Osteogenic inducer sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surface.

OBJECTIVE: Biomaterial can be locally applied to promote the osseointegration of dental implants. This study aimed to fabricate an osteogenic inducer (OI) sustained-release system and to evaluate its effects on the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces. METHODS: First of all, different contents of OI solution were added to the poly (lactic-co-glycolic acid) (PLGA) gel individually to investigate the best physical properties and drug-release rate. Moreover, osteoblasts were isolated from the calvaria of two-month-old New Zealand rabbits through sequential enzymatic digestion. Osteoblasts were seeded onto the surface of Ti disks (control group), Ti coated with PLGA gel (PLGA group), and Ti coated with the OI sustained-release system (PLGA+OI group). Cell adhesion was observed by scanning electron microscopy. Cell proliferation was analyzed by cell counting kit-8. Cell differentiation was tested by alizarin red staining, alkaline phosphatase (ALP) activity and osteogenic-related gene expression. RESULTS: The OI sustained-release system contained 15% OI solution had appropriate physical properties and drug-release rate. The osteoblasts in the PLGA+OI group were in a typical spindle shape with a considerable number indicating the promotion of adhesion and proliferation. The expression of early and late stage osteoblast differentiation genes in the PLGA+OI group were significantly higher than that of the control group and PLGA group at each time point. The PLGA group showed accelerated adhesion and differentiation but reduced proliferation compared with the control. CONCLUSION: The OI sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces. This system is a cost-effective osteoconductive biomaterial that might be promising for use in dental implantation.

Segmental Mirroring: Does It Eliminate the Need for Intraoperative Readjustment of the Virtually Pre-Bent Reconstruction Plates and Is It Economically Valuable?

PURPOSE: The aim of this study was to compare segmental mirroring with mirroring of the entire unaffected side to determine which method obviates intraoperative readjustment of virtually planned pre-bent plates and to evaluate the effect on costs. MATERIALS AND METHODS: Patients eligible for inclusion in this prospective study had unilateral mandibular discontinuity defects. Patients were randomly divided into 2 groups. In group I, models were constructed by mirroring the entire unaffected side of the mandible at the midsagittal plane. In group II, only the resected segments were cut and replaced by the corresponding mirrored healthy segments. The lesions were resected, and their sites were reconstructed using pre-bent reconstruction plates. The need for intraoperative plate readjustment, plate placement time, operation time, and operation costs were reviewed. RESULTS: Fifty patients were enrolled in this study. All but 5 plates in group I required readjustment. In group II, plates were placed without intraoperative handling. Average operating times were 4.20 ± 0.56 hours in group I and 3.186 ± 0.28 hours in group II (P = .00002). Mean times for plate placement were 33.36 ± 8.20 and 21.88 ± 5.73 minutes in groups I and II, respectively. The difference resulted in an average time gain of 11.48 minutes. Average personal costs per minute were US$740.77 for group I and US$560.87 for group II. The difference resulted in an average saving of approximately US$179.90. CONCLUSION: Segmental mirroring is superior in reflecting the bone anatomy in 3-dimensional models, thus eliminating intraoperative plate readjustment and providing better plate adaptation with better contour. It decreases operating time and costs and thus can be recommended for lesions that do not cross the midline.

Biomaterials for orbital fractures repair.

The unique and complex anatomy of the orbit requires significant contouring of the implants to restore the proper anatomy. Fractures of the orbital region have an incidence of 10-25% from the total facial fractures and the most common age group was the third decade of life. The majority of cases required reconstruction of the orbital floor to support the globe position and restore the shape of the orbit. The reason for this was that the bony walls were comminuted and/ or bone fragments were missing. Therefore, the reconstruction of the missing bone was important rather than reducing the bone fragments. This could be accomplished by using various materials. There is hardly any anatomic region in the human body that is so controversial in terms of appropriate material used for fracture repair: non resorbable versus resorbable, autogenous/ allogeneic/ xenogenous versus alloplastic material, non-prebent versus preformed (anatomical) plates, standard versus custom-made plates, nonporous versus porous material, non-coated versus coated plates. Thus, the importance of the material used for reconstruction becomes more challenging for the ophthalmologist and the oral and maxillofacial surgeon.

