Platform Switching and Platform Bone Switching— Achieving bone health using Ditron implants Dr. Ole T. Jensen, DDS MS Osseointegration, restoration of function, and aesthetics are all the achievable goals of implant treatment. But to achieve these goals, clinicians must make all possible efforts to prevent bone loss and avoid microgaps that can harbor bacteria. Platform switching and platform bone switching are integral to implant longevity — minimizing both bone loss and bacterial growth. This white paper deﬁnes the basics of platform switching and platform bone switching and their involvement in the health of successfully placed dental implants. What is platform switching? alveolar crestal bone. A study by Drs. Yoshinobu In 2006, the concept of platform switching was Maeda, Jiro Miura, Ikuro Taki, and Motofumi Sogo introduced by Drs. Richard J. Lazzara and Stephan S. suggests that a platform-switching configuration has Porter. 1 lt is a “hardware” phenomenon. This is the biomechanical advantage of shifting the stress gained by inward displacement of the abutment from concentration area away from the cervical the implant platform which is in continuity with the bone-implant interface. Another beneficial result is alveolar bone crest. more protection from microflora. 1 Radiographic studies have shown a smaller than expected vertical crestal bone loss around platform- What is bone platform switching? switching implants than around implants that were The concept of bone platform switching arose from restored conventionally with prosthetic components the concept of hardware platform switching. Bone of matching diameters. This may be due to a greater platform switching involves the cervical two distance between implant abutment junction and millimeters of bone around an implant as a kind of separate conceptual entity though it is in continuity expose the titanium surface to bacterial with the alveolar bone. This conceptualization of Drs. contamination. The implication is that greater bone Francesco Carinci, Giorgio Brunelli, and Matteo Danza volume may hinder implant surface exposure. Also was studied as the most critical supporting bone problems associated with early implant surface around an dental implant. exposure have been correlated with late development of peri-implantitis. , Platform bone switching can be achieved by using a dental fixture with a reverse conical neck and Horizontal Thickness of the Cervical Ring therefore enhance this critical bone volume. Dr. In the best possible scenario, the thickness of Carinici and colleagues noted that an implant with a peri-implant bone around an implant should be conical neck offers several advantages: 10 greater than 1.7mm, with 2mm or greater bone thickness being the most ideal. However, in the • Reduced mechanical stress in the crestal alveolar anterior maxilla that would suggest an 8mm to 9mm bone area diameter site be required to place a 4.2mm diameter • Repositioning of gingival papillae on the bone ring implant which is often not available. To overcome • A more robust vascular supply to hard and bone this deficit bone grafting is commonly done facially tissue, also in cases of reduced inter-implant space. to increase bone thickness up to 2mm to 3mm to prevent implant surface exposure and help establish What is the Ring of Bone Concept? gingival form. The ring of bone concept describes the critical crestal bone at the neck of an implant for which Bone volume support for papilla near implants platform-bone switch and platform-abutment switch Cervical bone volume between implants that are help to define the quantity of supporting cervical 3mm apart does not greatly support a papilla. The bone volume. use of platform switch in side-by-side implants is When comparing a straight wall implant platform to not a factor for the hard tissue unless the implants a reverse conical neck platform, there is a significant are placed sub-crestally. With only minimal papilla difference at the crestal 2mm of bone support in support, if bone is lost to a sub-platform position, terms of bone volume preserved. any papilla could potentially become “punched out” Danza and Paracchini calculated the cubic volume of severely compromising esthetics and the ability to bone saved per implant using the reverse conical self-cleanse. neck implant to be 5.6mm. This is substantial bone Side by side reverse conical neck implants placed volume and is comprised of: level to the crest would lead to an addition of about .45mm between the implants or 3.45mm of space—a • The narrowing of the implant neck to 3.75mm from 15% improvement in bone preservation. If implants 4.2mm were placed slightly sub-crestally, the 0.5mm • The curved concavity of the neck itself platform switch would be additive for a 3.95mm • The 11 cervical grooves which additionally purpose a spacing, a 32% increase in cervical bone. small increase in bone volume. Abutment-implant junction Together, these increase viable crestal bone and help Cervical bone preservation is supported by accurate to keep cervical bone ring thickness above the fitting abutments. Precision fit at the abutment threshold where resorption becomes a greater risk to implant interface is very important. Junction movement from a poor fit can completely undermine abutment junction is 1mm to 1.4mm of potential any switching bone preservation strategy. bone loss. Hardware platform switch displaces the abutment junction slightly away from bone to reduce Zone of Inflammation the effect of inflammation on surrounding bone, the Abutment misfit or large gap width from a loose so-called distance-effect. The purpose of the abutment screw leads to abutment movement, platform bone switch is a bone volume-effect. This percolation of bacterial contaminates, and titanium method also reduces the chance for