Gerard Torroella-Saura Javier Mareque-Bueno Josep Cabratosa-Termes ndez-Alfaro Federico Herna  Eduard Ferr es-Padro Jose Luis Calvo-Guirado

Authors’ affiliations: Gerard Torroella-Saura, Javier Mareque-Bueno, Federico Hern andez-Alfaro, Eduard Ferres-Padr o, Department of Oral and Maxillofacial Surgery, School of Dentistry, Universitat International de Catalunya, Barcelona, Spain Josep Cabratosa-Termes, Department of Prosthodontics, School of Dentistry, Universitat International de Catalunya, Barcelona, Spain Jose Luis Calvo-Guirado, Department of General and mplant Dentistry, School of Medicine and Dentistry, University of Murcia, Murcia, Spain Corresponding author: Gerard Torroella-Saura, DDS, MSc, PhD Department of Oral and Maxillofacial Surgery Dental School, Universitat Internacional de Catalunya Josep Trueta, s/n 08195 Sant Cugat del Vall es Barcelona, Spain Tel.: 34 935042000 Fax: 34 93276894 e-mail: [email protected]

Effect of implant design in immediate loading. A randomized, controlled, split-mouth, prospective clinical trial

Key words: edentulous mandible, immediate loading, implant design, insertion torque,

primary stability Abstract Objectives: The aim of this study was to evaluate the effect of two different designs, tapered vs cylindrical, on the primary stability of implants placed with an immediate loading protocol in edentulous mandibles to support fixed prostheses within occlusal contacts during the first 48 h. Material and methods: Tapered and cylindrical implants were placed in a split-mouth study using the same implant protocol in ten patients with edentulous jaws. A total of 20 tapered implants (test group) and 20 cylindrical implants (control group) were placed. All implants were loaded immediately with provisional fixed prostheses during the healing period before the final restoration. The implants were evaluated at the implant placement by analyzing the insertion torque values (ITVs) and the resonance frequency analysis (RFA) and after the healing period of three months, the success of those implants and the marginal bone loss were evaluated. Results: Two cylindrical implants were mobile within the same patient and no tapered implants failed, resulting in implant survival rates of 90% and 100%, respectively after three months. The ITVs were statistically significantly different (P = 0.0210) for the tapered implants than for the cylindrical implants. However, no statistically significant differences in RFA values were found (P = 0.6063) when comparing the implant designs and the primary stability measured with implant stability quotient (ISQ) values. The control group resulted in a mean bone loss after three months of 0.91 mm while the test group resulted 0.42 mm. Conclusion: The tapered implant achieved greater primary stability values measured with ITVs and less marginal bone loss than the cylindrical implants.

Date: Accepted 28 September 2014 To cite this article: Torroella-Saura G, Mareque-Bueno J, Cabratosa-Termes J, Hernandez-Alfaro F, Ferres-Padr o E, Calvo-Guirado JL. Effect of implant design in immediate loading. A randomized, controlled, split-mouth, prospective clinical trial. Clin. Oral Impl. Res. 00, 2014, 1–5. doi: 10.1111/clr.12506

Success of dental implants is mainly the result of primary implant stability following placement (Gapski et al. 2003; Sakoh et al. 2006; Roze et al. 2009). Primary stability is defined as the absence of movement of an implant after surgical insertion and it is influenced by many factors such as bone density and quality, surgical technique and implant body geometry (Olive & Aparicio 1990; Meredith 1998). Bone density has been considered by many authors as a crucial factor to determine the intra-osseous stabilization of dental implants at the time of implant placement, and in particular, cortical bone thickness is a key parameter for primary stability and clinical success (Lekholm 2003; Misch & Degidi 2003; Morton et al. 2004; O’Sullivan et al. 2004). Therefore, the use of a computed tomography (CT) scan as a noninvasive

© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

method can be recommended to determine preoperatively the density and architecture of bone in implant recipient sites (Song et al. 2009; Farre-Pages et al. 2011). However, existing literature (Akcßa et al. 2006; Roze et al. 2009) has suggested that the stability of an implant is related to the biomechanical properties of the adjacent bone. It has demonstrated a correlation between the amount of cortical bone and removal torque and concluded that dense cortical bone can provide better support for an implant than the less dense cancellous bone. The insertion of implants in an undersized osteotomy is another method to enhance the primary implant stability, which improves bone density and quality of the implant site. However, this technique has the disadvantage of being highly operator sensitive and subjective, which makes it difficult to

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Torroella-Saura et al  Effect of implant design in inmediate loading

quantify the degree of compression generated in the bone (O’Sullivan et al. 2004; Sakoh et al. 2006). The implant body design has been modified over the years to enhance primary stability, particularly for immediate loading, as the implant requires maximum stability at the time of the placement, and the bone has not had time to grow into recesses or undercuts in the implant body, or to attach to a surface condition before the application of occlusal load. Such modifications were introduction of self-tapping threads at the apical portion of the implant, increase implant diameter and length, modification of number of threads, type of threads and taper of the body of the implant. All these modifications have the common goal to increase the implant surface area in contact with the surrounding bone and engage marginal and lateral cortical bone to a greater extent (Misch et al. 2004). It is demonstrated that implant threads influence on the initial contact between implant and bone. Implants with more threads or narrow pitch patterns achieved greater implant primary stability values, as demonstrated in recent studies (Brinley et al. 2009; Orsini et al. 2009). Thread types can be square, V-shaped, and reverse buttress. The square thread shape has been designed to reduce shear forces at the implant-bone interface and increase implant stabilization. Achievement of acceptable initial intraosseous implant stability and maintenance within an asserted tolerable micromotion threshold of 50–150 lm are primary concerns during the healing period for immediate loading. Brunski (1993) found that the direct bone-implant interface may develop as long as the implant moved

Effect of implant design in immediate loading. A randomized, controlled, split-mouth, prospective clinical trial.

The aim of this study was to evaluate the effect of two different designs, tapered vs cylindrical, on the primary stability of implants placed with an...
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