Comparison of the use of silastic with titanium prefabricated implant in type I thyroplasty.

INTRODUCTION: Type I thyroplasty is the treatment of choice for unilateral vocal cord palsy with no spontaneous recovery. OBJECTIVES: To compare the use of silastic implant with titanium vocal fold medializing implant (TVFMI®) in type I thyroplasty for unilateral vocal cord palsy with respect to subjective and objective improvement in voice, endoscopic changes in vocal cords, surgical time, and cost effectiveness. METHODOLOGY: This was a prospective study conducted on 40 patients with unilateral vocal cord paralysis who underwent type I thyroplasty with either silastic implant or TVFMI®. Pre-operative and four-week post-operative assessment and statistical comparison were performed by videolaryngoscopy, stroboscopy, perceptual assessment (GRBAS), subjective (voice handicap index) analysis of voice, and computer-assisted acoustic and electroglottographic assessment. The duration of surgery and cost of implant were also recorded. RESULTS: Although both implants showed improvement in quality of voice following thyroplasty, TVFMI® presents slightly better results in objective voice analysis. The surgery time for TVFMI®insertion was shorter, but the costs were higher. CONCLUSION: TVFMI® may be preferred for medialization thyroplasty as it presents better voice results and demands less surgical time; however, it is costlier than silastic implant.

Comparação do uso de implante de Silastic(r) com titânio pré-fabricado na tireoplastia tipo I / Comparison of the use of silastic with titanium prefabricated implant in type I thyroplasty

Introdução: A tireoplastia tipo I é o tratamento de escolha nas paralisias unilaterais das pregas Análise de custo-bene-vocais que não se recuperam espontaneamente. fício. Objetivos: Comparar o uso de implante de Silastic® com o uso de titânio pré-fabricado TVFMI® (Titanium Vocal Fold Medializing Implant) na tireoplastia tipo I para o tratamento da paralisia unilateral das pregas vocais com relação à melhora subjetiva e objetiva da voz, às alterações endoscópicas nas pregas vocais, ao tempo de cirurgia e à relação custo-benefício. Método: Trata-se de um estudo prospectivo com 40 pacientes portadores de paralisia unilateral das pregas vocais submetidos à tireoplastia tipo I com implante de silastic® ou TVFMI®. A avaliação e comparação estatística foram realizadas antes e quatro semanas depois da cirurgia por meio de videolaringoscopia, estroboscopia, análise perceptiva (escala GRBAS-Grade, Roughness, Breathiness, Asthenia, Strain) e subjetiva (IDV-índice de desvantagem vocal) da voz e avaliação eletroglotográfica e avaliação acústica computadorizada. Também foram observados o tempo de cirurgia e o custo do implante. Resultados: Embora os dois implantes mostrem melhora na qualidade da voz após a tireoplastia, o TVFMI® teve um resultado ligeiramente melhor na análise objetiva da voz. O TVFMI® levou menos tempo de cirurgia para ser inserido, porém foi mais caro. Conclusão: O TVFMI® poderá ser preferencial na tireoplastia de medialização, já que possui melhores resultados vocais e leva menos tempo de cirurgia, porém é mais caro que o implante de Silastic®. .

