

Maxillary sinus elevation has become an important surgical procedure in dental implant surgery. This procedure may induce a variety of postoperative complications including infection, perforation of the sinus membrane, and maxillary sinusitis. However, postoperative infections are relatively infrequent. In this report, an unusual form of infection resulting in a facial skin fistula following maxillary sinus elevation is described. Keywords: complication, dental implant, infection, maxillary sinus elevation

Third molar extraction is one of the most frequently performed procedures in the dental clinic, and it is associated with innumerable trans- and postoperative complications, such as pain, trismus, edema, localized alveolar osteitis, and surgical site infection. Some authors advocate the use of local or systemic antibiotics to reduce the incidence of these postoperative complications. However, several studies have revealed an insignificant gain after using antibiotics. Despite the risks of allergic reactions, toxicity, and the development of resistant microorganisms, about 50% of dentists routinely prescribe the use of prophylactic antibiotics for this purpose. The goal of this paper is to evaluate the scientific evidence that justifies antibiotic prescription to healthy patients undergoing third molar extraction. Keywords: antibiotics, prophylaxis, therapeutics, third molar

Herpes zoster (HZ) infections rarely affect the mandibular branches of the trigeminal nerve. When the mandibular branches are involved, lesions may appear on the face, in the mouth, in the eye, or on the tongue. Additionally, this condition may be associated with devitalized teeth, internal resorption and spontaneous exfoliation of the teeth, and osteomyelitis of the alveolar bone. In this paper, the treatment of a case HZ of the mandibular branch of the trigeminal nerve is reported, and 22 articles on HZ cases with involvement of the mandibular branch are reviewed. This is the first literature review of HZ cases involving only the mandibular branch of the trigeminal nerve. Keywords: herpes zoster, mandible, trigeminal third branch

Objective: The aim of this study was to use cone beam computerized tomography (CBCT), which consistently allowed the determination of the dimensions of the soft tissue, to evaluate acellular dermal matrix grafts (ADMG) used to increase gingival soft tissue thickness (GSTT). Method and Materials: In total, 90 gingival defects were included in the study. Surgical procedures were performed to augment the gingival tissue with ADMG. While GSTT measurements were assessed at baseline and 6, 12, and 18 months post-surgery, ADMG measurements were performed with CBCT at 6, 12, and 18 months post-surgery. Results: All parameters showed statistically significant differences between time intervals. In the ADMG-treated sites, the baseline GSTT was 1.00 ± 0.37 mm and the final thickness was 1.66 ± 0.34 mm. The 6-month measurement of ADMG was 0.79 ± 0.08 mm, and the final measurement was 0.11 ± 0.09 mm. Conclusion: High-quality images of the GSTT and ADMG can be consistently obtained with CBCT. The present findings indicate that soft tissue augmentation can be achieved in gingival defects with the use of ADMG. Keywords: acellular dermal matrix graft, cone beam computerized tomography, gingival augmentation, gingival recession, gingival soft tissue