Immediate implant placement for chronic peri-apical periodontitis in the molar region: a randomised controlled trial.

The aim of this study was to evaluate the feasibility of immediate implantation for chronic peri-apical periodontitis in the molar region. Seventy-four molars were selected and allocated randomly to two groups. The experimental group (n = 38) received immediate implantation by flap surgery and the control group (n = 36) received delayed implantation. CBCT was performed immediately after surgery (T1) and 12 months after the permanent repair (T3). The implant survival rate at T3 was 100% in both groups. There was no significant difference in buccal or lingual vertical marginal bone loss between the groups (P = 0.515, P = 0.736). However, the buccal horizontal margin bone loss was significantly greater in the experimental group: 0.98 ± 0.34 mm vs 0.77 ± 0.27 mm in the control group (P = 0.003). In the experimental group, the highest point of buccal and lingual implant-bone contact increased at T3. The buccal and lingual jump gap widths were 3.21 ± 1.10 mm and 2.92 ± 1.01 mm at T1, and CBCT showed no jump gap around the implants at T3. The clinical outcomes showed immediate implantation to be feasible for chronic peri-apical periodontitis in the molar region.

[Clinical effect and analysis of exercise treatment for temporomandibular joint osteoarthritis].

Objective: To explore the clinical efficacy of (stomatognathic system functional exercise(SSFE) in the treatment of temporomandibular joint osteoarthritis (TMJOA), and to provide reference for the clinical treatment of TMJOA. Methods: Choose between January 2020 and June 2020 in the Affiliated Hospital of Qingdao University of Temporomandibular Disorder (TMD) Clinics, pain in the temporomandibular joint (TMJ), limited openings for complained of symptoms of TMD patients, diagnosed by clinical examination and cone beam CT (CBCT) examination of TMJOA patients 60 patients (64 joints), including 20 males and 45 females, the age was (42.6±2.5) years (33-47 years old). The patients were randomly divided into the experimental group (30 cases, 34 joints) and the control group (30 cases, 30 joints) according to the odd and even numbers of their treatment numbers. The experimental group was treated with SSFE method. The control group was treated with maxillary full dentition occlusal splint. Visual analogue score (VAS), natural mouth opening and maximal mouth opening (MMO) of each patient in each group were recorded at initial diagnosis, 2 weeks, 3 and 6 months after treatment, and CBCT imaging was compared for the changes of condylar bone at initial diagnosis, 3 and 6 months after treatment. Results: VAS values of the experimental groups were (2.90±1.42), (0.90±0.37), (0.87±0.23) at 2 weeks, 3 and 6 months after treatment, respectively. The VAS values of the control group were (4.57±1.94), (4.17±2.09), (3.73±2.21), respectively. The VAS score of the experimental group was significantly lower than that of the control group (F=42.93, P<0.001). Before SSFE treatment, all the patients in the experimental group had different degrees of restricted opening and characteristic abnormal opening and closing pattern. Two weeks after SSFE treatment, the opening degree of the patients was (37.69±2.4)mm, the opening shape "↓" and the closing shape "↑" were normal. At 3 and 6 months after treatment, the oral opening was (38.98±1.08) mm and (39.73±1.76) mm, respectively. The opening degree of control group was (36.85±2.33) mm 2 weeks after treatment, and the characteristic abnormal opening and closing pattern still existed. The opening degree of control group was (37.82±1.85) mm and (37.40±1.75) mm 3 and 6 months after treatment, respectively. The characteristic abnormal opening and closing pattern (stuffy, awkward, deliberate, unnatural) did not improve significantly. The openness of the experimental group was significantly higher than that of the control group (F=25.20, P<0.001). In the experimental group, 82.4% (28/34) had benign remodeling of condylar bone 6 months after treatment, and 17.6% (6/34) had no change of condylar bone. There was no significant change in condylar bone in control group. CBCT scores of the experimental group were (2.43±1.74) and (1.70±1.26) at 3 and 6 months after treatment, respectively. CBCT scores of the control group at 3 and 6 months after treatment were (4.23±1.50) and (4.10±1.37), they were significantly lower in the experimental group than in the control group (F=27.20, P<0.001). Conclusions: Full dentition occlusal splint can alleviate the pain in the joint area of TMJOA patients, but can not improve the characteristic abnormal mandibular movement, and the condyle bone repair is not obvious. SSFE can effectively relieve the symptoms and signs of TMJOA patients, especially improve the abnormal characteristic mandibular movement, and promote the normal reconstruction and repair of condylar bone.

A magnetic resonance imaging study on the temporomandibular joint disc-condyle relationship in young asymptomatic adults.