Introduction: Type I thyroplasty is the treatment of choice for unilateral vocal cord palsy with no spontaneous recovery. Objectives: To compare the use of silastic implant with titanium vocal fold medializing implant (TVFMI®) in type I thyroplasty for unilateral vocal cord palsy with respect to subjective and objective improvement in voice, endoscopic changes in vocal cords, surgical time, and cost effectiveness. Methodology: This was a prospective study conducted on 40 patients with unilateral vocal cord paralysis who underwent type I thyroplasty with either silastic implant or TVFMI®. Pre-operative and four-week post-operative assessment and statistical comparison were performed by videolaryngoscopy, stroboscopy, perceptual assessment (GRBAS), subjective (voice handicap index) analysis of voice, and computer-assisted acoustic and electroglottographic assessment. The duration of surgery and cost of implant were also recorded. Results: Although both implants showed improvement in quality of voice following thyroplasty, TVFMI® presents slightly better results in objective voice analysis. The surgery time for TVFMI®insertion was shorter, but the costs were higher. Conclusion: TVFMI® may be preferred for medialization thyroplasty as it presents better voice results and demands less surgical time; however, it is costlier than silastic implant. .

Valorization of titanium metal wastes as tanning agent used in leather industry.

The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77°C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning.

High-performance plastic dye-sensitized solar cells based on low-cost commercial P25 TiO2 and organic dye.

High-performance plastic dye-sensitized solar cells (DSCs) based on low-cost commercial Degussa P25 TiO(2) and organic indoline dye D149 have been fabricated using electrophoretic deposition (EPD) with compression post-treatment at room temperature. The pressed EPD electrode outperformed the sintered EPD electrode and as-prepared EPD electrode in short-circuit current density and power conversion efficiency. About 150% and 180% enhancement in power conversion efficiency have been achieved in DSC devices with sintering and compression post-treatment as compared to the as-prepared electrode, respectively. Several characterizations including intensity modulated photocurrent spectroscopy, incident photon-to-electron conversion efficiency and electrochemical impedance spectra have been employed to reveal the nature of improvement with post-treatment. Experimental results indicate that the sintering and compression post-treatment are beneficial to improve the electron transport and thus lead to the enhancement of photocurrent and power conversion efficiency. In addition, the compression post-treatment is more efficient than sintering post-treatment in improving interparticle connection in the as-prepared EPD electrode. Under optimized conditions, the conversion efficiency of plastic devices with D149-sensitized P25 TiO(2) photoanode has reached 5.76% under illumination of AM 1.5G (100 mW cm(-2)). This study demonstrates that the EPD combined with compression post-treatment provides a way to fabricate highly efficient plastic photovoltaic devices.

Appreciating the role of thermodynamics in LCA improvement analysis via an application to titanium dioxide nanoparticles.

Although many regard it as the most important step of life cycle assessment, improvement analysis is given relatively little attention in the literature. Most available improvement approaches are highly subjective, and traditional LCA methods often do not account for resources other than fossil fuels. In this work exergy is evaluated as a thermodynamically rigorous way of identifying process improvement opportunities. As a case study, a novel process for producing titanium dioxide nanoparticles is considered. A traditional impact assessment, a first law energy analysis, and an exergy analysis are done at both the process and life cycle scales. The results indicate that exergy analysis provides insights not available via other methods, especially for identifying unit operations with the greatest potential for improvement. Exergetic resource accounting at the life cycle scale shows that other materials are at least as significant as fossil fuels for the production of TiO2 nanoparticles in this process.

ISSLS prize winner: cost-effectiveness of two forms of circumferential lumbar fusion: a prospective randomized controlled trial.

