Displaying publications 1 - 20 of 33 in total

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  1. Sadollah A, Bahreininejad A
    J Mech Behav Biomed Mater, 2011 Oct;4(7):1384-95.
    PMID: 21783149 DOI: 10.1016/j.jmbbm.2011.05.009
    Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature.
    Matched MeSH terms: Dental Prosthesis Design/methods*
  2. Hassan LA, Goo CL
    Dent Mater J, 2021 Sep 30;40(5):1189-1195.
    PMID: 34078778 DOI: 10.4012/dmj.2020-408
    This research aimed to evaluate the effect of cement space on the marginal discrepancy and retention of computer-aided design/computer-aided manufacturing (CAD/CAM) crowns. A total of 30 premolar Frasaco teeth were machined to receive crowns with cement spaces of 70, 90, and 110 μm. The marginal discrepancy measurements were done before and after cementation. Pull-off test was conducted using universal testing machine (UTM). Data was analyzed using two-way mixed ANOVA with post-hoc Bonferroni test and Kruskal-Wallis test. The crowns with cement space of 70 μm showed a significantly higher absolute marginal discrepancy than those with 90 and 110 μm. No significant effect on the crown retention was found. Within the limitations of this study, modifying cement space to 90 μm and 110 μm may improve the marginal adaptation of CAD/CAM crown, whereas adjusting cement space from 70 to 110 μm did not significantly affect the crown retention.
    Matched MeSH terms: Dental Prosthesis Design*
  3. Haider KG, Lewis GR
    Quintessence Int, 1994 Jan;25(1):23-6.
    PMID: 8190877
    A variety of problems faces the prosthodontist attempting reconstruction of maxillary defects. There are various treatment options for patients requiring a partial maxillectomy and an obturator prosthesis. Reduced adaptability makes it difficult for the patient to learn to use a new appliance, unless existing skills can be employed. It is therefore helpful to reproduce familiar features of a patient's existing obturator, especially if this has been used successfully over a transition period.
    Matched MeSH terms: Dental Prosthesis Design/methods*
  4. Omar H, Atta O, El-Mowafy O, Khan SA
    J Dent, 2010;38 Suppl 2:e95-9.
    PMID: 20493232 DOI: 10.1016/j.jdent.2010.05.006
    To determine the effect of thickness of porcelain veneers constructed from CAD-CAM on their final color when two resin cements were used.
    Matched MeSH terms: Dental Prosthesis Design/instrumentation*; Dental Prosthesis Design/methods
  5. Kassim ZH, Nor Hisham ND, Dardiri NA, Goot Heah K, Hazwani Baharuddin I, De Angelis N
    Minerva Stomatol, 2019 Dec;68(6):291-296.
    PMID: 32052617 DOI: 10.23736/S0026-4970.19.04242-0
    BACKGROUND: The aims of this study were to enumerate the primary implant stability quotient (ISQ) value of self-tapping dual etched implants and to explore the influence of parameters such as implant length, implant diameter, age, gender, implant location and osteotomy preparation on the ISQ value.

    METHODS: Retrospective data from clinical worksheets given to participants during two implant courses held between the periods of 2013 to 2014 were evaluated. A total of 61 implants were considered based on the inclusion criteria. The effects of parameters such as implant diameter, implant length, age, gender, implant location and osteotomy protocol on ISQ values were analyzed.

    RESULTS: Mean ISQ value for all implants was 67.21±9.13. Age of patients (P=0.016) and location of implants (P=0.041) had a significant linear relationship with the ISQ values. Within the age limit of the patients in this study, it was found that an increase in one year of patient's age results in 0.20 decrease in ISQ value (95% CI: -0.36, -0.04). However, placing an implant in the posterior maxilla may negatively affect the ISQ with a likely decrease in primary stability by 6.76 ISQ value (95% CI: -13.22, -0.30).

    CONCLUSIONS: The results suggest that the mean ISQ achieved by the participants were comparable with the range reported for this particular type of implants. The patient's age and location of implants were elucidated as the determinant factors of primary implant stability.

