|Year : 2022 | Volume
| Issue : 1 | Page : 9-12
Platform switching technique: An updated review
V Pradeepkumar, Aruna Nautiyal, Shweta Bali, Priyanka Aggarwal
Department of Periodontics and Oral Implantology, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh, India
|Date of Submission||12-Apr-2022|
|Date of Acceptance||25-Apr-2022|
|Date of Web Publication||21-Jul-2022|
Department of Periodontics and Oral Implantology, Santosh Dental College and Hospital, Santosh Deemed to be University, Ghaziabad, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Modern dentistry aims to facilitate the patient to achieve excellent oral health. An ideal implant prosthesis can not only provide normal muscle activity, thereby improving the functions of mastication, but also improve esthetics profoundly. Among the factors involved to attain good esthetic result with implants, the correct positioning of the implant is one of the most important factors, along with preserving the integrity of gingival margins and interdental papillae. Preserving crestal bone is paramount, while planning for implant placement as it accumulates bacteria and leads to secondary peri-implantitis. Hence, the objective of this review article is to highlight the advantages of platform technique as compared to conventional treatment approach.
Keywords: Crestal bone level, implant–abutment interface, platform switching
|How to cite this article:|
Pradeepkumar V, Nautiyal A, Bali S, Aggarwal P. Platform switching technique: An updated review. Santosh Univ J Health Sci 2022;8:9-12
|How to cite this URL:|
Pradeepkumar V, Nautiyal A, Bali S, Aggarwal P. Platform switching technique: An updated review. Santosh Univ J Health Sci [serial online] 2022 [cited 2022 Dec 8];8:9-12. Available from: http://www.sujhs.org/text.asp?2022/8/1/9/351561
| Introduction|| |
Modern dentistry aims to facilitate the patient to achieve excellent oral health. The edentulous patient who has partial or complete missing dentition has disadvantages in mastication, esthetics, and phonation with the use of removable prosthesis. The masticatory efficiency of a removable denture user is reduced to about one-sixth when compared to that of natural dentition. An ideal implant prosthesis not only provides normal muscle activity but also improves the functions of mastication close to normal limits along with stimulating the bone and maintaining its dimension likely to healthy natural teeth. Among the factors involved to attain good esthetic result with implants, the correct positioning of the implant is one of the most important factors, along with establishing the optimum volume of hard and soft tissues. The peri-implant bone level is the major criteria to estimate the success of dental implants. It is an important prerequisite for preserving the integrity of gingival margins and interdental papillae. Preserving crestal bone is paramount when planning for implant placement as it can lead to increased bacterial colonization resulting in secondary peri-implantitis and bone loss hence resulting in occlusal overload resulting in implant failure. Apart from this, resorption of marginal bone will affect the gingival contours and may result in loss of interproximal papilla. Hence, the objective of this review article is to highlight the advantages of platform technique as compared to conventional treatment approach.
| History|| |
In the late 1980s, platform switching (PLS) was a serendipitous discovery; its benefits have in today's times become the prime focus of implant research with a significant consideration for preventing initial peri-implant bone loss. It so happened that due to the increased demands of wide diameter implants in the late 1980s, a scenario was created in which implants with ill-match standard diameter abutments were used due to lack of commercial availability of equal wide-diameter implants. This led to a form of treatment unintentionally labeled “change of platform,” which has come to be known as “PLS.”
As luck would have it, these implants exhibited an impressive property of inhibiting initial crestal bone loss. Several case reports implied improved soft and hard tissue responses to these platform-switched implants, hence encouraging many implant companies to integrate PLS into their systems for narrower body implants.
| The Concept|| |
PLS technique comprises placing narrower diameter restorative abutment on implants of wider diameter, rather than matching abutments of similar diameters [Figure 1]. These intended to increase the bone to implant contact in areas of limited bone height. At that time, the same dimension of prosthetic components was not easily available; hence, clinicians restored them with standard 4.1 mm diameter components, which provides a 0.45–0.95 mm circumferential horizontal difference in dimension between the implant seating surface and the attached component.
|Figure 1: Interaction between abutment and implant in regular implant and PLSI. PLSI = Platform-switching implants, IAJ = Implant–abutment junction|
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The interrelation between implant surface and its restorative abutment is termed the implant–abutment interface or “microgap.” In most cases, this creates micromovements during clinical function permitting microleakage of fluids [Figure 2]. This microleakage is permanently present as an area of abutment inflammatory cell infiltrate. This continuous state of inflammation encourages both osteoclast formation and activation contributing further to bone loss, to overcome this instead of using platform-matched implants, platform-switching implants (PLSI) protects microleakage of fluids and effective against infiltration of abutment inflammatory cells.
|Figure 2: Healthy and unhealthy soft and hard tissues on peri-implant area|
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PLS helps in biologic width extension and decrease in alveolar bone loss, hence influencing microgap on the crestal bone and reduces the stress levels around the peri-implant bone alongside enhancing the force in and around the screw.
