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1.
J Esthet Restor Dent ; 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38534043

ABSTRACT

AIM: The aim of this study was to compare the accuracy of full-arch conventional implant impressions using two different materials (A-silicone and polyether) to full-arch digital implant impressions produced from two intraoral scanning devices. MATERIALS AND METHODS: A master model was fabricated representing an edentulous mandible with four implants with internal connection placed at the sites of canines and first molars. The anterior implants were parallel to the residual ridge, while the two posterior implants had an angulation of 15° to the distal and 15° to the lingual respectively. The conventional technique was performed with open-tray of non-splinted impression copings. Two different impression materials were used, A-silicone and polyether at monophase medium body consistencies. The digital impressions were obtained with the use of two different intraoral scanners, after the connection of scan bodies. A total of 10 impressions were produced for each of the four experimental groups. The conventional models as well as the master model were digitized using a high-resolution laboratory scanner. The STL files of the models and of the intraoral impressions were imported in a powerful superimposition software, for the conduction of measurements in pairs of files. The software calculated the 3D deviations, as well as the linear and angular displacements among scan bodies at the digital files. For "trueness" measurements every STL file of each experimental group was superimposed to the digital master model, while for "precision" measurements all STL files of each experimental group were superimposed to each other. RESULTS AND CONCLUSIONS: The accuracy of full arch mandibular implant impressions was influenced both by the impression technique used (conventional vs. digital) and the impression material used (A-silicone vs. polyether) or the intraoral scanner used (Trios vs. Heron). In terms of "trueness," A-silicone showed the highest impression accuracy with the lowest deviation values, followed by polyether and Trios, but the differences between the three groups were in the majority not statistically significant. Heron showed statistically lower accuracy results in all measurements compared to the other groups. In terms of "precision", conventional impressions with the use of A-Silicone or polyether were statistically significantly superior to digital impressions with either scanner. A-Silicone and polyether showed no statistically significant difference between them.

2.
Gerodontology ; 41(2): 305-309, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38422399

ABSTRACT

OBJECTIVE: To describe the clinical procedures of complete denture set fabrication in three appointments. BACKGROUND: Simplified approaches have proven not to be inferior to conventional ones in terms of quality, patient satisfaction and masticatory ability. MATERIALS AND METHODS: The patient was a 77-year-old edentulous adult with mobility impairment seeking dental rehabilitation in a small number of appointments due to commuting difficulties. RESULTS: A set of complete dentures was delivered within three appointments. The second appointment was dedicated to set-up trial due to the patient's aesthetic demands. CONCLUSION: Under certain circumstances and after a thorough study of each case, dental clinicians may propose the fabrication of complete dentures in a three-appointment protocol incorporating a set-up trial session.


Subject(s)
Denture Design , Denture, Complete , Humans , Aged , Mouth, Edentulous/rehabilitation , Mobility Limitation , Male , Female , Appointments and Schedules , Dental Impression Technique
3.
Case Rep Dent ; 2023: 5249889, 2023.
Article in English | MEDLINE | ID: mdl-37621733

ABSTRACT

Implants are currently used to serve as abutments for implant-assisted removable partial dentures (IARPDs) to facilitate retention and support of the prosthesis. Implants are proposed in cases of posterior edentulous areas to convert Kennedy Class I or II to Class III or when the preparation of existing teeth to serve as abutments is contraindicated. The purpose of this report is to describe the protocol applied to fabricate an IARPD to restore a Kennedy Class II mandible of an elderly patient by incorporating traditional methods, such as the altered cast technique. Each step of the clinical procedure is thoroughly illustrated to document the selected appointment sequence. The patient was satisfied with the delivered prosthesis that demanded no additional implants to be placed but exploitation of an existing one. IARPDs are a viable and cost-effective solution substantiated by numerous reports with positive effects on patient satisfaction.