    Matched MeSH terms: Dental Prosthesis Design
  6. Farook TH, Barman A, Abdullah JY, Jamayet NB
    J Prosthodont, 2021 Jun;30(5):420-429.
    PMID: 33200429 DOI: 10.1111/jopr.13286
    PURPOSE: Mesh optimization reduces the texture quality of 3D models in order to reduce storage file size and computational load on a personal computer. This study aims to explore mesh optimization using open source (free) software in the context of prosthodontic application.

    MATERIALS AND METHODS: An auricular prosthesis, a complete denture, and anterior and posterior crowns were constructed using conventional methods and laser scanned to create computerized 3D meshes. The meshes were optimized independently by four computer-aided design software (Meshmixer, Meshlab, Blender, and SculptGL) to 100%, 90%, 75%, 50%, and 25% levels of original file size. Upon optimization, the following parameters were virtually evaluated and compared; mesh vertices, file size, mesh surface area (SA), mesh volume (V), interpoint discrepancies (geometric similarity based on virtual point overlapping), and spatial similarity (volumetric similarity based on shape overlapping). The influence of software and optimization on surface area and volume of each prosthesis was evaluated independently using multiple linear regression.

    RESULTS: There were clear observable differences in vertices, file size, surface area, and volume. The choice of software significantly influenced the overall virtual parameters of auricular prosthesis [SA: F(4,15) = 12.93, R2 = 0.67, p < 0.001. V: F(4,15) = 9.33, R2 = 0.64, p < 0.001] and complete denture [SA: F(4,15) = 10.81, R2 = 0.67, p < 0.001. V: F(4,15) = 3.50, R2 = 0.34, p = 0.030] across optimization levels. Interpoint discrepancies were however limited to <0.1mm and volumetric similarity was >97%.

    CONCLUSION: Open-source mesh optimization of smaller dental prostheses in this study produced minimal loss of geometric and volumetric details. SculptGL models were most influenced by the amount of optimization performed.

    Matched MeSH terms: Dental Prosthesis Design
  7. Tarib NA, Seong TW, Chuen KM, Kun MS, Ahmad M, Kamarudin KH
    Eur J Prosthodont Restor Dent, 2012 Mar;20(1):35-9.
    PMID: 22474935
    This paper aims to evaluate the effect of splinting during implant impression. A master model with two fixtures at the sites of 45 and 47 was used. 20 impressions were made for all four techniques: (A) indirect; (B) direct, unsplinted; (C) direct, splinted; and (D) direct, splinted, sectioned, and re-splinted. Splinting was undertaken with autopolymerizing acrylic resin (AAR). Horizontal distance between fixtures was compared using a digital caliper. The difference in distance were analysed with one-way ANOVA. Group A showed a significantly lowest accuracy among all techniques (p < or = 0.05). There was no significant difference of accuracy among the groups using direct techniques (p > or = 0.05). Group D was more accurate compared to group B and C. We conclude that splinting of impression copings would be beneficial to obtain an accurate impression.
    Matched MeSH terms: Dental Prosthesis Design*
  8. Sockalingam S
    J Indian Soc Pedod Prev Dent, 2011 Jan-Mar;29(1):53-6.
    PMID: 21521920 DOI: 10.4103/0970-4388.79938
    Amelogenesis imperfecta represents a group of dental developmental conditions that are genomic in origin. Hypoplastic AI, hypomineralised AI or both in combination were the most common types seen clinically. This paper describes oral rehabilitation of a 9-year-old Malay girl with inherited hypoplastic AI using transparent thermoforming templates. The defective surface areas were reconstructed to their original dimensions on stone cast models of the upper and lower arches using composite, and transparent thermoform templates were fabricated on the models. The templates were used as crown formers to reconstruct the defective teeth clinically using esthetically matching composite. The usage of the templates allowed direct light curing of the composite, accurate reproducibility of the anatomic contours of the defective teeth, reduced chair-side time and easy contouring and placement of homogenous thickness of composite in otherwise inaccessible sites of the affected teeth.
    Matched MeSH terms: Dental Prosthesis Design*
  9. Baig MR, Tan KB, Nicholls JI
    J Prosthet Dent, 2010 Oct;104(4):216-27.
    PMID: 20875526 DOI: 10.1016/S0022-3913(10)60128-X
    The marginal fit of crowns is a concern for clinicians, and there is no conclusive evidence of any one margin configuration yielding better results than others in terms of marginal fit.
    Matched MeSH terms: Dental Prosthesis Design*
  10. Shankargouda SB, Sidhu P, Kardalkar S, Desai PM
    J Prosthodont, 2017 Feb;26(2):168-171.
    PMID: 26479878 DOI: 10.1111/jopr.12385
    Residual ridge resorption is a rapid, progressive, irreversible, and inevitable process of bone resorption. Long-standing teeth and implants have been shown to have maintained the bone around them without resorption. Thus, overdenture therapy has been proven to be beneficial in situations where few remaining teeth are present. In addition to the various advantages seen with tooth-supported telescopic overdentures, a few shortcomings can also be expected, including unseating of the overdenture, increased bulk of the prosthesis, secondary caries, etc. The precise transfer of the secondary telescopic copings to maintain the spatial relationship, without any micromovement, remains the most critical step in ensuring the success of the tooth-supported telescopic prosthesis. Thus, a simple and innovative technique of splinting the secondary copings was devised to prevent distortion and micromovement and maintain its spatial relationship.
    Matched MeSH terms: Dental Prosthesis Design*
  11. Baig MR, Buzayan MM, Yunus N
    J Investig Clin Dent, 2018 May;9(2):e12320.
    PMID: 29349910 DOI: 10.1111/jicd.12320
    AIM: The aim of the present study was to assess the accuracy of multi-unit dental implant casts obtained from two elastomeric impression materials, vinyl polyether silicone (VPES) and polyether (PE), and to test the effect of splinting of impression copings on the accuracy of implant casts.

