Clinical applications of the T-Scan quantitative digital occlusal analysis technology: a systematic review.

STATEMENT OF THE PROBLEM: Occlusion is associated with all disciplines of dentistry and plays a major role in the longevity of both implant- and tooth-borne restorations. Achieving occlusal harmony ensures balance is established between the dental and myofascial structures, which can be measurably established to high numerical tolerances with the T-Scan digital occlusal analysis system. PURPOSE: To describe and evaluate the known and proven applications of T-Scan digital occlusal analysis in various dental practice disciplines through a systematic review of the literature. MATERIALS AND METHODS: An electronic, English-language PubMed/MEDLINE and Cochrane Central Registry of Controlled Trials database search using the keywords "T-Scan," "TMD," "Occlusion," "Implant Protected Occlusion," and "Orthodontics" was conducted without any date restrictions. The related journal findings were hand searched to determine studies that met the eligibility criteria for inclusion in the present systematic review. RESULTS: The PubMed/MEDLINE search identified 423 articles. After removing duplicates, the titles and abstracts of the remaining 421 studies were screened. 274 ineligible articles were excluded, leaving 147 articles. Of those, 33 articles were not in English, 27 full-text articles were not available, 4 were comments and letters to editors, 1 was a review, and 2 described techniques. A total of 86 articles met the eligibility criteria for inclusion. CONCLUSION: Much scientific evidence supports the use of T-Scan, as it measures relative occlusal contact forces and the time sequence durations of occlusal contacts objectively, accurately, and repeatedly for improved treatment outcomes. The system's hardware, sensor, and software evolution from T-Scan I to today's T-Scan 10 Novus system has overcome early sensor and system drawbacks to improve the clinical performance of T-Scan in many disciplines of dental medicine.

The effect of external magnetic field on osteogenic and antimicrobial behaviour of surface-functionalized custom titanium chamber with iron nanoparticles. A preliminary research.

PURPOSE: The controlled responsive characteristics of iron nanoparticles (FeNp) in magnetic fields make them an attractive prospect in this field. In the presence of a magnetic field, FeNp can significantly impact cell behaviour, leading to breakthroughs in nanotechnology. AIM/HYPOTHESIS: The aim is to determine the possible applications of iron nano particles (FeNp), and induced magnetic exposure role in osteoconduction and antibacterial activity. MATERIALS AND METHODS: The custom-grade IV titanium (Ti)hollow chamber is fabricated, surface treated with FeNp. Each titanium chamber contained neodymium, iron, and boron magnet disc, and the effect of FeNp on osteoblast-like cells (MG63) was evaluated in terms of cell attachment and survivability, morphological characteristics, particle absorption, and antibacterial properties. The effects of cellular uptake of FeNp and their responses to subcellular thrust were studied using fluorescent microscopy. MTT was used to determine cell viability, and von Kossa histochemical staining was used to determine matrix mineralization. RESULTS: In the magnetized Ti chambers group, osteogenic activity and mineralization were considerably greater than in the control groups (p 0.05). With a p value of 0.027, the S. aureus and E. coli were resistant to the antibacterial properties of the FeNp modified titanium custom Ti chamber (MIC: 0.03135 mg/mL and 0.02915 mg/mL, respectively). CONCLUSION: The one-of-a-kind, in vitro, conveniently modelled, limited sample study sheds light on the effect of surface-functionalized titanium custom Ti chamber with FeNp on MG63. The use of magnetized FeNp-surfaced implants for long-term strategic bone tissue engineering and bacteriostatic implants.

Complete-arch implant-supported fixed dental prostheses fabricated with PEEK and PEKK framework: a systematic review.