4.
Int J Comput Dent ; 0(0): 0, 2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37477084

ABSTRACT

AIM: The purpose of this systematic review and meta-analysis is to evaluate the marginal adaptation of single unit full coverage lithium disilicate fixed dental restorations fabricated with the conventional heat pressed technique and the digital CAD/CAM workflow. MATERIALS AND METHODS: This study is according to the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) statement. study research was conducted in MEDLINE via PubMed and Cochrane Library databases together with a hand search of studies published until June 2022. The search terms were combining suitable Medical Subject Headings (MeSH terms) together with free text words in single or multiple conjunctions. A modified methodological index was used to assess the risk of bias of the included studies. A random effect model was applied to pool the effect estimates, and further assessment of the heterogeneity across studies using the Q test and the I2 metric was conducted. All statistical analyses were performed using Rstudio software, version 4.1.2, using the "meta" package. RESULTS: The electronic search and hand search identified 51 articles. Eighteen met the inclusion criteria and were included in the systematic review, 17 of which were in vitro and only one was an in vivo study. However, 17 of the initial 18 could be included in the meta-analysis, due to lack of statistical data in one of the in vitro studies. Statistical analyses were conducted by using the Rstudio software program. Meta-analysis was performed with the random effects model (α=.05). No statistical difference was found between the two fabrication methods (p-value=0.49). CONCLUSIONS: Although the mean marginal adaptation of lithium disilicate single crowns was found to be better with the heat-pressed technique, there was no statistical significance with the CAD/CAM fabricated restorations and both resulted in a clinically acceptable result. Nonetheless, more clinical studies are needed for safer conclusions.

5.
J Esthet Restor Dent ; 35(8): 1205-1217, 2023 12.
Article in English | MEDLINE | ID: mdl-37381677

ABSTRACT

OBJECTIVE: The aim of this systematic review was to evaluate the influence of the characteristics of intraoral scan bodies (ISBs) on the accuracy of intraoral scanning. MATERIALS AND METHODS: An electronic search was conducted through PubMed (MEDLINE), Scopus and Cochrane Library, up to March 2023. The literature search intended to retrieve all relevant clinical and in vitro studies about the effect that the various properties of ISBs may have on the accuracy (trueness and precision) of intraoral scanning. Only publications in English language were selected with animal studies, case reports, case series, technique presentation articles and expert opinions being excluded. RESULTS: A total of 28 studies met the inclusion criteria and were included in this systematic review. They were published between 2019 and 2023 and were all in vitro studies. Among the parameters described, the scan body material, position, geometry, height, diameter, and fixation torque were evaluated. The most common materials used for ISBs were polyetheretherketone (PEEK) and titanium alloys. The diameter and position of ISBs seemed to affect the trueness of implant impressions. Subgingival implant position and decreased ISB height affected negatively the trueness of scanning. Geometrical characteristics of ISBs also affect the implant impression accuracy, especially the bevel location and the types of designing modifications. CONCLUSIONS: The characteristics of the currently used ISBs vary widely and the available scientific evidence is not yet conclusive about the optimal design of ISB. The implant impression accuracy achieved by any of the studied parameters is encouraging. Clinical studies are however necessary for more concrete conclusions. CLINICAL SIGNIFICANCE: ISBs play a vital role in the digital workflow and influence significantly the accuracy and fit of implant restorations. More clinical trials are needed in order to conclude to the optimal characteristics of ISBs which would further enhance the success of the restorations.


