Comparison of the efficacy of intra-articular injections of hyaluronic acid and lactoferrin in mono-iodoacetate-induced temporomandibular joint osteoarthritis: A histomorphometric, immunohistochemistry, and micro-computed tomography analysis.

OBJECTIVES: This study aims to evaluate the efficacy of high-molecular-weight hyaluronic acid (HMWHA) and lactoferrin (LF) injections on temporomandibular joint (TMJ) cartilage and subchondral bone in mono-iodoacetate (MIA)-induced temporomandibular joint osteoarthritis model in rats. MATERIALS AND METHODS: In this in vivo study, a total of 24 rats were divided into three groups as follows: saline group (Group 1), HMWHA group (Group 2), and LF group (Group 3) including eight rats in each group. The intra-articular injections were administered once a week for three weeks after osteoarthritis was induced. All animals were euthanized 28 days after induction of osteoarthritis, and TMJs were harvested for histomorphometric, immunohistochemical, and micro-computed tomography (CT) analysis. RESULTS: There was no significant difference between the HMWHA and LF groups in terms of the histomorphometric and immunohistochemical analysis results (p>0.05). According to the micro-CT analysis, the LF group had the highest mean bone volume fraction (74.9±0.5) and trabecular thickness (0.122±0.002), while the saline group had the lowest mean values (55.0±0.3 and 0.071±0.002, respectively) (p<0.001). There was no significant difference between the HMWHA and LF groups according to the micro-CT analysis (p>0.05). Both groups had better healing effects than the saline group in all analyses. CONCLUSION: Lactoferrin has a healing effect at least as much as HMWHA in MIA-induced TMJ osteoarthritis. We suggest that LF may be evaluated in future clinical studies as a promising agent in the treatment of osteoarthritis.

Effect of single-dose locally applied lactoferrin on autograft healing in peri-implant bone in rat models.

Immediate dental implant installation into fresh extraction sockets has become a common surgical technique and yields successful clinical results. In addition, complete contact may not be possible with this procedure cause of defects between the bone wall and the implant surface. Therefore, different graft materials have been used in the literature to increase the peri­implant bone volume. The aim of the present study was to evaluate the effect of single-dose and locally applied lactoferrin on autograft healing in peri­implant area and bone implant contact value. Twenty-four Sprague-Dawley rats were included in this study. Firstly, a trephine drill was used for creating a cylindrical bony defects (6.5 mm in diameter and 3 mm in depth) under sterile saline irrigation in the lateral side of the femur. Subsequently, implant beds -2.5 mm diameter and 6 mm depth - were prepared in the middle of each defect with special implant drills. All of the implants were installed and primary stability was achieved. Rats were randomly divided into 3 groups (n = 8 each): Group-1 had empty defects, Group-2 had defects filled with autograft, and Group-3 had defects filled with autograft and lactoferrin solution (100 µg/ml) combination. All of the rats were sacrificed at postoperative 4th week and samples were analyzed with micro-computed tomography, histomorphometry and immunohistochemistry respectively. It was found that Group 3 had the least area of fibrous tissue (6.75±0.83mm2) according to the other 2 groups (p<0.001). On the other hand, Group 3 had the highest osteoblast number (25.50±3.29), osteoclast number (21.25±1.03), newly formed bone area (20.50±1.30 mm2), total healing area (22.62±0.93 mm2), defect closure rate (80.37±1.40%), bone implant contact value (23.2%±0.6%), and percentage bone volume (18.2%±0.3%) (p<0.001). Matrix metalloproteinase-3 expression was found to be highest in Group 3 by immunohistochemistry analysis. In this study it was observed that the results of the different analysis techniques supported each other. According to these findings it can be stated that a single-dose and locally applied lactoferrin solution plays an important role in the autograft healing in peri­implant area and increasing bone implant contact value. These findings will shed light on further clinical studies of implant osseointegration.

Associations between self-reported bruxism, sleep quality, and psychological status among dental students in Turkey.

Objectives: To assess sleep quality among dental students and to identify psychological factors associated with self-reported sleep bruxism (SB).Methods: A total of 212 dentistry students from the Usak University Faculty of Dentistry participated in this study. A self-report questionnaire was administered to identify possible SB. The Depression, Anxiety, and Stress Scale (DASS-21) questionnaire was administered to evaluate psychological factors, and the Pittsburgh Sleep Questionnaire Index (PSQI) was used to evaluate sleep quality.Results: Possible SB was more frequently observed in females than in males. The mean DASS-21 score in those with possible SB was significantly higher than in those without SB (p< 0.001). The mean PSQI (total) score was also significantly higher in those with possible SB than in those without SB (5.0 ± 2.4) (p= 0.007).Conclusion:The findings revealed that psychological factors and sleep quality significantly affected the prevalence of self-reported SB among dental students.