    METHODS: Forty direct impressions of a mandibular reference model fitted with six dental implants and multibase abutments were made using VPES and PE, and implant casts were poured (N = 20). The VPES and PE groups were split into four subgroups of five each, based on splinting type: (a) no splinting; (b) bite registration polyether; (c) bite registration addition silicone; and (d) autopolymerizing acrylic resin. The accuracy of implant-abutment replica positions was calculated on the experimental casts, in terms of interimplant distances in the x, y, and z-axes, using a coordinate measuring machine; values were compared with those measured on the reference model. Data were analyzed using non-parametrical Kruskal-Wallis and Mann-Whitney tests at α = .05.

    RESULTS: The differences between the two impression materials, VPES and PE, regardless of splinting type, were not statistically significant (P>.05). Non-splinting and splinting groups were also not significantly different for both PE and VPES (P>.05).

    CONCLUSIONS: The accuracy of VPES impression material seemed comparable with PE for multi-implant abutment-level impressions. Splinting had no effect on the accuracy of implant impressions.

    Matched MeSH terms: Dental Prosthesis Design*
  12. Mehrali M, Shirazi FS, Mehrali M, Metselaar HS, Kadri NA, Osman NA
    J Biomed Mater Res A, 2013 Oct;101(10):3046-57.
    PMID: 23754641 DOI: 10.1002/jbm.a.34588
    Functionally graded material (FGM) is a heterogeneous composite material including a number of constituents that exhibit a compositional gradient from one surface of the material to the other subsequently, resulting in a material with continuously varying properties in the thickness direction. FGMs are gaining attention for biomedical applications, especially for implants, owing to their reported superior composition. Dental implants can be functionally graded to create an optimized mechanical behavior and achieve the intended biocompatibility and osseointegration improvement. This review presents a comprehensive summary of biomaterials and manufacturing techniques researchers employ throughout the world. Generally, FGM and FGM porous biomaterials are more difficult to fabricate than uniform or homogenous biomaterials. Therefore, our discussion is intended to give the readers about successful and obstacles fabrication of FGM and porous FGM in dental implants that will bring state-of-the-art technology to the bedside and develop quality of life and present standards of care.
    Matched MeSH terms: Dental Prosthesis Design
  13. Rahman SA, Muhammad H, Haque S, Alam MK
    J Contemp Dent Pract, 2019 Feb 01;20(2):173-178.
    PMID: 31058631
    AIM: The aim of this study was to evaluate the changes in the peri-implant hard and soft tissues and implant stability and to assess the correlation of bone loss and peri-implant probing depth with implant stability.