Subject(s)
Dental Implants , Dental Impression Technique , Computer-Aided Design , Research Design , Imaging, Three-Dimensional
6.
Spec Care Dentist ; 43(5): 666-670, 2023.
Article in English | MEDLINE | ID: mdl-36266778

ABSTRACT

BACKGROUND: The purpose of this clinical report is to present a technique for transformation of an existing removable partial denture (RPD) into a transitional complete denture (CD) for an impaired stroke patient. CASE PRESENTATION: A 67-year-old male who underwent an ischemic stroke 12 months ago presented in the Postgraduate Clinic of the National and Kapodistrian University of Athens, requiring treatment of his remaining teeth and repair of his existing RPD which lacked retention and stability. The treatment plan included placement of amalgam plugs on the remaining teeth which were decoronated due to poor prognosis and modification of the existing RPD to a transitional CD. The procedure included one alginate impression and chairside alteration of the prosthesis with simple means. The new prosthesis managed to improve patient's masticatory ability and reduce the risk for aspiration pneumonia. CONCLUSION: In the present case report a technique for modifying an existing RPD into a transitional CD for an impaired, stroke patient is described. Reduced treatment time, costs and patient's inconvenience while embracing the benefits provided by the utilization of an existing prosthesis regarding adaptation of the neuromuscular system are among the advantages of the described technique.

7.
J Prosthodont Res ; 67(3): 475-480, 2023 Jul 31.
Article in English | MEDLINE | ID: mdl-36244761

ABSTRACT

Purpose To describe a technique utilizing a novel prosthetic scan body, that assists the accurate merging of multiple scans (intra- and extraoral) of the interim prosthesis and edentulous arch with dental implants, during rehabilitation with a fixed implant-supported prosthesis.Methods Intraoral scanning (Trios 3, 3Shape) of an interim implant-supported prosthesis was performed, subsequently followed by another scan, using five scan bodies, placed onto the implant abutments (SRA, Bone level, Straumann AG). Successively, the newly designed prosthetic scan bodies were attached to the abutment copings of the interim prosthesis, for extraoral scanning. Utilizing an implant library designed for the prosthetic scan body, the three scans were merged, providing all the necessary information for the digital design and fabrication of the fixed implant-supported prosthesis.Conclusions The described clinical technique enabled effective and accurate superimposition of intra- and extraoral scans of the implant prosthesis. Superimposed data, including that of the position of dental implants and anatomy of soft tissue, provided essential information for the fabrication of a definitive implant-supported prosthesis. The novel prosthetic scan bodies attached to the implant prosthesis, assisted in merging intra- and extraoral scans, thus facilitating the rehabilitation of maxillary and/or mandibular edentulous dental arches. Further research is required to assess the accuracy of the proposed technique.


Subject(s)
Dental Implants , Mouth, Edentulous , Humans , Computer-Aided Design , Mouth, Edentulous/diagnostic imaging , Dental Care , Mandible , Dental Prosthesis, Implant-Supported
8.
J Esthet Restor Dent ; 35(3): 467-478, 2023 04.
Article in English | MEDLINE | ID: mdl-35929493

ABSTRACT

OBJECTIVE: To determine the effect of lifetime maxillofacial changes on dental implants placed in adults, analyze the clinical implications of these changes, identify prognostic factors, and offer possible solutions. OVERVIEW: The relationship between implant placement and maxillofacial changes, occurring during not only the active growth period but also the entire span of adulthood, has not been extensively examined. Vertical differences between implants and adjacent teeth due to the ankylotic behavior of the former might be observed at any age and endanger restoration biologically, functionally, and esthetically. Regarding interproximal contacts, firm contact loss may occur within a few months after restoration, resulting in food impaction. Many prognostic factors have been reported, but most do not exhibit a statistically significant association with implant infraocclusion and interproximal contact loss. Incorporation of alternative solutions, accurate treatment planning, strict recall protocols, and retrievability of implant-supported restorations can facilitate efficient management of complications. CONCLUSION: Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. Rehabilitation of edentulism should be characterized by well-designed and flexible treatment plans to resolve long-term complications efficiently. Further long-term clinical studies are needed to identify other risk factors. CLINICAL SIGNIFICANCE: Treatment plans for implant therapy should be reconsidered for adults. Careful patient monitoring and early intervention are essential for securing treatment outcomes.