PURPOSE: To evaluate the performance of complete-arch implant-supported fixed dental prostheses (FDPs) fabricated with polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) framework in clinical cases. MATERIALS AND METHODS: This systematic review followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was registered in the International Prospective Register of Systematic Reviews with the number CRD42023399494. The electronic database PubMed, Cochrane Library and EBSCOhost were assessed for clinical research and reports on complete-arch implant-supported FDPs fabricated with PEEK and PEKK framework. Human studies with a minimum follow-up of 1 year and published in an English language were the only ones included. RESULTS: The initial database and hand search provided 564 articles. Finally, 12 articles published between 2018 and 2022 were included in this systematic review. The mean follow-up ranged from 1 year to 6 years. The included studies reported 119 (114 PEEK, 5 PEKK) complete-arch implant-supported FDPs during 1 year follow-up. The cumulative survival rate of prostheses with PEEK as a framework was 97.3%. Prostheses fractures and complications were found with both PEEK and PEKK frameworks. No implant failure reported with both PEEK and PEKK prostheses. CONCLUSION: In short-term follow-up, the complete-arch implant-supported FDPs with PEEK as a framework showed a good survival rate and acceptable health of the supporting tissues. The PEEK framework had shown adhesion issues as the most common prosthetic complication. Limited data were available on PEKK as framework material, so further long-term clinical trials are required.

Effect of Cissus quadrangularis Hydrogel on Enhancing Osseointegration of Titanium Implant to Bone: An In Vivo Study.

AIM: The aim of the study was to evaluate the osteogenic potential of Cissus quadrangularis (CQ) hydrogel in enhancing the osseointegration of titanium to the bone in an experimental rabbit model. MATERIALS AND METHODS: Six adult male New Zealand white rabbits were used in this study. A total of 24 implants (12 coated test implants and 12 uncoated control implants) were placed in these 6 rabbits. A polyethylene glycol (PEG) hydrogel was prepared with the C. quadrangularis hydrogel in which the test implants were coated. Each rabbit was operated on both hind legs and one implant, each, was placed in the femur and tibia. Hence, one rabbit received four implants [two test implants (HG coated) and two control implants (uncoated)]. The animals were sacrificed after 4 weeks, and the specimens were histomorphometrically analyzed. The bone-to-implant contact (BIC) and the bone area fraction occupancy (BAFO) were calculated using Image J analysis. RESULTS: The statistically analyzed values which were obtained by paired t-test, revealed that the average mean values were higher in the test implants (coated) than the control implants (uncoated). The BIC values of the test implants were not significantly different from the control implants in the case of both femur and tibia (p >0.05). The test implants showed significantly increased BAFO values in femur (p <0.05). However, the BAFO values of test implants in tibia did not vary significantly from the control implants. CONCLUSION: Based on the findings of the study, the authors conclude that the coating of C. quadrangularis hydrogel enhances the osseointegration of titanium implants to bone. The further studies need to be designed to check the osseointegrative potential of C. quadrangularis. CLINICAL SIGNIFICANCE: The findings of this study suggest that the C. quadrangularis hydrogel is a potent osteogenic material that can reduce the osseointegration period and thus enhance the patient compliance toward implant treatment.

Rehabilitation of Severe Atrophic Ridges with Zygomatic Implant and/or All-on-4 Treatment Concepts-A Case Series.

Rehabilitation of completely edentulous patients with implant-supported prosthesis (ISP) is the need of the day, but in many patients, the routine ISP is not possible due to the severe atrophic residual ridges. The present case series describes three cases with atrophic ridges rehabilitated using zygomatic implants and/or All-on-4 treatment concepts. In case 1 and case 3, in maxillary arch, there was not enough bone in Zone 3 to rehabilitate the patient with routine protocol followed for the All-on-4 treatment concept, so in these two cases, zygomatic implants were placed. Case 1 and case 2 were rehabilitated with Malo Bridge and case 3 with acrylic teeth-hybrid prosthesis using a computerized milling procedure to obtain improved fit, function, esthetics, and ease of retrievability whenever required.

Crestal Bone Changes and Patient Satisfaction with Single Implant-Retained Mandibular Overdentures with Dalla Bona and Locator Attachments with Immediate Loading Protocols. A Randomized Controlled Clinical Study.