    MATERIALS AND METHODS: Twenty-one patients with implants were included in this study and implants were assessed by resonance frequency analysis (RFA). Bone levels of the implants were assessed by measuring mesial and distal bone levels from the periapical radiograph, and soft tissue was assessed from probing depth using a periodontal probe. Implants were assessed for stability and probing depth at pre-loading, at 3 months and 6 months post-loading. RFA and probing depth were statistically compared from different time points. Correlation of probing depth and marginal bone loss with implant stability was also determined.

    RESULTS: The average change in implant stability quotient (ISQ) measurements from pre-loading to 6 months post-loading was found to be statistically significant (p <0.005). The average probing depth reduced from 1.767 mm at pre-loading to 1.671 mm at post-loading 3 months, and 1.600 mm at post-loading 6 months. At 6 months of function, radiographic examination yielded 0.786 mm mesial bone loss and 0.8 mm distal bone loss. It was found to be statistically significant (p <0.005) but within an acceptable range. No significant correlation was found between implant stability and bone loss; and implant stability and probing depth.

    CONCLUSION: The study revealed an increasing trend in implant stability values with the time that indicates successful osseointegration. Increasing mean values for mesial and distal bone loss were also found.

    CLINICAL SIGNIFICANCE: The success of dental implants is highly dependent on the quality of bone and implant-bone interface, i.e., osseointegration. The most important factors that influence the survival rate of an implant is initial stability. The present study found the changes in the peri-implant hard and soft tissues and implant stability. This article, while being a prospective study, may show the evidence of successful osseointegration by increasing trend in implant stability (RFA) values with time which can help to the clinician in the long-term management of implants.