Subject(s)
Alveolar Bone Loss , Dental Implants, Single-Tooth , Dental Implants , Tooth , Humans , Adult , Dental Implants/adverse effects , Dental Implantation, Endosseous , Treatment Outcome , Dental Prosthesis, Implant-Supported/adverse effects
9.
J Appl Oral Sci ; 29: e20200448, 2021.
Article in English | MEDLINE | ID: mdl-33787729

ABSTRACT

OBJECTIVE: Denture adhesives need complete removal due to their frequent replacement. Our study investigates the removal of denture adhesives from denture base materials, using different methods. METHODOLOGY: PMMA and Polyamide denture base materials were used to fabricate 120 samples (15×15×1.5mm). One side of the samples was left as processed and the other polished with a usual procedure, hydrated for 24 h, dried, and weighted. They received 0.2 g of three adhesive creams on their unpolished surface (Corega, Olivafix, Fittydent), pressed on polysulfide material, stored under 37°C and 95% rel. humidity for 1 h and 60 of them, following their separation from polysulfide base, brushed under running water, whereas the rest inserted in a cleanser bath (Fittydent Super) for 5 min. The samples were dried and inserted in the oven (37°C) for additional 10 min and weighted again. Roughness tests of denture materials and light microscopy of adhesives creams were also used to evaluate the materials. Time lapse images of spayed with water adhesives on PMMA base were also taken to evaluate the volumetric changes of adhesives. Weight data before and after adhesive removal, indicating the amount of remaining adhesive, were statistically analyzed using Welch's ANOVA and Games-Howell multiple comparisons tests at α=0.05 level of significance. RESULTS: Roughness of Polyamide was higher than PMMA and Fittydent showed greater volumetric changes than the others. Significant differences (p<0.05), were found between PMMA and Polyamide bases, between Olivafix and Fittydent adhesives, and between brushing and cleansing methods but only for PMMA-Olivafix combination. CONCLUSIONS: Adhesives showed a stronger adherence to PMMA surface, and Fittydent was the most difficult to be removed. Removal methods were not effective for all adhesives or denture base materials. These indicate that removal methods, adhesive type and denture base material are all playing a significant role in the removal of adhesives from denture surfaces.


Subject(s)
Denture Bases , Nylons , Adhesives , Materials Testing , Polymethyl Methacrylate , Surface Properties
10.
J Prosthet Dent ; 126(2): 262-263, 2021 08.
Article in English | MEDLINE | ID: mdl-32951869

Subject(s)
Dental Implants , Humans
11.
J. appl. oral sci ; 29: e20200448, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154618

ABSTRACT

Abstract Denture adhesives need complete removal due to their frequent replacement. Objective Our study investigates the removal of denture adhesives from denture base materials, using different methods. Methodology PMMA and Polyamide denture base materials were used to fabricate 120 samples (15×15×1.5mm). One side of the samples was left as processed and the other polished with a usual procedure, hydrated for 24 h, dried, and weighted. They received 0.2 g of three adhesive creams on their unpolished surface (Corega, Olivafix, Fittydent), pressed on polysulfide material, stored under 37°C and 95% rel. humidity for 1 h and 60 of them, following their separation from polysulfide base, brushed under running water, whereas the rest inserted in a cleanser bath (Fittydent Super) for 5 min. The samples were dried and inserted in the oven (37°C) for additional 10 min and weighted again. Roughness tests of denture materials and light microscopy of adhesives creams were also used to evaluate the materials. Time lapse images of spayed with water adhesives on PMMA base were also taken to evaluate the volumetric changes of adhesives. Weight data before and after adhesive removal, indicating the amount of remaining adhesive, were statistically analyzed using Welch's ANOVA and Games-Howell multiple comparisons tests at α=0.05 level of significance. Results Roughness of Polyamide was higher than PMMA and Fittydent showed greater volumetric changes than the others. Significant differences (p<0.05), were found between PMMA and Polyamide bases, between Olivafix and Fittydent adhesives, and between brushing and cleansing methods but only for PMMA-Olivafix combination. Conclusions Adhesives showed a stronger adherence to PMMA surface, and Fittydent was the most difficult to be removed. Removal methods were not effective for all adhesives or denture base materials. These indicate that removal methods, adhesive type and denture base material are all playing a significant role in the removal of adhesives from denture surfaces.