- Anatomic structures limiting the residual bone height
- Implant placement in narrow edentulous ridge
- Situations with limited prosthetic space desiring larger diameter implants
- To achieve good esthetic results in anterior maxilla
- If shorter implants are used in atrophic areas. Contraindication: If normal-sized abutments are to be used, implants of larger size need to be placed. This might not be possible clinically always
- If normal implants are to be used, smaller diameter abutments may compromise the emergence profile in esthetic areas
- Close to 3 mm of soft tissue is needed to place platform-switched implants to avoid resorption or else bone resorption is likely to occur
- Undersizing of the components must be carried out during all phases of the implant treatment for the placement of PLS.
- Inflammatory cell infiltration takes place in implant–abutment junction (IAJ), forms collar-like fashion within the angle formed at the interface between implant seat and abutment, that prevents the apical migration of inflammatory cells, thus reduces the biological influence at the marginal bone
- Horizontal dimensions near interface and abutment allow additional connective tissue attachment, thus preventing remodeling of the crestal bone
- The influence of micro gap on bone resorption may be avoided by the soft tissue junction inward from the marginal bone.
- Good bone support is provided in the area where short implants are necessary when anatomical structures situated underneath, e.g., maxillary sinus and inferior alveolar bone.,
| Discussion|| |
Adell et al. in 1981 conducted a 15-year retrospective study to quantifying early crestal bone loss. They reported 1.2-mm marginal bone loss from the first thread during healing and in the 1st year after loading with an average 0.1-mm bone loss annually. Vertical bone loss (<0.2 mm) annually following the 1st year of implant function is the criteria for implant success as given by Smith and Zarb in 1989. A postrestorative remodeled crestal bone generally up to the level of the first thread on most standard diameter implants. The first thread changes the shear force of the crest module to a component of compressive force to which the bone is most resistant. Hermann et al. in 2007 reviewed biologic width, PLS, and implant design in the cervical region, nanoroughness, fine threads, insertion depths, abutment design, and elimination of microlesions in the peri implant soft tissue as factors that used for preservation of crestal bone levels. According to them, these factors along with several others determine the esthetic outcomes of implant restorations.
In 1997, Abrahamsson et al. in 1998 revealed that multiple screwing and unscrewing movements of the healing screw make the junctional epithelium moves toward apically around the implant collar. This reveals that this epithelial migration results, in turn, in an apical relocation of the bone level, so that a biologic width reconcilable with the health of the peri-implant tissues is restored. Biologic width completely forms within the first 6 weeks after the IAJ got introduced to the oral cavity. It is the barrier against bacterial invasion and food ingress at the implant–tissue interface. Gardner in 2005 demonstrated the literature dealing with the changes occurring during implant placement using PLSI. He suggested the main advantage being an excellent way to limit peri-implant circumferential bone loss and concluded that this technique needs further investigation. However, he quoted some potential disadvantages of this procedure such as the need for components with coinciding screw access holes and adequate space to maintain proper emergence profile. In a 3D finite element analysis, Hsu et al. in 2009 stated that PLS results to a small reduction of <10% in crestal bone strain. However, it does not significantly influence crestal bone strain or micromovement. Prosper et al. in 2009 in a randomized prospective study compared platform-switched implants and implants with an enlarged platform to cylindrical implants inserted with conventional surgical protocols having abutments of matching diameter. A significantly reduced postrestorative crestal bone loss was seen, when implants were placed in both two-stage and one-stage techniques. Cappiello et al. in 2008 confirmed the important role of the microgap between the implant and abutment in the remodeling of the peri-implant crestal bone. Platform switching seemed to reduce peri-implant crestal bone resorption and increase the long-term predictability of implant therapy. Canullo et al. observed that implants with platform-switching technique experienced significantly less marginal bone loss when compared to their conventional counterparts.
| Conclusion|| |
Many factors contribute to marginal bone loss around implants and its solution cannot be assigned to any single parameter. Crestal bone loss has been documented as one of the important factors that affect the long-term prognosis of a dental implant. Glimpsing through the available literature and reviewing it thoroughly, within the limitations of this article, we conclude that PLS significantly contributes not only to maintaining the width and height of crestal bone but also to limiting the bone loss circumferentially. This is to conclude that the implant design modifications in PLS technique offer many advantages, which include situations wherein a larger implant is desirable in a limited prosthetic space and especially in the anterior esthetic zones where crestal bone preservation can lead to enhanced esthetics.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]