The aim of this study was to assess the temporomandibular joint (TMJ) disc-condyle relationship in asymptomatic young adults. Ninety-three volunteers aged 19-23 years without temporomandibular disorder (TMD) symptoms underwent TMJ magnetic resonance imaging (MRI). The condylar centre and apex methods were used to measure and analyse the position of the disc in the oblique sagittal plane, and the reliability of the two methods was compared by calculating the intra-class correlation coefficient (ICC). Furthermore, 18 of the volunteers were randomly selected for three-dimensional (3D) reconstruction of the TMJ structure and the disc-condyle relationship. The 3D TMJ structure was established by semi-automatic segmentation of the condyle and articular disc in ITK-SNAP software; the condylar apex method was then performed. It was found that only 33.3% of the posterior edge of the articular discs were located in the normal 12 o'clock position with respect to the condyle. Moreover, this study suggests that the condylar centre method lacks accuracy when compared to the condylar apex method in regard to the measurement of the TMJ disc-condyle relationship (0 < ICCcen < ICCapex < 1). The position of the articular disc (left and right) was more forward in young women when compared to young men. However, there was no significant difference in the TMJ disc-condyle position between the left and right sides in the same individual, although the two joint discs in the same individual were not completely symmetrical.

Airy beams generated by a binary phase element made of polymer-dispersed liquid crystals.

Using polymer-dispersed liquid crystals (PDLCs), an electrically switchable binary phase pattern was fabricated to generate Airy beams through a programmable lithographic system. The right main lobe of the reconstructed Airy beam experienced 1.3 mm transverse deflection within 24 cm propagation distance. With a suitable voltage applied, the binary PDLC pattern can be erased due to the index match between polymers and liquid crystals. This versatile approach can be also used to generate other special beams with electrically tunable capability.

Condylar positions before and after bilateral mandibular distraction osteogenesis in children with Pierre Robin sequence.

This study aimed to analyze the changes in mandibular morphology after bilateral mandibular distraction osteogenesis (BMDO) in children with Pierre Robin sequence. The positions of the condyles were analyzed in reconstructed three-dimensional craniomaxillofacial images obtained for 18 children before and 8-12 weeks after BMDO. Differences between pre- and postoperative parameters were assessed using paired t-tests. After surgery, a significant decrease in superior joint space was detected (P<0.05), but no change in anterior joint space or posterior joint space was observed. The ratio of the distance between gonia and distance between condylion points (GoL-GoR/CoL-CoR) (P<0.001) and the distances between the condyle and midsagittal plane (P<0.001) increased after surgery, while the condylar horizontal angle decreased (P<0.05). No change in condylar vertical angle was noted. After BMDO, the condyle displayed an outward and upward shift, as well as outward rotation along the proximal segment. The mandible body exhibited forward movement with a more significant opening range. These changes were consistent with the extent of the newly formed bone tissue and the improvement in coordination and appearance of the children's facial structures. The long-term effects of changes in condylar position on the development of the maxillofacial structures needs to be studied further.

Quasi-static acoustic tweezing thromboelastometry.

Essentials Blood coagulation measurement during contact with an artificial surface leads to unreliable data. Acoustic tweezing thromboelastometry is a novel non-contact method for coagulation monitoring. This method detects differences in the blood coagulation state within 10 min. Coagulation data were obtained using a much smaller sample volume (4 µL) than currently used. SUMMARY: Background Thromboelastography is widely used as a tool to assess the coagulation status of critical care patients. It allows observation of changes in material properties of whole blood, beginning with early stages of clot formation and ending with clot lysis. However, the contact activation of the coagulation cascade at surfaces of thromboelastographic systems leads to inherent variability and unreliability in predicting bleeding or thrombosis risks. Objectives To develop acoustic tweezing thromboelastometry as a non-contact method for perioperative assessment of blood coagulation. Methods Acoustic tweezing is used to levitate microliter drops of biopolymer and human blood samples. By quasi-statically changing the acoustic pressure we control the sample drop location and deformation. Sample size, deformation and location are determined by digital imaging at each pressure. Results Simple Newtonian liquid solutions maintain a constant, reversible location vs. deformation curve. In contrast, the location/deformation curves for gelatin, alginate, whole blood and blood plasma uniquely change as the samples solidify. Increasing elasticity causes the sample to deform less, leading to steeper stress/strain curves. By extracting a linear regime slope, we show that whole blood or blood plasma exhibits a unique slope profile as it begins to clot. By exposing blood samples to pro- or antithrombotic agents, the slope profile changes, allowing detection of hyper- or hypocoagulable states. Conclusions We demonstrate that quasi-static acoustic tweezing can yield information about clotting onset, maturation and strength. The advantages of small sample size, non-contact and rapid measurement make this technique desirable for real-time monitoring of blood coagulation.