    Matched MeSH terms: Dental Prosthesis Design
  14. Ishak MI, Kadir MR, Sulaiman E, Kasim NH
    Int J Oral Maxillofac Implants, 2013 May-Jun;28(3):e151-60.
    PMID: 23748334 DOI: 10.11607/jomi.2304
    To compare the extramaxillary approach with the widely used intrasinus approach via finite element method.
    Matched MeSH terms: Dental Prosthesis Design/methods*
  15. Saidin S, Abdul Kadir MR, Sulaiman E, Abu Kasim NH
    J Dent, 2012 Jun;40(6):467-74.
    PMID: 22366313 DOI: 10.1016/j.jdent.2012.02.009
    The aim of this study was to analyse micromotion and stress distribution at the connections of implants and four types of abutments: internal hexagonal, internal octagonal, internal conical and trilobe.
    Matched MeSH terms: Dental Prosthesis Design*
  16. Ishak MI, Abdul Kadir MR, Sulaiman E, Abu Kasim NH
    Int J Oral Maxillofac Surg, 2012 Sep;41(9):1077-89.
    PMID: 22575179 DOI: 10.1016/j.ijom.2012.04.010
    The aim of this study was to compare two different types of surgical approaches, intrasinus and extramaxillary, for the placement of zygomatic implants to treat atrophic maxillae. A computational finite element simulation was used to analyze the strength of implant anchorage for both approaches in various occlusal loading locations. Three-dimensional models of the craniofacial structures surrounding a region of interest, soft tissue and framework were developed using computed tomography image datasets. The implants were modelled using computer-aided design software. The bone was assumed to be linear isotropic with a stiffness of 13.4 GPa, and the implants were assumed to be made of titanium with a stiffness of 110 GPa. Masseter forces of 300 N were applied at the zygomatic arch, and occlusal loads of 150 N were applied vertically onto the framework surface at different locations. The intrasinus approach demonstrated more satisfactory results and could be a viable treatment option. The extramaxillary approach could also be recommended as a reasonable treatment option, provided some improvements are made to address the cantilever effects seen with that approach.
    Matched MeSH terms: Dental Prosthesis Design/methods*
  17. Buzayan MM, Ariffin YT, Yunus N
    J Prosthodont, 2013 Oct;22(7):591-5.
    PMID: 23551843 DOI: 10.1111/jopr.12036
    A method is described for the fabrication of a closed hollow bulb obturator prosthesis using a hard thermoforming splint material and heat-cured acrylic resin. The technique allowed the thickness of the thermoformed bulb to be optimized for weight reduction, while the autopolymerized seal area was covered in heat-cured acrylic resin, thus eliminating potential leakage and discoloration. This technique permits the obturator prosthesis to be processed to completion from the wax trial denture without additional laboratory investing, flasking, and processing.
    Matched MeSH terms: Dental Prosthesis Design*
  18. Seow LL, Toh CG, Wilson NH
    Eur J Prosthodont Restor Dent, 2005 Jun;13(2):57-64.
    PMID: 16011232
    Existing literature suggests a relationship between the amount of remaining tooth structure and the fracture resistance of the restored endodontically treated tooth. This study investigated the amount of tooth structure remaining following various tooth preparations used in the restoration of the endodontically treated maxillary second premolar. Illustrations of the maxillary second premolar in buccopalatal, mesiodistal and occlusal sections were drawn to scale. Outlines of various intra- and extracoronal preparations were superim-posed on the illustrations to reveal the amount of tooth tissue remaining in each case. Preparations for a ceramic inlay, inlay with palatal cusp coverage and onlay left 2.0-2.5mm of tooth structure buccally and palatally. Following preparation for a metal-ceramic crown, approximately 1.0mm of tooth structure remained buccally, and between 1.6mm-1.8mm palatally. Preparation for an all-ceramic crown was observed to leave 1.0mm-1.2mm of tooth structure surrounding what remained of the endodontic access cavity. It was concluded that decisions as to the type of definitive restoration to restore the endodontically treated maxillary second premolar may be influenced, amongst other factors, by information on the amount of tooth tissue remaining following preparation.
    Matched MeSH terms: Dental Prosthesis Design*
  19. Rajan G, Baig MR, Nesan J, Subramanian J
    Indian J Dent Res, 2010 Jan-Mar;21(1):125-8.
    PMID: 20427922 DOI: 10.4103/0970-9290.62801
    Treatment of patients with aggressive periodontitis has always been a challenge to the clinician. Both young and old are known to be affected by this progressive destructive condition of the supporting dental structures. Although dental implants have been offered as a viable treatment alternative for such patients, additional procedures (like bone grafting) and delayed protocols have limited their usage. This case report describes the treatment of a young patient with aggressive periodontitis using a graftless implant solution. Zygoma implants in conjunction with conventional implants were used with immediate loading.
    Matched MeSH terms: Dental Prosthesis Design
  20. AL-Makramani BM, Razak AA, Abu-Hassan MI
    J Prosthodont, 2009 Aug;18(6):484-8.
    PMID: 19694015
    PURPOSE: This study investigated the occlusal fracture resistance of Turkom-Cerafused alumina compared to Procera AllCeram and In-Ceram all-ceramic restorations.

    MATERIALS AND METHODS: Sixmaster dies were duplicated from the prepared maxillary first premolar tooth using nonprecious metal alloy (Wiron 99). Ten copings of 0.6 mm thickness were fabricated from each type of ceramic, for a total of thirty copings. Two master dies were used for each group, and each of them was used to lute five copings. All groups were cemented with resin luting cement Panavia F according to manufacturer's instructions and received a static load of 5 kg during cementation. After 24 hours of distilled water storage at 37 degrees C, the copings were vertically compressed using a universal testing machine at a crosshead speed of 1 mm/min.

    RESULTS: The results of the present study showed the following mean loads at fracture: Turkom-Cera (2184 +/- 164 N), In-Ceram (2042 +/- 200 N), and Procera AllCeram (1954 +/- 211 N). ANOVA and Scheffe's post hoc test showed that the mean load at fracture of Turkom-Cera was significantly different from Procera AllCeram (p < 0.05). Scheffe's post hoc test showed no significant difference between the mean load at fracture of Turkom-Cera and In-Ceram or between the mean load at fracture of In-Ceram and Procera AllCeram.

    CONCLUSION: Because Turkom-Cera demonstrated equal to or higher loads at fracture than currently accepted all-ceramic materials, it would seem to be acceptable for fabrication of anterior and posterior ceramic crowns.

    Matched MeSH terms: Dental Prosthesis Design
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