Subject(s)
Denture Bases , Nylons , Surface Properties , Materials Testing , Adhesives , Polymethyl Methacrylate
12.
J Prosthodont Res ; 64(2): 159-166, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31852607

ABSTRACT

PURPOSE: The purpose of study was to investigate the long-term effect of staining and/or cleansing solutions on the color stability of two non-metal removable partial denture materials. METHODS: One hundred disks (25×3mm) of polyoxymethylene (POM) and polyetheretherketone (PEEK) were immersed in water, wine, coffee, cleanser and combo bath, simulating normal daily use. Color parameters in the CIELAB system was measured every 30 cycles up to 240 using a contact colorimeter and color differences estimated using ΔEab and ΔE00 formulas. Two-way repeated measures ANOVAs and regression analyses were performed at α=0.05. RESULTS: Regression analysis indicated a strong R2 between color changes and number of cycles, for both materials. Tests of within-subjects effects for the ΔEab revealed significant differences among cycles and between the materials in the wine and coffee baths (p<0.001). Significant materialXcycles interactions were also recorded with all staining baths. ΔE00 values were lower than ΔEab up to 63.6%. Tests within and between-subjects effects for the ΔE00 gave similar but not the same with ΔEab results. CONCLUSIONS: ΔE00 found to correlate well with ΔEab. Long term exposure of both materials showed a progressive discoloration in all except control baths. POM discolored more than PEEK in coffee, and combo baths but not in cleanser. Discoloration was smaller in combo bath (where a cleanser was also used) indicating the effectiveness of a cleanser to prevent long term discoloration of both materials.


Subject(s)
Composite Resins , Dentures , Benzophenones , Color , Dental Materials , Ketones , Materials Testing , Polyethylene Glycols , Polymers , Staining and Labeling , Surface Properties
13.
Clin Oral Implants Res ; 29 Suppl 16: 270-275, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30328187

ABSTRACT

OBJECTIVES: The aim of Working Group 3 was to focus on three topics that were assessed using patient-reported outcome measures (PROMs). These topics included the following: (a) the aesthetics of tooth and implant-supported fixed dental prostheses focusing on partially edentulous patients, (b) a comparison of fixed and removable implant-retained prostheses for edentulous populations, and (c) immediate versus early/conventional loading of immediately placed implants in partially edentate patients. PROMs include ratings of satisfaction and oral health-related quality of life (QHRQoL), as well as other indicators, that is, pain, general health-related quality of life (e.g., SF-36). MATERIALS AND METHODS: The Consensus Conference Group 3 participants discussed the findings of the three systematic review manuscripts. Following comprehensive discussions, participants developed consensus statements and recommendations that were then discussed in larger plenary sessions. Following this, any necessary modifications were made and approved. RESULTS: Patients were very satisfied with the aesthetics of implant-supported fixed dental prostheses and the surrounding mucosa. Implant neck design, restorative material, or use of a provisional restoration did not influence patients' ratings. Edentulous patients highly rate both removable and fixed implant-supported prostheses. However, they rate their ability to maintain their oral hygiene significantly higher with the removable prosthesis. Both immediate provisionalization and conventional loading receive positive patient-reported outcomes. CONCLUSIONS: Patient-reported outcome measures should be gathered in every clinical study in which the outcomes of oral rehabilitation with dental implants are investigated. PROMs, such as patients' satisfaction and QHRQoL, should supplement other clinical parameters in our clinical definition of success.