[Positions of the implanted stimulating electrodes for artificial facial nerve for inducing contraction of the orbicularis oris muscle in rabbit with peripheral facial paralysis].

Objective: To explore the optimal positions of the implanted stimulating eletrodes for artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the four microelectrodes of the AFN stimulating side, four modes of the implanted positions were divided. In line with different modes, the electrodes were implanted into the affected OOM of the rabbits with unilateral peripheral facial paralysis. AFN output electric stimulation to induce contraction of the affected OOM with uniform stimulating frequency and pulse length in vitro. Then compared the stimulus threshold amplitude and the peak amplitude separately among different modes by SAS 9.3 version statistical software. Results: The differences of the stimulus threshold amplitude and the peak amplitude had no statistically significant separately between the first mode and the second mode (P>0.05), but there were statistically significant differences between the third mode and the fourth mode (P<0.05). Both kinds of the amplitudes were approximated between the first mode and the second mode respectively, and higher than those in the third mode or the fourth mode. Furthermore, both kinds of the amplitudes in the fourth mode were higher than those in the third mode. Conclusions: The microelectrodes of the AFN stimulating lateral are implanted into the upper lip with a public microelectrode and an output microelectrode, into the lower lip with an output microelectrode, and into the way, which is located to the angle 40° to 45° about the line joining between the midpoint of the ipsilateral auricle root and the corner of the mouth with an output microelectrode. This is the third positional mode which requires lowest effective stimulus current intensity. Thus the mode is suitable as the optimal placement programme.

Use of encapsulated single chain antibodies for induction of anti-idiotypic humoral and cellular immune responses.

The use of biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres as a cancer vaccine delivery system for induction of anti-idiotypic responses has been investigated using a single chain antibody scFv-pDL10, which recognizes the human ovarian cancer antigen CA125. Immunization of mice with scFv-pDL10 encapsulated in PLGA microspheres resulted in enhanced humoral and cellular immune responses when compared to scFv-pDL10 alone. Induced anti-idiotypic antibodies (Ab2) which mimic the original antigen CA125 compete with CA125 for the epitope. A cellular response (T2 induction) was also observed. These results raise the possibility of anti-idiotypic antibody induction by a single chain antibody, encapsulated in biodegradeble microspheres, as a potential vaccine for ovarian carcinoma.

Caries inhibition efficacy of an antiplaque/antigingivitis dentifrice.

PURPOSE: To evaluate the efficacy of a fluoride dentifrice containing a fixed combination of essential oils (Thymol, Menthol, Eucalyptol, and Methyl Salicylate) in preventing caries in Sprague Dawley rats. MATERIALS AND METHODS: The dentifrice contains 0.76% sodium monofluorophosphate (SMFP) as the fluoride source and a silica abrasive system. A fluoride-free placebo and a clinically proven USP dentifrice reference standard for SMFP/silica were included as controls. Three groups of 45 SDV-free Sprague Dawley weanlings were infected by a cariogenic strain of Streptococcus sobrinus and fed cariogenic diet NIH 2000 ad libitum. Animals were treated twice daily (once on weekends) with the assigned dentifrice using a cotton-tipped applicator, for 5 wks, after which they were terminated and caries scored using Larson's modification of the Keyes method. RESULTS: Analyses of variance were used to compare inter-group means, the total E lesion score was the primary efficacy variable. Compared with the fluoride-free vehicle control, the experimental dentifrice and USP reference standard dentifrice produced a statistically significant reductions of 18.3% and 12.2% respectively for total caries score (P<0.001). Compared with the clinically tested USP positive control dentifrice, the experimental dentifrice produced a statistically significant reduction in the total caries score of 6.9% (P=0.028). The results of this study show that 1) both the new dentifrice containing essential oils and USP dentifrice are statistically significantly effective in reducing caries in the rat model, 2) the anticaries activity of the SMFP dentifrice is not adversely affected with the addition of essential oils.

Stain removal efficacy of two new fluoride dentifrices containing essential oils.