peri-implant metallic debris leading to the 1mm to 1.4mm zone of disease by increasing peri-implant bone volume inflammation. Bacterial composition in the which may inhibit or retard inflammatory bone implant-abutment connection is also affected by the resorption, delaying exposure of implant surface into precision fit and can contribute to marginal bone the oral cavity.7,8,9 loss magnitude. Efforts to reduce gap size to less than .5 microns to eliminate bacterial ingress are How Does This Relate to Implants? now achievable by using aerospace engineering The need for a narrow neck but a wider apical technology. One implant system, Ditron Dental USA, portion of an implant satisfies the dual need for the implant abutment gap was measured at less biomechanical retention and preservation of crestal than 0.5 microns which is smaller than typical bone. This is particularly important with extraction bacterial constituents of oral microflora. , , and immediate implant placement such as in the anterior maxilla. A reverse conical neck minimizes Prevention of Peri-Implant Disease encroachment on thin facial bone while at the same The cervical ring of bone is the first line of defense time maintains implant diameter apically to increase in the prevention of gingival recession and exposure primary stability for immediate temporization. of titanium potentially leading to peri-implant The design feature of the reverse conical neck has disease.8 become particularly beneficial in partially edentulous When cervical bone volume is thin (as little as 1.7mm areas with narrow spaces for implants and in as found in one study), especially in the maxillary segmental edentulous situations where there is anterior, or if the ring of bone is thin or interrupted, limited space for side-by-side implants. Instead of as is sometimes found with angled implant using narrow diameter implants to solve proximity placement, the body of the implant is more easily problems, a standard diameter implant can be used accessible to oral biofilm. However, as long as bone without adding substantial risk to marginal bone and is present up to platform level, particularly if there is papillary support while still maintaining needed healthy and adequate quantity of bone, the biomechanical advantage.5, “gateway” to peri-implant disease is closed. Ericsson et al. described histological inflammation Ditron Dental Implants around two-piece implants which must be Several implant manufacturers have recognized the considered in any bone preservation strategy. The benefit of narrowing the neck of the implant, but the authors found peri-implant inflammation to be of vast majority of implants are straight-walled and two types. often tapering outward, getting wider at the alveolar • Sulcular plaque-associated inflammation crest than the implant body, impacting cervical bone • Inflammation at the implant abutment junction dimension and potentially compromising ring of bone Radiographic evaluation demonstrates the zone of continuity. inflammation that develops over time at the Ditron Dental Implants achieve the goal of platform Summary bone switching in several ways. A tapered straight-wall implant and a reverse conical neck implant were compared at the cervical margin • The particular morphology of the collar, the Reverse in terms of bone volume of the cervical ring of bone. Conical Neck, increases implant contact surface area The reverse conical neck implant showed a with bone and preserves a greater proportion of substantial difference in ring of bone volume with an bone and periosteum. increase of 5.6mm.3 These findings suggest a • The taper and concavity of the collar reduces greater chance for maintaining adequate bone at the stress on the crestal cortical bone. margin of the implant which if otherwise lost could • By inserting an Ultimate™implant, 5.6 mm3 of bone lead to peri-implantitis. A precision fit (based on a 4.2mm diameter implant) will be abutment-implant junction, a sub-crestal platform preserved as compared to a straight wall implant. switch, the platform bone switch of the reverse • The Reverse Conical (and Concave) Neck provides concave neck and cervical micro-grooves all serve to greater implant stability and better distribution of increase and help maintain cervical bone volume to the stress at the bone implant interface. preserve critical marginal and subpapillary bone. 1 Lazzara RJ, Porter SS. Platform switching: a new concept J, Klinge B. Different types of inflammatory reactions in in implant dentistry for controlling postrestorative crestal peri-implant soft tissues. J Clin Periodontol. bone levels. Int J Periodontics Restorative Dent. 1995;22(3):255-261. doi: 10.1111/j.1600-051x.1995.tb00143.x. 2006;26(1):9-17.. 8 Carinci F, Brunelli G, Danza M. Platform switching and 2 Maeda Y, Miura J, Taki I, Sogo M. 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Ann Periodontol. 5 Danza M, Aollino I, Paracchini L, et al. Bone platform 2000;5(1):119-128. doi: 10.1902/annals.2000.5.1.119. switching in 3D Finite element analysis comparing standard 11 Atieh MA, Ibrahim HM, Atieh AH. Platform switching for and reverse conical neck implants. EDI Journal 2008, marginal bone preservation around dental implants: a 2-20110. 72. systematic review and meta-analysis. J Periodontol. 6 Widmark G, Andersson C, Ivanoff CJ. Mandibular bone 2010;81(10):1350-1366. doi: 10.1902/jop.2010.100232. graft in the anterior maxilla for single tooth implants: 12 Danza M, Palmieri A, Farinella F, Brunelli G, Carinci F, presentation of a surgical method. Int J Oral Maxillofac Girardi A, Spinelli G. Three-dimensional finite element Surg. 1997;26(2):106-109. analysis to detect stress distribution in spiral implants and 7 Ericsson I, Persson LG, Berglundh T, Marinello CP, Lindhe surrounding bone. Dent Res J. 2009;6(2):59–64.