[Study on the Effect of Polystyrene-Polyvinylpyrrolidone Electrospun Fibre in Inhibiting the Adhesion of Porphyromonas gingivalis].

OBJECTIVE: To explore the effect of polystyrene (PS) and PS-polyvinylpyrrolidone (PVP) electrospun materials on the adhesion ability of Porphyromonas gingivalis( P. gingivalis), a common periodontal pathogen. METHODS: PS and PS-PVP electrospun materials were prepared with stainless steel needles in high-voltage electric field. The growth and adhesion of P. gingivalis on the surface of different materials were observed with scanning electron microscope (SEM). The changes in the amount of P. gingivalis biofilm formed on the surface of different materials were measured according to viable colony forming units (CFU). The effect of surface charge of the different materials on the adhesion ability of P. gingivalis was determined through changing the charge properties on the surface of the electrospun materials. RESULTS: SEM images showed that both PS and PS-PVP can be used to form electrospun fibers with a diameter of 0.2 µm. SEM images and CFU counts of the biofilm at 24 h and 48 h showed that there was a smaller amount of P. gingivalis biofilm on the surface of the two materials ( P<0.05). After treatment with tetrabutylammonium bromide (TBAB), the surface charge of the PS-PVP electrospun material changed from being negatively charged to being positively charged, and the amount of bacterial adhesion on the surface increased significantly in comparison to that of untreated PS and PS-PVP materials ( P<0.05). CONCLUSION: PS and PS-PVP electrospun materials can be used to reduce the adhesion ability of P. gingivalis on the surface of different materials, and this ability may be related to the surface charge properties of the materials.

An experimental study addressing the promotion of mandibular defect repair through the intermittent subcutaneous injection of parathyroid hormone.

PURPOSE: Parathyroid hormone (PTH) is a major regulator of bone metabolism. Various animal studies and clinical trials have addressed the treatment of osteoporosis and fracture healing with the intermittent administration of PTH, whereas few studies have investigated the effects of PTH on mandibular defect repair. This study sought to examine the feasibility of using recombinant human PTH (rhPTH) to promote the repair of mandibular defects and to provide a preliminary investigation of the underlying mechanisms of this phenomenon. MATERIALS AND METHODS: A mandibular defect model was established using Japanese white rabbits. The experimental animals were randomly divided into a control group that received postoperative subcutaneous injections of normal saline on alternate days and an experimental group that received postoperative subcutaneous injections of rhPTH 25 µg on alternate days. The experimental animals were sacrificed at 1, 2, 3, and 4 weeks after the operation to perform x-ray imaging and bone histomorphometric examinations of the defect areas. Changes in serum levels of bone-specific alkaline phosphatase (bALP) and osteoprotegerin (OPG) over time were examined. RESULTS: Compared with the control group, the experimental group exhibited newly generated bone matrix in the mandibular defect area at earlier stages. In the experimental group, the bone trabeculae were arranged in an orderly manner, and uniform calcification was observed. Marked hyperplasia of osteoblasts was observed in the new bone tissue of the experimental group, but significantly less hyperplasia of osteoblasts was observed in the control group. In the 2 groups, the average serum bALP and OPG levels increased after the operation and then gradually decreased. In the experimental group, levels of bALP and OPG at 1 week and 2 weeks after the operation were significantly different from preoperative levels. In the control group, the OPG level at 2 weeks after the operation was significantly different from the preoperative OPG level. A comparison of serum bALP and OPG levels at each examined time point showed no significant difference between the 2 groups. CONCLUSION: The intermittent subcutaneous injection of rhPTH 25 µg/day promotes the healing of mandibular defects in rabbits. The application of rhPTH may facilitate mandible regeneration by increasing quantities of osteoblasts, accelerating bone turnover metabolism, and upregulating OPG levels.

Enhancing the inhibition of dental erosion and abrasion with quercetin-encapsulated hollow mesoporous silica nanocomposites.