Subject(s)
Dental Implants , Dental Prosthesis, Implant-Supported , Denture, Partial, Fixed , Esthetics, Dental , Jaw, Edentulous, Partially/surgery , Patient Reported Outcome Measures , Dental Prosthesis Design , Dental Restoration Failure , Denture Design , Denture, Partial, Removable , Humans , Immediate Dental Implant Loading , Patient Satisfaction , Quality of Life , Treatment Outcome
14.
J Esthet Restor Dent ; 24(3): 160-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22691076

ABSTRACT

UNLABELLED: Patient awareness of dental appearance has increased, resulting in more demanding esthetic requests. There is also strong evidence that increased esthetics is highly significant for complete denture acceptance and success. Taking notice of patients' perceptions of natural appearance and esthetics, the clinician can incorporate their preferences in the construction of individualized dentures that will be harmonized with their facial characteristics. Despite the evolution of materials and techniques, the vast majority of dentures still fail to look natural. Thus, producing prostheses that defy detection and successfully restore the appearance of edentulous patients remains a challenge for the clinician. This paper presents a clinical case where immediate loading of implants supporting a mandibular overdenture was combined with an opposing conventional maxillary denture to satisfy the high functional and esthetic demands of the patient. It also emphasizes the individualized esthetic performance through customization during their fabrication while taking into consideration the various clinical parameters affecting rehabilitation of the edentulous jaw. CLINICAL SIGNIFICANCE: Implant-retained overdentures can significantly improve the patients' function. The esthetic performance of these restorations however, may not be satisfying the patients' expectations and demands. Customizing the artificial gingival areas and individual staining of the prefabricated acrylic teeth may improve the esthetic performance creating natural-looking removable prostheses.


Subject(s)
Dental Prosthesis, Implant-Supported , Denture Design , Denture, Overlay , Esthetics, Dental , Immediate Dental Implant Loading , Denture, Complete, Upper , Denture, Partial, Removable , Female , Humans , Mandible , Middle Aged , Periodontal Prosthesis , Prosthesis Coloring , Retreatment , Tooth, Artificial
15.
Gen Dent ; 60(2): e47-54, 2012.
Article in English | MEDLINE | ID: mdl-22414517

ABSTRACT

When creating optimally esthetic contemporary prosthetic restorations, clinicians should balance patient preferences and requests with functional and esthetic demands. Beyond fulfilling the treatment objectives of restoring function and optimizing esthetics, the combination of fixed and removable dental prostheses should also blend seamlessly into the oral environment. Treatment planning and proper design of the prostheses is of paramount importance, while knowledge of material science and laboratory steps is needed to guarantee successful execution of clinical procedures. This article provides methods and techniques for improvement of the esthetic outcome through the description of clinical and laboratory steps of a clinical case.


Subject(s)
Denture Design , Denture, Partial, Fixed , Denture, Partial, Removable , Esthetics, Dental , Aged , Bite Force , Centric Relation , Denture Precision Attachment , Gingiva , Humans , Jaw Relation Record , Jaw, Edentulous, Partially/rehabilitation , Male , Patient Care Planning , Tooth, Artificial , Vertical Dimension
16.
J Oral Maxillofac Res ; 3(2): e5, 2012.
Article in English | MEDLINE | ID: mdl-24422012

ABSTRACT

BACKGROUND: The philosophy of a gradual transition to an implant retained prosthesis in cases of full-mouth or extensive rehabilitation usually involves a staged treatment concept. In this therapeutic approach, the placement of implants may sometimes be divided into phases. During a subsequent surgical phase of treatment, the pre-existing implants can serve as anchors for the surgical template. Those modified surgical templates help in the precise transferring of restorative information into the surgical field and guide the optimal three-dimensional implant positioning. METHODS: This article highlights the rationale of implant-retained surgical templates and illustrates them through the presentation of two clinical cases. The templates are duplicates of the provisional restorations and are secured to the existing implants through the utilization of implant mounts. RESULTS: This template design in such staged procedures provided stability in the surgical field and enhanced the accuracy in implant positioning based upon the planned restoration, thus ensuring predictable treatment outcomes. CONCLUSIONS: Successful rehabilitation lies in the correct sequence of surgical and prosthetic procedures. Whenever a staged approach of implant placement is planned, the clinician can effectively use the initially placed implants as anchors for the surgical template during the second phase of implant surgery.