PURPOSE: There is no enough evidence present on the success of single implant-retained mandibular overdentures (SIMO) with Dalla Bona and Locator attachments. This study aims to compare crestal bone loss and patient satisfaction with SIMO with Dalla Bona and Locator attachment following immediate loading protocols. MATERIAL AND METHODS: Twelve patients included in Group 1 received immediate SIMO with Dalla Bona attachments, and another twelve patients in Group 2 received immediate SIMO with Locator attachments in the mid symphyseal region. The follow-up was scheduled at 6 and 12 months after implant placement. The patient satisfaction with the denture was evaluated with the visual analog scale (VAS) score. The data obtained were statistically analyzed with the independent student t-test for intergroup comparison and repeated measures of ANOVA followed by Bonferroni's Post hoc analysis for intragroup comparison of mean crestal bone loss at a different time interval. RESULTS: Ten patients each in both the groups were available for follow-up. Crestal bone loss at 6 months follow-up for Dalla Bona group was 0.42 ± 0.10 mm on the mesial side and 0.43 ± 0.14 mm on the distal side and at 1 year 1.54 ± 0.16 mm on the mesial side and 1.66 ± 0.13 mm on the distal side. The mean crestal bone loss at 6 months follow-up for Locator group was 0.48 ± 0.16 mm on the mesial side and 0.45 ± 0.11 mm on the distal side and at 1 year was 1.71 ± 0.22 mm on mesial side and 1.74 ± 0.28 mm on the distal side. There was difference in bone loss at 6 months (mesial: 0.06 mm, p = 0.327; distal:0.02 mm; p = 0.726) and at 1 year (mesial: 0.17 mm, p = 0.063; distal: 0.08 mm; p = 0.423) in between two groups but the difference was statistically insignificant. There was a significant difference found in the VAS score for patient satisfaction with SIMO with Dalla Bona attachments and Locator attachments at 6 months (54.2 vs. 51.8, p = 0.005) and 1 year (60.6 vs. 55.2, p = 0.005). CONCLUSIONS: Patient satisfaction with SIMO with Dalla Bona attachments was higher during the follow-up. SIMO with Dalla Bona attachments had less crestal bone loss and less prosthetic complications when compared to Locator attachments, although the difference in the bone loss was statistically insignificant.

Bone Marrow Mesenchymal Stromal Cells (BMMSCs) Augment Osteointegration of Dental Implants in Type 1 Diabetic Rabbits: An X-Ray Micro-Computed Tomographic Evaluation.

Background and objectives: The study aimed to investigate the effect of bone marrow mesenchymal stromal cells (BMMSCs) on implant-bone osseointegration in type I diabetic New Zealand rabbits. Materials and methods: BMMSCs harvested from healthy rabbits were processed and validated for purity and osteocyte differentiability. Mandibular incisors of diabetic and control rabbits were carefully extracted, and the sockets were plugged with collagen sponges. Platelet-rich plasma (PRP) containing osteoinductive BMMSCs, and plain PRP were injected into the collagen sponge of the right and left sockets respectively. Dental implants of 2.6 mm diameter and 10 mm length were inserted into the collagen sponge of both sockets. All the animals were sacrificed six weeks post surgery to evaluate an early stage of osseointegration; the mandibles scanned by X-ray microcomputed tomography (µCT) and subjected to 3D analysis. The µCT parameters of the right implant were paired against that of the left side of each animal and analyzed by paired T-test. Results: The preclinical evaluation of the viability and osteocyte differentiation of the BMMSCs were consistent between both the donor samples. The osseointegration of dental implants with stem cell therapy (BMMSCs + PRP + collagen) in normal and diabetic rabbits was significantly higher than that of implants with adjunctive PRP + collagen only (p < 0.05). Conclusion: Stem Cell therapy with osteoinductive BMMSCs and PRP can offer a novel approach to enhance the osseointegration of dental implants in uncontrolled diabetic patients.

Effect of nanoparticles on color stability and mechanical and biological properties of maxillofacial silicone elastomer: A systematic review.