Introduction: Dental erosion and abrasion pose significant clinical challenges, often leading to exposed dentinal tubules and dentine demineralization. The aim of this study was to analyse the efficacy of quercetin-encapsulated hollow mesoporous silica nanocomposites (Q@HMSNs) on the prevention of dentine erosion and abrasion. Method: Q@HMSNs were synthesized, characterized, and evaluated for their biocompatibility. A total of 130 dentine specimens (2 mm × 2 mm × 2 mm) were prepared and randomly distributed into 5 treatment groups (n = 26): DW (deionized water, negative control), NaF (12.3 mg/mL sodium fluoride, positive control), Q (300 µg/mL quercetin), HMSN (5.0 mg/mL HMSNs), and Q@HMSN (5.0 mg/mL Q@HMSNs). All groups were submitted to in vitro erosive (4 cycles/d) and abrasive (2 cycles/d) challenges for 7 days. The specimens in the DW, NaF, and Q groups were immersed in the respective solutions for 2 min, while treatment was performed for 30 s in the HMSN and Q@HMSN groups. Subsequently, the specimens were subjected to additional daily erosion/abrasion cycles for another 7 days. The effects of the materials on dentinal tubule occlusion and demineralized organic matrix (DOM) preservation were examined by scanning electron microscopy (SEM). The penetration depth of rhodamine B fluorescein into the etched dentine was assessed using confocal laser scanning microscopy (CLSM). The erosive dentine loss (EDL) and release of type I collagen telopeptide (ICTP) were measured. The data were analysed by one-way analysis of variance (ANOVA) with post hoc Tukey's test (α = 0.05). Results: Q@HMSNs were successfully synthesized and showed minimal toxicity to human dental pulp stem cells (HDPSCs) and gingival fibroblasts (HGFs). Q@HMSNs effectively occluded the dentinal tubules, resulting in a thicker DOM in the Q@HMSN group. The CLSM images showed more superficial penetration in the HMSN and Q@HMSN groups than in the quercetin, NaF, and DW groups. The Q@HMSN group exhibited a significantly lower EDL and reduced ICTP levels compared to the other groups (p < 0.05). Conclusion: Q@HMSNs hold promise for inhibiting dentine erosion and abrasion by promoting tubule occlusion and DOM preservation.

A 3-year follow-up clinical study on the preservation for vitality of involved tooth in jaw cysts through an innovative method.

Jaw cysts commonly affect the oral and maxillofacial region, involving adjacent tooth roots. The management of these teeth, particularly regarding root canal therapy and apicoectomy, lacks consensus. This study introduces a novel treatment concept and refined surgical approach to preserve pulp viability in teeth involved in jaw cysts. The objective was to investigate the effectiveness and potential benefits of this approach over a 36-month follow-up period. A conservative management approach prioritized vitality preservation, reserving root canal treatment and apicectomy for cases with post-operative discomfort. A comprehensive follow-up of 108 involved teeth from 36 jaw cyst cases treated with the modified method was conducted. Clinical observation, X-ray imaging, cone-beam computed tomography (CBCT), and pulp vitality testing assessed changes in cyst size, tooth color, pulp vitality, root structure, and surrounding alveolar bone. After 36 months, our modified surgical approach successfully preserved tooth vitality in 84 involved teeth. Adverse symptoms in 19 teeth, such as redness, swelling, fistula, and pain, resolved with postoperative root canal therapy. Follow-up was lost for five teeth in two cases. No cyst recurrences were observed, and in 34 cases, the bone cavity gradually disappeared, restoring normal bone density during long-term follow-up. Our modified surgical method effectively preserves tooth vitality in jaw cysts. This innovative approach has the potential to improve the management of teeth involved in jaw cysts.

[Application of computer virtual design to assist the accuracy of socket preparation during tooth autotransplantation].