17.
J Oral Maxillofac Res ; 1(1): e8, 2010.
Article in English | MEDLINE | ID: mdl-24421964

ABSTRACT

BACKGROUND: The hard and soft tissue deficiency is a limiting factor for the prosthetic restoration and any surgical attempt to correct the anatomic foundation needs to be precisely executed for optimal results. The purpose of this paper is to describe the clinical steps that are needed to confirm the treatment plan and allow its proper execution. METHODS: Team work and basic principles are emphasized in a step-by-step description of clinical methods and techniques. This clinical report describes the interdisciplinary approach in the rehabilitation of a partially edentulous patient. The importance of the transitional restoration which sets the guidelines for the proper execution of the treatment plan is especially emphasized along with all the steps that have to be followed. RESULTS: The clinical report describes the diagnostic arrangement of teeth, the ridge augmentation based on the diagnostic evaluation of the removable prosthesis, the implant placement with a surgical guide in the form of the removable partial denture duplicate and finally the special 2-piece design of the final fixed prosthesis. CONCLUSIONS: Clinical approach and prosthesis design described above offers a predictable way to restore partial edentulism with a fixed yet retrievable prosthesis, restoring soft tissue and teeth and avoiding an implant supported overdenture.

18.
Clin Oral Investig ; 8(4): 196-205, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15583918

ABSTRACT

BACKGROUND: Bone augmentation procedures in combination with dental implants enhance osseointegration in areas that demonstrate localized bone deficit. Clinical confirmation of a biomechanically stable interface is essential for functional implant loading. PURPOSE: The aim of this study was to evaluate biomechanically the effect of recombinant human bone morphogenetic protein (rhBMP)-2 on implant osseointegration and correlate it with periotest and radiographic measurements. MATERIALS AND METHODS: Hollow cylinder implants were filled with absorbable collagen sponge soaked with rhBMP-2 or left empty and implanted in dog mandibles. The animals were followed for 4, 8, and 12 weeks, periotest assessment was performed at the end of each time interval, and specimens were collected for pullout biomechanical testing and radiographic evaluation of bone-implant contact levels. RESULTS: Periotest assessment did not provide evidence of statistically significant differences between the two groups and correlated well with the radiographic bone-implant contact levels. The pullout test revealed a higher correlation between force/displacement and displacement/energy for the experimental group, suggesting that the addition of rhBMP-2 did influence the rate of osseointegration. CONCLUSION: The results from the pullout test support the potential role of rhBMP-2 in clinical applications by promoting a biomechanically mature interface at 12 weeks. However, radiographic and periotest assessment of the bone-implant interface did not provide evidence of the differences observed with biomechanical testing.


Subject(s)
Bone Morphogenetic Proteins/pharmacology , Dental Implants , Osseointegration/drug effects , Transforming Growth Factor beta/pharmacology , Animals , Biomechanical Phenomena , Bone Morphogenetic Protein 2 , Dental Prosthesis Design , Dogs , Drug Carriers , Gelatin Sponge, Absorbable , Humans , Male , Mandible/diagnostic imaging , Mandible/drug effects , Mandible/surgery , Osteotomy , Radiography , Recombinant Proteins , Stress, Mechanical , Surface Properties , Surgical Flaps , Time Factors
19.
Int J Oral Maxillofac Implants ; 19(5): 667-78, 2004.
Article in English | MEDLINE | ID: mdl-15508982