PURPOSE: To assess in vitro the stain removal efficacy of two new antiplaque/antigingivitis dentifrices utilizing a modification of a previously validated Stookey method. MATERIALS AND METHODS: The modifications to the original Stookey method are the following: (1) study design; three 5 x 5 Latin Squares were employed to minimize bias stemming from position or test run in the study. (2) statistical success criteria; a test formulation was judged to be effective if the lower one-sided 95% confidence limit was "equal to or higher than" 50 since a minimum PCR (pellicle cleaning ratio) score of 50 is needed for a dentifrice to show clinical efficacy. The two test dentifrice formulations contained a fluoride source, a silica abrasive system, and four essential oils. The ADA reference abrasive material (calcium pyrophosphate) and placebo toothpaste were included as positive and negative controls, respectively. RESULTS: Compared to the negative control, the positive control exhibited a statistically higher PCR score; therefore, the validity of this modified Stookey method was confirmed. Additionally, the lower limits of the one-sided 95% confidence interval for the two dentifrice formulations were above the threshold PCR of 50; therefore, this modified Stookey method should predict that both essential oil-containing dentifrices possess acceptable stain removal power.

[A study on the treatment and restoration of the complete fractured teeth].

In order to keep the fractured teeth with their important function of mastication the authors had adopted a kind of improved calvital preparation to carry out the pulp treatment for 56 cases, 63 teeth, together with periodontal washing, the application of medicine and the periodontal treatment of gingivectomy and flap operation, etc. from Jan. 1989 to Jan. 1993. The regularization of the filling of the fragmental area, the combination and the fixation of the split tooth were strengthened with spiral root post and dentin retaining nails, and then the full cast crown was restorated. The results were satisfied. It turns out that complete fracture of posterior teeth, thought to be pulled out in the past because they had split well below the gum, or even affected the pulp chamber floor, can be kept if given treatment and proper restoration.

Response of human femur to mechanical vibration.

The effect of mechanical vibration in the frequency range 0-500 Hz on the cadaveric human femur was assessed. It was found that when the bone was fixed at both ends, its resonant frequency was markedly affected by end loading and damping. If the conditions of the experiment were designed to simulate the condition of the femur when prepared for a total hip replacement, it was found that the bone did not resonate but behaved in a mass-like mode. The significance of this observation is that in the event of vibration being applied to enhance the penetration of bone cement, the movement induced in the bone will be proportional to the force applied regardless of frequency. This also demonstrates that the concept of designing a prosthesis so that it is isoelastic with the femur is complex and potentially flawed, since the stiffness of the femur will vary during the walking cycle.

Antitumor effect of the idiotypic cascade induced by an antibody encapsulated in poly(d,l-lactide-co-glycolide) microspheres.

A major difficulty encountered during development of antibody vaccines is their weak immunogenicity. In this study, a monoclonal antibody CS20.5 to human breast cancer antigen CA15.3 was coencapsulated in poly(d,l-lactide-co-glycolide) microspheres with monophosphoryl lipid A. The antitumor effect of this formulation was investigated in a murine model. The induced Ab2 biologically mimics antigen as it competed with CA15.3 for the same idiotope on Ab1. Ab3 induction was also observed. After five sequential administrations of encapsulated antibody, mice showed statistically significant tumor regression. These results indicate that this formulation may serve as a potential treatment for breast cancer.

Controlled DNA delivery systems.

PURPOSE: Genes are of increasing interest as pharmaceuticals, but current methods for long-term gene delivery are inadequate. Controlled release systems using biocompatible and/or biodegradable polymers offer many advantages over conventional gene delivery approaches. We have characterized systems for controlled delivery of DNA from implantable polymer matrices (EVAc: poly (ethylene-co-vinyl acetate)) and injectable microspheres (PLGA and PLA: poly (D, L-lactide-co-glycolide) copolymer and poly (L-lactide), respectively). METHODS: Herring sperm DNA and bacteria phage lambda DNA were encapsulated as a model system. Released DNA concentration was determined by fluoroassays. Agarose electrophoresis was used to determine the dependence of release rate on DNA size. The Green Fluorescent Protein (GFP) gene was used to determine the integrity and functionality of released DNA. RESULTS: Both small and large DNA molecules (herring sperm DNA, 0.1-0.6 kb; GFP, 1.9 kb; lambda DNA, 48.5 kb) were successfully encapsulated and released from EVAc matrices, and PLGA or PLA microspheres. The release from DNA-EVAc systems was diffusion-controlled. When co-encapsulated in the same matrix, the larger lambda DNA was released more slowly than herring sperm; the rate of release scaled with the DNA diffusion coefficient in water. The chemical and biological integrity of released DNA was not changed. CONCLUSIONS: These low cost, and adjustable, controlled DNA delivery systems, using FDA-approved biocompatible/biodegradable and implantable/injectable materials, could be useful for in vivo gene delivery, such as DNA vaccination and gene therapy.