STUDY DESIGN: Economic evaluation alongside a prospective, randomized controlled trial from a secondary care National Health Service (NHS) perspective. OBJECTIVE: To determine the cost-effectiveness of titanium cages (TC) compared with femoral ring allografts (FRA) in circumferential lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: A randomized controlled trial has shown the use of TC to be clinically inferior to the established practice of using FRA in circumferential lumbar fusion. Health economic evaluation is urgently needed to justify the continued use of TC, given that this treatment is less effective and, all things being equal, is assumed more costly than FRA. METHODS: Eighty-three patients were randomly allocated to receive either the TC or FRA as part of a circumferential lumbar fusion between 1998 and 2002. NHS costs related to the surgery and revision surgery needed during the trial period were monitored and adjusted to the base year (2005-2006 Pounds Sterling). The Short Form-6D (SF-6D) was administered before surgery and at 6, 12 and 24 months in order to elicit patient utility and subsequently Quality-Adjusted Life Years (QALYs) for the trial period. Return to paid employment was also monitored. Bootstrapped mean differences in discounted costs and benefits were generated in order to explore cost-effectiveness. RESULTS: A significant cost difference of pound 1950 (95% CI, pound 849 to pound 3145) in favor of FRA was found. Mean QALYs per patient over the 24-month trial period were 0.0522 (SD, 0.0326) in the TC group and 0.1914 (SD, 0.0398) in the FRA group, producing a significant difference of -0.1392 (95% CI, -0.2349 to -0.0436). With regard to employment, incremental productivity costs were estimated at pound 185,171 in favor of FRA. CONCLUSION: From an NHS perspective, the trial data show that TC is not cost-effective in circumferential lumbar fusion. The use of FRA was both cheaper and generated greater QALY gains. In addition, FRA patients reported a greater return to work rate.

Skeletal stability in bimaxillary orthognathic surgery: P(L/DL)LA-resorbable versus titanium osteofixation.

BACKGROUND: One-year skeletal stability following bimaxillary orthognathic surgery was assessed by comparing poly(L-lactide-co-DL-lactide) to titanium osteofixation. METHODS: Thirty patients underwent osteofixation with poly(L-lactide-co-DL-lactide) copolymer and 30 had 2.0-mm titanium-miniplate osteosyntheses. Lateral cephalograms were analyzed preoperatively, postoperatively, and at 1-year follow-up. Average +/- SD values were as follows in resorbable plate-osteosyntheses (number of cases/titanium controls): for maxillary advancement, 3.5 +/- 4.1 mm (n = 19)/5.4 +/- 3.5 mm (n = 21); setback, 2.8 +/- 3.7 mm (n = 9)/1.9 +/- 1.8 mm (n = 8); elongation, 4.2 +/- 3.6 mm (n = 18)/3.7 +/- 5.2 mm (n = 14); and intrusion, 1.9 +/- 1.7 mm (n = 12)/3.3 +/- 2.7 mm (n = 13); for mandibular advancement, 4.6 +/- 3.6 mm (n = 10)/6.3 +/- 8.8 mm (n = 18); setback, 7.5 +/- 8.3 mm (n = 20)/7.2 +/- 3.2 mm (n = 12); enlargement of the mandibular angle, 11.8 +/- 9.9 degrees (n = 19)/7.9 +/- 6.6 degrees (n = 21); and reduction, 4.5 +/- 3.2 degrees (n = 9)/6.3 +/- 6.6 degrees (n = 9). RESULTS: Preoperative to postoperative landmark positions within the study and control groups differed highly significantly (p = 0.008, paired t test), yet the amount of operative movement was comparable between the study and control groups (p = 0.5, two-sided t test). Absolute instability at the advanced A-point was (study group/controls) 2.3 +/- 1.8/2.4 +/- 2 mm, setback was 2.3 +/- 1.9 mm/2.5 +/- 1.7 mm, elongation at the anterior nasal spine was 3.8 +/- 3.1 mm/3.1 +/- 3.6 mm, intrusion was 2.1 +/- 1.9 mm/2.2 +/- 1.5 mm, advancement instability at the B-point was 4.9 +/- 4.3 mm/5.1 +/- 8.2 mm, setback was 3.0 +/- 2 mm/1.7 +/- 2 mm, mandibular angle enlargement instability was 6.7 +/- 8.9 degrees/8.2 +/- 9.6 degrees, and angle narrowing was 6.8 +/- 5.2 degrees/4.2 +/- 5.9 degrees. Absolute postoperative instability did not differ significantly between the study and control groups (p = 0.6). CONCLUSIONS: Resorbable osteofixation as tested proved to be as reliable as titanium, but as the study and control groups were not matched, the results have to be interpreted as preliminary. Resorbable materials permitted clinically faster occlusal and condylar settling than standard titanium osteosyntheses, as bone segments showed slight clinical mobility up to 6 weeks postoperatively.