AIM: The aim of this systematic review was to evaluate the effect of addition of various nanoparticles into maxillofacial silicone elastomer on color stability and mechanical and biological properties of the silicone elastomer. SETTINGS AND DESIGN: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines(PRISMA). MATERIALS AND METHODS: The electronic database search in MEDLINE/PubMed was based on population (silicone elastomer), intervention (nanoparticles), comparison (unreinforced silicone elastomer with nanoparticle-reinforced silicone elastomer), outcome (color stability and mechanical, physical, and biological properties), i.e., PICO framework. The key words used are ("maxillofacial silicone" OR "silicone elastomer" OR "facial silicone") AND ("nanoparticles" OR "Nano-oxides") AND ("colour stability" OR "Hardness," "tensile strength" OR "tear strength" OR "antifungal activity"). RESULTS: The database search resulted in 2099 studies, of which 2066 articles were excluded as they were irrelevant, duplicates, and data were not available. The remaining 33 full-text articles were assessed for eligibility, out of which 2 articles were in Chinese language, 3 articles were thesis documents, and 8 were review articles. A total of 12 articles were excluded and the remaining 20 articles were included. One article was yielded by hand search of references of included studies. A total of 21 studies were included in the present systematic review. CONCLUSION: With the available evidence in the literature, it can be concluded that addition of nanoparticles at various concentrations may improve the physical and mechanical properties and color stability of the prosthesis made from the silicone elastomers.

Attitude of dental professionals toward cast partial denture: A questionnaire survey in India.

AIMS: The use of cast partial dentures (CPDs) has been decreased and its importance has been declined in the teaching curriculum. The purpose of this survey was to evaluate the attitudes of dental professionals toward conditions using CPDs in private practice in India. SETTINGS AND DESIGN: Descriptive survey. MATERIALS AND METHODS: This survey consists of eight close-ended questions concerning the use of CPD by dental professionals practicing in India. The URLs of the questionnaire were shared via E-mail to dentists practicing throughout India, to obtain a response of 384 which is a predetermined sample size. STATISTICAL ANALYSIS USED: Statistical analysis was done using counts and percentages and the results were further analyzed statistically by the Chi-square test. RESULTS: Nearly 42.79% of general dental practitioners (GDPs), 47.26% of prosthodontists, and 9.95% of other specialist dentists responded to the questionnaire. GDPs mostly preferred removable partial dentures (RPDs) (71.87%) and fixed partial dentures (57.22%), whereas prosthodontists preferred mostly implant (60.91%). GDPs mostly preferred flexible dentures (62.42%), whereas prosthodontists preferred CPDs 62.84%. Almost 52.50% of the GDPs mostly raised a cost issue and 63.11% of the prosthodontists had difficulty in adjustment with CPDs. Nearly 63.46% of the dentists told that implant-supported restorations are better options compared to CPDs; still, majority of the dentists (53.23%) were in favor that more importance for teaching CPDs in graduation curriculum should be given. CONCLUSIONS: This survey shows that in India a significant proportion of GDPs (71.87%) preferred RPDs, mostly flexible dentures (62.42%) due to their low cost compared to CPDs. Prosthodontists mostly preferred implants (60.91%) because they are more confident and better trained in these. It is recommended that more importance be given in teaching implants along with CPDs in graduation curriculum so that practitioners can better educate their patients about implants and their advantages over flexible dentures and their utilization in cases where patients are not willing for CPDs.

An iris positioning device and centering approach: A technique.

For patients who have lost an eye as result of trauma or a carcinoma, accurate replacement with an ocular prosthesis that is symmetrical to the natural eye is essential. This report describes a technique for recording the measurement and position of the iris of the natural eye and accurately transferring it to the prosthetic eye of the patient. The technique is both straightforward and accurate.

Osseoperception in Dental Implants: A Systematic Review.