PURPOSE: It was aimed to apply computer virtual design and digital surgical templates to simulate postoperative position of tooth and guide the accuracy of socket preparation during tooth autotransplantation. METHODS: The study enrolled 10 patients who underwent tooth autotransplant surgery. Cone-bean CT (CBCT) data were imported into Proplan CMF 3.0 software. The donor tooth was transferred to the recipient site according to the occlusion and space situation. A digital template was designed to guide socket preparation. Computer-aided rapid prototyping (RP) technique was used to print the surgical template and tooth model. RESULTS: With computer virtual design and digital template, it was possible to accurately guide socket preparation in recipient site. The six-month follow-up results showed the periodontal space in the radiographs was continuous and intact. There was no mobility in all cases and the probing depth of the tooth was <4 mm. The related data showed a favorable survival and success rates of the donor teeth. CONCLUSIONS: Computer virtual design can successfully simulate postoperative position in tooth autotransplantation while simplifying the surgical procedure, and enhance the accuracy of socket preparation.

Long-term follow-up of a patient with venlafaxine-induced diurnal bruxism treated with an occlusal splint: A case report.

BACKGROUND: Bruxism is a jaw-muscle activity characterized by the clenching or grinding of teeth. It can be divided into nocturnal bruxism and diurnal bruxism (DB). DB secondary to antidepressants is rare and refractory. Reports associated with antidepressant-induced DB are mostly anecdotal without long-term follow-up. The effect of drug intervention on antidepressant-induced DB is still contested. We herein report the first case of successful treatment of venlafaxine-induced DB with an occlusal splint. CASE SUMMARY: This case report describes detailed 7-year follow-up of a patient with venlafaxine-induced DB treated with an occlusal splint. The patient who complained about involuntary daytime tooth grinding after taking venlafaxine for a period of 4 mo and was diagnosed with venlafaxine-induced DB. Subsequently, an occlusal splint with modified bilateral buccal-pterygoid pads was used to treat his tooth grinding and to protect the dental structures from tooth wearing. The patient reported remission of symptoms after several months of treatment. His grinding activity was gradually and stably controlled after 2 years, with an almost complete recovery from DB after 6 years. CONCLUSION: The maxillary buccal-pterygoid splint can be used as a noninvasive approach to treat venlafaxine-induced DB.

[Evaluation of using Proplan virtual software in teaching of orthognathic surgery].

PURPOSE: Using Proplan virtual software to construct a virtual teaching platform for orthognathic surgery, and to explore an effective teaching model for orthognathic surgery. METHODS: One-hundred grade four students of stomatology in Fujian Medical University were divided into two groups. Traditional orthognathic surgery teaching method and Proplan virtual software teaching method were employed to teach the two groups of students, respectively. Orthognathic-surgery-related paper test was used to evaluate how the two groups of students understand orthognathic surgery; then the students were switched to the other teaching method, respectively. A follow-up questionnaire survey was conducted to further evaluate students' acceptance of the two teaching methods. Finally, a comprehensive statistical analysis was performed for students understanding of orthognathic surgery using SPSS 11.0 software package. RESULTS: According to the test scores, students in the experimental group scored higher than the control group, the difference was significant (P<0.01). The acceptance of different teaching methods displayed remarkable difference between the two groups. Token together, our finding showed that virtual model surgery teaching was an easier teaching method for students to understand and accept. CONCLUSIONS: Proplan virtual software teaching improves the teaching efficiency of orthognathic surgery and deserves further promotion.

[Clinical effect of modified alveolar cleft repair with bone grafting].

PURPOSE: To evaluate the clinical effect of improved alveolar cleft repair with bone grafting. METHODS: Forty one cases with alveolar cleft treated by modified operation between 2008-2016 were included. The modified techniques were as follow: incision design, preparation of bone graft bed, bone removal and bone grafting, etc. The therapeutic effect was analyzed. RESULTS: The successful rate was 92.8%. After 6-12 months of follow-up, bone graft survived well with no obvious complications. CONCLUSIONS: Iliac bone is a good source for bone graft. Improvement of tight tension-free suture in bone bed is the key to surgical success.