[A comparative assessment of modern suture materials in stomach resection]. / Sravnitel'naia otsenka sovremennykh shovnykh materialov pri rezektsii zheludka.

Results of stomach resection by Bilrot-II in 30 experimental animals and 369 patients with gastric and duodenal ulcers were analyzed. Gastroenteroanastomoses were created with various sutures: capron, polysorb, titanium clips. Pneumopression, bacteriologic and morphologic examinations of anastomosis, fibroesophagogastroduodeno- and intestinoscopy, peripheral computed electrogastroenterography were used. It was revealed that mechanical suture with titanium clips was the best. Polysorb thread is inferior in tissue reaction to mechanical suture but superior to capron. Use of polysorb reduced rate of complications in immediate postoperative period 4 times. Taking into consideration high cost of suture devices it is reasonable to introduce polysorb in practice of abdominal surgery.

Titanium miniplates or stainless steel wire for cranial fixation: a prospective randomized comparison.

OBJECT: The authors designed a study to compare low-profile titanium miniplate fixation to that in which stainless steel wire is used. METHODS: Before undergoing craniotomy, 40 patients gave informed consent and were randomized to receive either wire or miniplate fixation. After dural closure, bone flap fixation was timed. The bone flap was measured for inward or outward offset and mobility to manual pressure on its margin. Three months postoperatively the bone flap margins were graded for appearance or palpation of an offset and for the presence of burr hole depressions. Twenty-four patients were randomized to receive miniplate fixation and 16 to receive stainless steel wire fixation. The time required for wire fixation was approximately 40% longer than that for miniplates (11.8 +/- 5.1 minutes compared with 8.3 +/- 5 minutes, p = 0.02). The offset of bone flaps after wire fixation was significantly greater than that with miniplates (1.6 +/- 1 mm compared with 0.3 +/- 0.6 mm, p < 0.001), as was the mobility of the bone flap on digital pressure (1.2 +/- 0.9 mm compared with 0.2 +/- 0.5 mm, p < 0.001). At the 3-month follow-up review, two of 12 patients had suboptimal results after wire fixation, whereas none of 14 patients had suboptimal results after miniplate fixation. When dichotomized for excellent or less-than-excellent postoperative results, the data were significantly better for patients who underwent miniplate fixation (p < 0.05). CONCLUSIONS: Titanium miniplate cranial fixation provides more accurate and rigid reapproximation of the bone edges, with results that are significantly better on close inspection or palpation. The additional cost of miniplate fixation may thus be justified in many cases.

Cranioplasty: don't forget the patient's own bone is cheaper than titanium.

Many calvarial bone defects are still being repaired using non-biological materials such as titanium when a patient's own bone can provide an alternative with all the immediate and long-term biological advantages (and resource benefits) that come with using autologous tissues.

Dentists' opinions on aspects of cast titanium restorations.

OBJECTIVES: The purpose of this paper was to study dentists' opinions regarding aspects of the clinical use of cast titanium restorations. METHODS: Since 1988 more than 10,000 cast titanium units of crowns and fixed partial dentures have been produced by the only dental laboratory that produces cast titanium restorations in Norway. A questionnaire on the clinical behaviour of such restorations was mailed to all 72 dental practitioners who were recorded in the computer file of this laboratory. RESULTS AND CONCLUSION: In the opinion of the 64 dental practitioners who completed the questionnaire, cast titanium is a useful supplement to conventional casting alloys, particularly because of its favourable cost. It has a satisfactory clinical behaviour, although there may be some problems related to technical and aesthetic aspects.

Dental students' understanding of titanium.

The understanding of titanium by students in the dental faculty of Tokyo Medical and Dental University was surveyed from 1990 to 1996. A seven-item questionnaire was used in the survey conducted during the first lecture of the dental materials and science course. The students' basic understanding of titanium was not very good and did not improve with time. However, their understanding improved significantly after the lecture and laboratory instructions.