ABSTRACT

PURPOSE: To evaluate the effect of rhBMP-2 on implant osseointegration using histomorphometric and radiographic imaging analyses and determine the diagnostic accuracy of periapical radiographs regarding clinical bone-implant contact levels. MATERIALS AND METHODS: Hollow-cylinder implants were filled with an absorbable collagen sponge soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) or left empty and implanted in the mandibles of dogs. Animals were followed for 2, 4, 8, or 12 weeks. At the end of each time interval, the animals were sacrificed and specimens were collected for histomorphometric and radiographic evaluation of the bone-implant contact levels. RESULTS: Both groups exhibited the same mean histologic bone-implant contact on the outer surface of the implant, except for the 4-week group. The radiographic evaluation of bone-implant contact overestimated the actual osseointegration levels by at least 30%, a significant amount. DISCUSSION: The osteoinductive and regenerative potential of rhBMP-2 is of clinical benefit in cases where bone augmentation is indicated and improved levels of osseointegration are expected. Radiographic evaluation has been the most widely employed technique in clinical practice for assessing bone levels around dental implants and comparing changes over time. However, there is a limit to the diagnostic accuracy of conventional radiographs when compared to the data obtained by histologic analysis. CONCLUSION: Application of rhBMP-2 within the confined boundaries of the hollow chamber of the implant had a limited effect on the osseointegration level along its outer surface, perhaps because of physically restricted diffusion. Radiographic evaluation resulted in the overestimation of bone-implant contact, and poor correlation with the histomorphometric data was found.


Subject(s)
Bone Morphogenetic Proteins/therapeutic use , Dental Implants , Mandible/drug effects , Osseointegration/physiology , Transforming Growth Factor beta/therapeutic use , Animals , Bone Morphogenetic Protein 2 , Bone Regeneration/drug effects , Dental Implantation, Endosseous , Dental Prosthesis Design , Dogs , Drug Carriers , Gelatin Sponge, Absorbable , Humans , Image Processing, Computer-Assisted , Male , Mandible/diagnostic imaging , Mandible/pathology , Models, Animal , Osteogenesis/drug effects , Radiography , Recombinant Proteins , Time Factors , Titanium
20.
J Oral Sci ; 45(2): 57-73, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12930129

ABSTRACT

Bone Morphogenetic Proteins (BMPs) form a unique group of proteins within the Transforming Growth Factor beta (TGF-beta) superfamily of genes and have pivotal roles in the regulation of bone induction, maintenance and repair. They act through an autocrine or paracrine mechanism by binding to cell surface receptors and initiating a sequence of downstream events that have effects on various cell types. Differentiation of osteoprogenitor mesenchymal cells and up-regulation of osteoblastic features occur under the influence of cytokines and growth factors that are expressed with the direct or indirect guidance of BMPs acting at the transcriptional level or higher. The Smads family of proteins has been identified as the downstream propagator of BMP signals, whereas hedgehog genes are possible modulators of BMP expression. The inflammatory response observed during wound repair and fracture healing, results in by-products that interact with BMPs and affect their biologic potential. Additive, negative or synergistic effects are observed when homodimeric or heterodimeric forms of BMPs interact with BMP receptors. Storage within the bone matrix allows for their involvement in the modeling/remodeling process by mediating coupling of osteoblasts and osteoclasts. Micro-environmental conditions, dose, possible carrier materials and geometrical parameters of delivery matrix are critical determinants of the pharmacokinetics of BMP action and the biologic outcome during wound repair. Because of their osteogenic potential, BMPs are of tremendous interest as therapeutic agents for healing fractures of bones, preventing osteoporosis, treating periodontal defects and enhancing bone formation around alloplastic materials implanted in bone.


Subject(s)
Bone Morphogenetic Proteins/physiology , Bone Diseases/drug therapy , Bone Morphogenetic Proteins/therapeutic use , Bone Regeneration/physiology , Bone Remodeling/physiology , Humans , Osteogenesis/physiology , Transforming Growth Factor beta/physiology
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