Biomimetic dental implant production using selective laser powder bed fusion melting: In-vitro results.

Instead of a textured surface with irregular pore size and distribution as in conventional dental implants, the use of lattice structures with regular geometric structure and controlled pore size produced by selective laser powder bed fusion melting (LPDF) technique will provide more predictable and successful results regarding osseointegration and mechanics. In this study, biomimetic dental implants with 2 different pore designs were fabricated by LPDF technique and compared with conventional dental implants in terms of surface characterization and resistance to biomechanical forces. Finite element analysis, scanning electron microscopy, computed micro tomography scanning, ISO 14801 tests and detork tests were used for the comparison. The tested biomimetic implants were found to be as durable as conventional implants in terms of mechanical strength and detork values. They were also found to be 40-60% more advantageous than conventional dental implants with respect to surface area and volume. As a result, it was concluded that biomimetic dental implants with sufficient mechanical strength and complex surface geometries can be made as designed without changing the reliable base material and can be produced using a different manufacturing method.

Effect of Systemic Oxytocin Administration on New Bone Formation and Distraction Rate in Rabbit Mandible.

PURPOSE: The main disadvantage of distraction osteogenesis is the prolonged treatment protocol. Recently, oxytocin (OT) has been found to have anabolic effects on bone metabolism. In this experimental study, the effects of OT on the mandibular distraction gap in rabbits at 2 different distraction rates were evaluated. MATERIALS AND METHODS: This experimental study was conducted on 28 male New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group A (control group, n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group B (n = 7) consisted of animals with a distraction rate of 2 mm/day; groups A and B received postoperative saline solution injection. Group C (n = 7) consisted of animals with distraction at a rate of 1 mm/day, and group D (n = 7) consisted of animals with a distraction rate of 2 mm/day; postoperative OT injection was performed in groups C and D. RESULTS: Both histomorphologic and micro-computed tomography evaluations showed increased bone healing in the OT-treated groups. CONCLUSIONS: On the basis of the evaluation of both the histomorphometric and micro-computed tomographic data, systemic OT administration was found to increase new bone formation and bone healing with distraction osteogenesis.

Periodontal ligament cell behavior on different titanium surfaces.

AIM: The purpose of this study was to investigate proliferation, morphology, mineralization and mRNA expressions of mineralized tissue associated proteins of PDL cells on smooth (S), sandblasted small-grit (SSG), sandblasted large-grit (SLG) and sodium titanate (NaTi) coated titanium alloys, in vitro. METHODS AND MATERIALS: PDL cells were cultured with DMEM media containing 10% FBS on the S, SSG, SLG and NaTi titanium surfaces. PDL cell proliferation, mineralization and immunohistochemistry experiments for Bone Sialoprotein (BSP) were performed. The morphology of the PDL cells was examined using confocal and scanning electron microscopy (SEM). Gene expression profiles of cells were evaluated using a quantitative-polymerase chain reaction (Q-PCR) for type I collagen (COL I), Osteocalcin (OCN), osteopontin (OPN) and Runt-related transcription factor-2 (Runx2) on days 7 and 14. RESULTS: Proliferation results on days 6 and 10 were similar in groups, while those of day 13 revealed a decrease in the NaTi group when compared to the S group. NaTi surface induced BSP mRNA expression which was correlated with mineralization tests and BSP immunostaining results. Increased Runx2 mRNA expression was also noted in the NaTi surface when compared to other surfaces. CONCLUSIONS: This study considers the NaTi surface as a potential alternative to SSG and SLG surfaces. This surface might provide a promising environment for PDL ligament-anchored implants.

Development of a visio-haptic integrated dental training simulation system.

The use of haptic devices in the medical field has become widespread in the last decade. In this study, a visio-haptic dental training system is developed using haptic and stereoscopic devices. Several advantages are offered by such a simulation system, including effective learning without any fear of making mistakes on a patient, possibility of repeating various dental operations, ease of evaluating student performance, and low-cost dental training even without an instructor. In this study, the biomechanical properties of enamel, dentin, pulp, and caries were modeled, and the parameters were fine-tuned to provide more realistic haptic sensations. Maxillary and mandibular dental arches and various dental instruments such as mouth mirror, probe, and dental drills were modeled in a 3D virtual environment. Probing and cavity preparation on teeth were implemented in the training system. Various graphical rendering methods (Surface Rendering in CPU, Iso-Surface Rendering, and Ray-Casting in GPU) were implemented and compared in performance. The implementation details and the software structure used are described. Finally, detailed performance tests by a group of dentists are conducted, and the results of these tests are presented. The performance tests found that dentists have a strong motivation to use the system and that in the aspects of usability, clarity, effectiveness, help/support provided, and satisfaction, the users' responses were above average.

Long-term results of arthrocentesis in degenerative temporomandibular disorders.

OBJECTIVES: Long-term efficacy of arthrocentesis was investigated in patients with degenerative temporomandibular disorder (TMD) in this clinical study. STUDY DESIGN: Twenty-two joints of 15 patients with degenerative TMD were included as the study group, and 16 joints of 10 patients served as the control group. Arthrocentesis procedures in upper joint spaces were performed. The study group patients' mean follow-up period was 36.7 +/- 18.7 months, whereas the control group were kept for an average 9.9 +/- 2.8 months. Results were statistically compared using 1-way repeated analysis of variance and t test. RESULTS: Pretreatment maximal interincisal opening increased significantly from 33.6 +/- 6.0 mm to 37.8 +/- 6.0 mm in the study group. Pretreatment pain and crepitus scores decreased significantly from 71.0 +/- 6.6 to 27.0 +/- 16 and 0.73 +/- 0.4 to 0.6 +/- 0.5, respectively, in the study group. CONCLUSIONS: Arthrocentesis was found to be a useful method for the treatment of degenerative TMDs, and the outcomes of treatment provide long-term cure for degenerative temporomandibular joints.