PURPOSE: Replacement of lost teeth has significant functional and psychosocial effects. The capability of osseointegrated dental implants to transmit a certain amount of sensibility is still unclear. The phenomenon of developing a certain amount of tactile sensibility through osseointegrated dental implants is called osseoperception. The aim of this article is to evaluate the available literature to find osseoperception associated with dental implants. MATERIALS AND METHODS: To identify suitable literature, an electronic search was performed using Medline and PubMed database. Articles published in English and articles whose abstract is available in English were included. The articles included in the review were based on osseoperception, tactile sensation, and neurophysiological mechanoreceptors in relation to dental implants. Articles on peri-implantitis and infection-related sensitivity were not included. Review articles without the original data were excluded, although references to potentially pertinent articles were noted for further follow-up. The phenomenon of osseoperception remains a matter of debate, so the search strategy mainly focused on articles on osseoperception and tactile sensibility of dental implants. This review presents the histological, neurophysiological, and psychophysical evidence of osseoperception and also the role of mechanoreceptors in osseoperception. RESULTS: The literature on osseoperception in dental implants is very scarce. The initial literature search resulted in 90 articles, of which 81 articles that fulfilled the inclusion criteria were included in this systematic review. CONCLUSION: Patients restored with implant-supported prostheses reported improved tactile and motor function when compared with patients wearing complete dentures.

Hidden Overdenture Bar in Fixed Implant-retained Hybrid Prosthesis: Report of a Novel Technique.

INTRODUCTION: Every patient needs a comprehensive treatment planning. Dentists must consider the advantages and disadvantages of the available implant prosthetic options and match them to patient's expectations. Hybrid denture prosthesis is one, i.e., fabricated and retained by screw threaded into implant abutments, most of the time on four implants. Sometimes due to failure of an implant, the prosthesis needs to be replaced with a newer casting to accommodate the existing implants. Clinical consideration: This article presents a novel technique, wherein the existing framework of the fixed prosthesis can be used to convert the fixed prosthesis to removable prosthesis on the existing implants, without recasting. CLINICAL SIGNIFICANCE: The implant is economical and easily convertible from a fixed-fixed to a fixed-removable prosthesis. Hence, there is reduced morbidity, reduced cost, and an increased psychological comfort for the patient.

Comparison of masticatory efficiency, patient satisfaction for single, two, and three implants supported overdenture in the same patient: A pilot study.

STATEMENT OF PROBLEM: Over 30% of the world population suffers from edentulism. Implant supported overdenture have been a relatively successful treatment option for edentulism and have shown to slowed the rate of residual resorption and maintain the vertical height of the residual. PURPOSE: The purpose of this study was to measure patient masticatary efficiency and satisfaction with the mandibular one-, two-, and three-implant-retained overdenture therapy when compared with conventional denture in a the same patients. MATERIALS AND METHODS: Ten complete edentulous patients, who were wearing conventional complete dentures, were involved in this study. Three single piece endosseous implant of 3.0 mm in diameter and 13 mm in length were surgically placed in the mandible in the region of B, C, and D. Mandibular denture was connected for single, two, and three implant supported overdenture periodically and checked for masticatory efficiency using a bite gauge and patient satisfaction using a questionnaire. RESULTS: Statistical analysis was done using Wilcoxon signed rank test. Four groups of bite forces when compared to each other. Group 1 was compared with Group 2, with the statistical value showing significance. Signed rank test showed no significance (0.268) when Group 2 was compared with Group 3. When Group 3 was compared with Group 4, and Group 1 compared with Group 4, rank test showed significant values. Four groups were compared with each other for patient satisfaction, Group 1 was compared with Group 2, with the statistical value showing no significance. CONCLUSIONS: A single midline implant supported overdenture can be considered as a suitable and cost-effective treatment option over conventional denture. The study concludes that masticatory efficiency of this single midline implant supported overdenture is better than the conventional complete denture.

Magnet retained lip prosthesis in a geriatric patient.

