OBJECTIVETo obtain dental restorations by machining PMMA-ZrO2 organic-inorganic composites with the dental CAD/CAM system.

METHODSPartially sintered Zirconia compacts (PSZC) were prepared via isostatic pressing and partially sintering, with Zirconia nanopowder as raw materials. PMMA-Zirconia organic-inorganic composites were prepared by vacuum infiltrating the prepolymerized MMA into the PSZC, followed by in-situ polymerization. The mechanical properties and machinability of composites were studied. The composites were machined on the dental CAD/CAM system to obtain dental restoration.

RESULTSAt 71.44% TD of PSZC, the composite had a 3-point bending strength of (202.56 +/- 3.09) MPa, fracture toughness of (4.30 +/- 0.16) MPa.m(1/2), elasticity modulus of (58.71 +/- 1.98) GPa, and Vickers hardness of (3.82 +/- 0.34) GPa, respectively. A premolar crown was fabricated by CAD/CAM system in 16 mins, and was verisimilitude, without any cracks.

CONCLUSIONSThe composite at 71.44% TD of PSZC has good mechanical properties and dental restorations can be manufactured by PMMA-Zirconia composites via dental CAD/CAM system.

Computer-Aided Design ; Dental Materials ; Dental Prosthesis ; Materials Testing ; Polymethyl Methacrylate ; therapeutic use ; Zirconium ; therapeutic use

Bone cement, consisting of polymethyl methacrylate, is a bioinert material used for prothesis fixation in joint arthroplasty. To treat orthopedic infections, such as periprosthetic joint infection, antibiotic-loaded bone cement (ALBC) was introduced into clinical practice. Recent studies have revealed the limitations of the antibacterial effect of ALBC. Moreover, with the increase in high infection risk patients and highly resistant microbes, more researches and modification of ALBC are required. This paper reviewed latest findings about ALBC for most popular and destructive pathogens, summarized the influence of antibiotic kind, drug dosage, application method, and environment towards characteristic of ALBC. Subsequently, new cement additives and clinical applications of ALBC in joint arthroplasty were also discussed.
Anti-Bacterial Agents/therapeutic use* ; Arthroplasty, Replacement, Knee ; Bone Cements ; Humans ; Polymethyl Methacrylate ; Prosthesis-Related Infections/drug therapy*

Polymethl methacrylate (PMMA) screw reinforcement is frequently used in osteoporotic bone as well as in damaged pilot holes. However, PMMA use can be dangerous, since the amount of applied cement is uncontrolled. A 47-year-old male with traumatic cervical spondylolisthesis at C6-7 underwent anterior cervical plate fixation. During repeated drilling and tapping for false trajectory correction, a pilot hole was damaged. Although it was an unconventional method, PMMA augmentation was tried. However, PMMA was accidentally injected to the cervical spinal cord owing to lack of fluoroscopic guidance. The PMMA was surgically removed after corpectomy and durotomy. The patient had left side hemiparesis (Grade 2/5) immediately post operation. The patient improved spontaneously (Grade 4/5) except for 4th and 5th digit extension. Here, we report a rare complication of PMMA extrusion in the spinal cord during a damaged pilot hole injection, which has not previously been described.
Bone Cements/*adverse effects/therapeutic use ; Bone Screws ; Cervical Vertebrae/*surgery ; Humans ; Male ; Middle Aged ; Polymethyl Methacrylate/adverse effects/therapeutic use

OBJECTIVETo compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system (PS) in the treatment of vertebral compression fracture(VCF).

METHODSEighty-six patients with VCF were treated either by PKP (Group A, n equal to 30) or PS (Group B, n equal to 56). The anterior, intermediate, and posterior heights of the vertebrae body, visual analogue pain scale (VAS) before and after operation, the duration of operation, and amount of blood loss between two groups were compared.

RESULTSNo statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS, duration of operation and amount of blood loss between the two groups (P less than 0.01).

CONCLUSIONSPercutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion, less operation time and blood loss. For those with posterior wall destruction, PS is deemed favorable.

Adult ; Aged ; Bone Cements ; therapeutic use ; Bone Screws ; Female ; Fractures, Compression ; therapy ; Humans ; Internal Fixators ; Male ; Middle Aged ; Orthopedic Procedures ; Polymethyl Methacrylate ; therapeutic use ; Spinal Fractures ; therapy