Surgical resection of lips is a relatively rare procedure. A defective lip may cause the patient to feel socially vulnerable as well as functionally handicapped and the defect will influence the patient's self-esteem and body image. Patients with labial defects also experience speech problems along with drying and crusting of the tissues in the area of defect. The lip and cheek provide a valve mechanism for speech. Rehabilitation of patients with this type of surgery creates numerous challenges for both the surgical and the maxillofacial prosthetic teams. The goals of prosthetic treatment include regaining favorable speech and restoration of esthetics. This case report presents a 65-year-old woman who was referred for restoration of her lost lip. This case paper describes a quick and simple method of positioning magnets with lip prosthesis attached to maxillary denture and thus esthetics and speech of the patient is restored. Use of retention magnets simplify the clinical and laboratory phase retains the denture and makes it stable and comfortable for the patient. The advent of magnets has enhanced the dental practitioner's capabilities with a remarkably improved potential for increasing prosthesis stability and preserving tissue.

Osseointegrated dental implants in growing children: a literature review.

Edentulism is usually associated with the aging patient. However, total or partial tooth loss also affects young individuals, mainly as a result of trauma, decay, anodontia, or congenital and acquired jaw defects involving the alveolar processes. For elderly patients, the use of oral implants has become an accepted treatment modality for edentulism, and most of today's knowledge regarding implants is based on such practice. There has been hesitation to perform implant therapy for growing children; hence, few children to date have been provided with implant-supported construction. Consequently, little is known about the outcome of the osseointegration procedure in young patients, and until now, only a limited number of case presentations have been reported. This article reviews the current literature to discuss the use of dental implants in growing patients and the influence of maxillary and mandibular skeletal and dental growth on the stability of those implants. The literature review was performed through Science Direct, Wileys Blackwell Synergy, PubMed, Google, Embase, Medknow publications, and Springer for references published from 1963 to 2011. It is recommended to wait for the completion of dental and skeletal growth, except for severe cases of ectodermal dysplasia.

Heat generated by dental implant drills during osteotomy-a review: heat generated by dental implant drills.

STATEMENT OF PROBLEM: Osseointegration is the more stable situation and results in a high success rate of dental implants. Heat generation during rotary cutting is one of the important factors influencing the development of osseointegration. PURPOSE: To assess the various factors related to implant drills responsible for heat generation during osteotomy. MATERIALS AND METHODS: To identify suitable literature, an electronic search was performed using Medline and Pubmed database. Articles published in between 1960 to February 2013 were searched. The search is focused on heat generated by dental implant drills during osteotomy. Various factors related to implant drill such effect of number of blades; drill design, drill fatigue, drill speed and force applied during osteotomies which were responsible for heat generation were reviewed. Titles and abstracts were screened, and literature that fulfilled the inclusion criteria was selected for a full-text reading. RESULTS: The initial literature search resulted in 299 articles out of which only 70 articles fulfils the inclusion criteria and were included in this systematic review. Many factors related to implant drill responsible for heat generation were found. Successful preparation of an implant cavity with minimal damage to the surrounding bone depends on the avoidance of excessive temperature generation during surgical drilling. CONCLUSION: The relationship between heat generated and implant drilling osteotomy is multifactorial in nature and its complexity has not been fully studied. Lack of scientific knowledge regarding this issue still exists. Further studies should be conducted to determine the various factors which generate less heat while osteotomy such as ideal ratio of force and speed in vivo, exact time to replace a drill, ideal drill design, irrigation system, drill-bone contact area.

Enhancing bone tissue engineering using iron nanoparticles and magnetic fields: A focus on cytomechanics and angiogenesis in the chicken egg chorioallantoic membrane model.

AIM: To evaluate the potential of iron nanoparticles (FeNPs) in conjunction with magnetic fields (MFs) to enhance osteoblast cytomechanics, promote cell homing, bone development activity, and antibacterial capabilities, and to assess their in vivo angiogenic viability using the chicken egg chorioallantoic membrane (CAM) model. SETTINGS AND DESIGN: Experimental study conducted in a laboratory setting to investigate the effects of FeNPs and MFs on osteoblast cells and angiogenesis using a custom titanium (Ti) substrate coated with FeNPs. MATERIALS AND METHODS: A custom titanium (Ti) was coated with FeNPs. Evaluations were conducted to analyze the antibacterial properties, cell adhesion, durability, physical characteristics, and nanoparticle absorption associated with FeNPs. Cell physical characteristics were assessed using protein markers, and microscopy, CAM model, was used to quantify blood vessel formation and morphology to assess the FeNP-coated Ti's angiogenic potential. This in vivo study provided critical insights into tissue response and regenerative properties for biomedical applications. STATISTICAL ANALYSIS: Statistical analysis was performed using appropriate tests to compare experimental groups and controls. Significance was determined at P < 0.05. RESULTS: FeNPs and MFs notably improved osteoblast cell mechanical properties facilitated the growth and formation of new blood vessels and bone tissue and promoted cell migration to targeted sites. In the group treated with FeNPs and exposed to MFs, there was a significant increase in vessel percentage area (76.03%) compared to control groups (58.11%), along with enhanced mineralization and robust antibacterial effects (P < 0.05). CONCLUSION: The study highlights the promising potential of FeNPs in fostering the growth of new blood vessels, promoting the formation of bone tissue, and facilitating targeted cell migration. These findings underscore the importance of further investigating the mechanical traits of FeNPs, as they could significantly advance the development of effective bone tissue engineering techniques, ultimately enhancing clinical outcomes in the field.

Biomechanical evaluation of macro and micro designed screw-type implants: an insertion torque and removal torque study in rabbits.

OBJECTIVE: To investigate the combined effect of macro and pitch shortened threads on primary and secondary stability during healing, but before dynamic loading. MATERIALS AND METHODS: Two sets of turned implants with different macro geometry were prepared. The test group possessed pitch shortened threads in between the large threads and the control group did not have thread alterations. The two implant groups were placed in both femur and tibiae of 10 lop-eared rabbits, and at the time of implant insertion, insertion torques were recorded. After 4 weeks, all implants were subjected to removal torque tests. RESULTS: The insertion torque values for the control and test groups for the tibia were 15.7 and 20.6 Ncm, respectively, and for the femur, 11.8, and 12.8 Ncm respectively. The removal torque values for the control and test groups in the tibia were 7.9 and 9.1 Ncm, respectively, and for the femur, 7.9 and 7.7 Ncm respectively. There was no statistically significant difference between the control and test groups. CONCLUSION: Under limited dynamic load, the addition of pitch shortened threads did not significantly improve either the primary or the secondary stability of the implants in bone.

Evaluation of stress pattern generated through various thread designs of dental implants loaded in a condition of immediately after placement and on osseointegration--an FEA study.

PURPOSE: To determine the stress pattern generated through various thread design in experimental simulation models, when loaded immediately after placement and after osseointegration. METHODS: Three-dimensional (3D) models were designed using CATIA, computer-aided design modeling software. The study was planned in 2 stages. Eight 2D models were constructed of different thread forms, one set with frictionless and other with bonded for bone to implant interface and loaded vertically with 100 N. In Stage II, 6 3D models of the different threads embedded in the cortical bone were constructed and loaded vertically and obliquely. RESULTS: In 2D models, the von Mises stress concentrated at the crest in the bonded connection thread designs. The stress levels were in the range of 7 to 13 MPa. In the frictional implant bone interface, the thread designs had a clear effect on the stress levels in the bone. In the 3D analysis, the complete implant design affected the stress levels. CONCLUSIONS: The thread design affects the magnitude of the stress peak in the bone more effectively in immediately loaded (frictionless) implants than the osseointegrated (bonded) implants. Maximum stress was observed at the first thread in most of the osseointegrated implants.

A fixed guide flange appliance for patients after a hemimandibulectomy.

Oral carcinoma destroys structures, including the maxilla and mandible, which often require surgical management and rehabilitation. Poor tissue support after mandibular reconstruction in patients with hemimandibular defects hinders the reconstruction of functional and stable mandibular guide flange prostheses. The fabrication and use of a fixed guide flange prosthesis for rehabilitating patients with hemimandibular defects is described. The device permitted the use of the same prosthesis for both the functional and mechanical correction of mandibular deviation and is indicated where the fabrication of other appliances is contraindicated because of the compromised oral and physical state of the patient.