OBJECTIVE: To investigate the clinical efficacy of acrylic cement (PMMA) mixed with calcium sulfate combined with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic fracture (OVCF). METHODS: The clinical data of 191 patients with OVCF treated with PKP from January 2020 to March 2021 were retrospectively analyzed. Among them, 82 patients with 94 vertebral bodies were treated with PMMA mixed with calcium sulfate as the observation group, and 109 patients with 125 vertebral bodies were treated with pure PMMA as the control group. Among the 82 patients in the observation group, there were 16 males and 66 females, with a mean age of (75.35±11.22) years old, including 36 thoracic vertebrae and 58 lumbar vertebrae. In the control group, there were 109 patients, 22 males and 87 females, with an average age of (74.51±9.21) years old, including 63 thoracic vertebrae and 62 lumbar vertebrae. The visual analog scale (VAS) before operation and 1 day, 3 months and 1 year after operation were calculated. The Oswestry disability index (ODI), Cobb's angle, vertebral body height and the probability of postoperative bone cement leakage were used to analyze the efficacy of the two groups. RESULTS: All the patients were followed up for more than one year. Compared with the control group, there was no significant difference in operation time, bleeding volume and bone cement injection volume between the two groups(P>0.05), while the leakage rate of bone cement was significantly lower in the observation group (P<0.05). In addition, there was no significant difference in VAS, ODI, Cobb angle, and vertebral body height between the two groups before operation, and 1 day, 3 months, and 1 year after operation (P>0.05), but each index was improved compared with that before operation (P<0.05). CONCLUSION PMMA mixed with calcium sulfate has equivalent efficacy in treating OVCF than PMMA alone, but can effectively reduce the probability of cement leakage.
Female ; Male ; Humans ; Aged ; Aged, 80 and over ; Middle Aged ; Polymethyl Methacrylate ; Calcium Sulfate/therapeutic use* ; Osteoporotic Fractures/surgery* ; Bone Cements/therapeutic use* ; Kyphoplasty ; Retrospective Studies ; Lumbar Vertebrae/surgery*

BACKGROUNDA number of methods have been used in the treatment of symptomatic and aggressive vertebral hemangioma, but none of them is optimal. Vertebral hemangioma treated with cement vertebroplasty or ethanol injection alone showed relatively good results despite their limitations.

METHODSBetween February 2002 and May 2004, twelve patients with vertebral hemangioma were subjected to combined cement vertebroplasty and ethanol injection, five of them were men and seven women, and aged from 26 to 54 years (mean, 41 years). The following levels of the spine were involved: T9: 1, T10: 3, T12: 2, L1: 1, L2: 2, L3: 2 and L4: 1. The clinical results and radiographic records of the patients were assessed after 2 years and 5 months of follow-up.

RESULTSThe average score of back pain significantly decreased from 6.5 before operation to 1.7 one month after operation. No severe complications occurred during and after operation. During the period of follow-up, symptoms were not deteriorated. At the end of follow-up, neither radiographic sign of aggressive destruction nor collapse of the involved vertebra was observed. Significant improvement in the 12 patients was demonstrated on 7 of 8 SF-36 Health Scale except for mental health.

CONCLUSIONSCement vertebroplasty combined with ethanol injection as a safe and effective technique is an alternative to the treatment of patients with vertebral hemangioma.

Adult ; Bone Cements ; therapeutic use ; Combined Modality Therapy ; Ethanol ; administration & dosage ; Female ; Hemangioma ; therapy ; Humans ; Injections ; Male ; Middle Aged ; Polymethyl Methacrylate ; Spinal Neoplasms ; therapy ; Spine ; surgery

BACKGROUNDPercutaneous vertebroplasty (PVP) has become a popular procedure for painful vertebral osteoporotic fracture (VOF), with immediate pain relief and improved mobility; however, polymethylmethacrylate (PMMA) injected into the vertebral body is not absorbable and little information is available concerning the long-term results. In this retrospective study, we evaluated the long-term clinical results and radiological changes after PVPs for VOFs.

METHODSFifty-one patients with VOFs were treated by PVPs with PMMA between 2000 and 2004. After > 7 years of follow-up, eight patients had died from causes unrelated to the intervention and 12 patients were lost to follow-up, thus leaving 31 patients available for evaluation with an average length of follow-up of 9.2 years (follow-up rate, 72.1%). Among these 31 patients, the PMMA was injected at 43 levels with a mean volume of 4.3 ml per level (range, 2 - 6 ml). The pain was assessed with a visual analog scale (VAS), and the mobility was graded as walking without difficulty (grade 1), walking with assistance (grade 2), and bedridden (grade 3). Plain radiographs and computed tomography (CT) were obtained and assessed pre-operatively, immediately post-operatively, and after 7 years of follow-up. The PMMA, vertebral height, and Cobb angle were assessed and compared.

RESULTSAll of the patients experienced pain relief and improved mobility after intervention and during the follow-up period. Cement leakage was detected in post-operative CT scans in 9 of 51 patients, but without neurological compromise. For the 31 patients followed up over 7 years, the VAS decreased from 8.3 ± 2.6 pre-operatively, to 2.1 ± 1.6 immediately post-operatively, and 1.0 ± 0.9 at the final follow-up evaluation, with significantly improved mobility. Additional compression fractures occurred at adjacent levels in three patients, and there were no new fractures at the augmented vertebrae. Based on a review of the radiographs, neither loose nor displaced cement was detected. The changes in vertebral height and Cobb angle were not significant. On CT scans, the cement closely contacted or infiltrated the trabecular bone. The boundary between the cement and trabecular bone was indistinct and there was no evident radiolucent gap between the cement and trabecular bone.

CONCLUSIONSAt an average follow-up of 9.2 years, PVPs provided sustained pain relief and improved mobility in patients with VOFs. The PMMA injected into the vertebral body combined closely with the host trabecular bone without adverse reactions.

Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Osteoporotic Fractures ; surgery ; Polymethyl Methacrylate ; therapeutic use ; Retrospective Studies ; Spinal Fractures ; surgery ; Vertebroplasty ; methods

OBJECTIVETo evaluate the influence of naringin on PMMA-induced osteoclastic bone resorption using the mouse air sacs model.

METHODSTotal 48 female Balb/c mices with the age of 8 to 10 weeks were chosen in the study. Air were injected into the back in 32 mices and formed the air sacs, 6 d later, the skulls (originated from other 16 mices) were implanted to the air sacs. Thirty-two animals were divided into naringin treatment group (with 2 concentrations of 150 mg/kg and 30 mg/ kg) , DMSO group and PBS blank group, 8 animals in each group. Polymethylmethacrylate (PMMA) particles were injected into the air sacs in naringin treatment groups and DMSO group so as to irritate inflammatory reaction. Naringin with 2 concentrations of 150 mg/kg and 30 mg/kg were dissolved in DMSO of 0.2 ml, and were injected into air sacs, respectively. In PBS black group, no stimulation with PMMA particles, only injected PBS, and in DMSO group, injected DMSO without naringin. Tartrate resistant acid phosphatase (TRAP), Ca2+ release, modified Masson stain and histological analysis were performed on the 7th day after stimulation.

RESULTSCompared with DMSO group, naringin treatment group's cellular infiltration decreased (P < 0.01); concentration of 150 mg/kg was better than that of concentrations of 30 mg/kg (8.90 ± 1.75 vs 15.23 ± 1.86). Naringin can decrease calcium release in the lavage of the air sacs bone resorption model, especially obvious in naringin with concentration of 150 mg/kg. Naringin can ameliorate the inflammatory reaction and the subsequent bone resorption (including bone collagen loss, TRAP positive cells amount and so on) in air sacs with bone implant and PMMA particles. Naringin with concentration of 150 mg/kg appeared to be an optimal dosage to deliver the therapeutic effects.

CONCLUSIONNaringin inhibits PMMA-induced osteoclastogenesis and ameliorates the PMMA-associated inflammatory reaction and the subsequent bone resorption.

Animals ; Disease Models, Animal ; Female ; Flavanones ; therapeutic use ; Mice ; Mice, Inbred BALB C ; Osteoclasts ; drug effects ; physiology ; Osteolysis ; chemically induced ; prevention & control ; Polymethyl Methacrylate ; toxicity

OBJECTIVETo discuss the effect and complication of spinal operation combined with vertebroplasty in treating for multiple spinal neoplasm.

METHODSDuring the last two years, 20 patients (13 male and 7 female) with multiple spinal neoplasm including metastases, multiple myeloma and lymphoma were treated by operation combined with vertebroplasty, 2 vertebral body segments were involved in 5 cases, 3 to 4 vertebral body segments were involved in 11 cases, more than 5 segments were involved in other 4 cases. Neurological function deficit and severe pain were seen in all the cases. Patients were evaluated by Tomita prognostic scoring system before the operation; The average point was 7.2 (from 3 to 9 points).

RESULTSThe pain relief rate was 85% (17/20), and neurological recovery was found in 10 out of 12 patients who had neurological deficit. According to the system of Frankel and neurological function, 1 patient recovered from grade B to grade C after the operation, and there was no change in another patients who was evaluated as grade A before the operation. The main complication of vertebroplasty was leakage of PMMA. Six patients had leakage of PMMA into adjacent structures in this series.

CONCLUSIONSBetter results of pain relief and neurological function recovery and living quality can be achieved by surgical palliation of operation combined with vertebroplasty for multiple spinal neoplasm.

Adult ; Aged ; Bone Cements ; therapeutic use ; Combined Modality Therapy ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Multiple Myeloma ; surgery ; Polymethyl Methacrylate ; therapeutic use ; Spinal Fusion ; methods ; Spinal Neoplasms ; surgery ; therapy ; Spinal Puncture ; Spine ; surgery ; Treatment Outcome

Percutaneous sacroplasty is a safe and effective procedure for sacral insufficient fractures under CT or fluoroscopic guidance; although, few reports exist about sacral metastatic tumors. We designed a pilot study to treat intractable pain caused by a sacral metastatic tumor with sacroplasty. A 62-year-old man and a 38-year-old woman with medically intractable pain due to metastatic tumors of S1 from lymphoma and lung cancer, respectively, underwent percutaneous sacroplasty. Over the course of the follow-up period, the two patients experienced substantial and immediate pain relief that persisted over a 3-month and beyond. The woman had deposition of PMMA (polymethyl methacrylate) in the needle track, but did not experience significant symptoms. No other peri-procedural complications were observed for either patient.
Adult ; Bone Cements/*therapeutic use ; Female ; *Fluoroscopy ; Humans ; Injections, Intralesional ; Male ; Middle Aged ; Pain, Intractable/etiology/*therapy ; Polymethyl Methacrylate/administration & dosage ; *Radiography, Interventional ; *Sacrum ; Spinal Neoplasms/complications/radiography/*secondary ; *Vertebroplasty/methods