| case report rather, it happens around the very tip of the alveolar crest. Therefore, the highest stress and strain in a loaded im- plant occurs in the crestal part of the peri-implant bone.9 When the implant-to-bone interface is overloaded, a mi- cro-strain-induced crestal bone resorption can occur.10 This may add to a pre-existing implant pathology or facilitate the occurrence of a peri-implant disease. Load transfer management depends on the nature of the force applied and the contact surface distributing the forces to the bone. The bone is the most resilient to pressure and the least resilient to shear forces.11 Both macroscopic and microscopic properties of an implant body are important in their clinical performance. The microscopic component is very important in the ini- tial healing phase and early loading period. Surface treat- ment (e. g. sandblasting and acid-etching) increases the bone-to-implant contact by multiple times and facilitates healing.12 The macroscopic design is responsible for both early and delayed loading. Smooth surfaces on implant bodies increase the risk of bone loss because of non-ad- equate force transfer. These surfaces easily cause shear forces when loaded with masticatory forces.13 a loaded implant has the highest stress exhibited in the coronal 40 per cent of the implant-to-bone interface.17, 20, 21 Maintaining a favourable load distribution is not only beneficial for the implant-to-bone interface. Implant de- sign plays a major role in the deformations occurring in the implant-to-abutment assembly itself.22 The mechan- ical complications include abutment screw loosening, screw fractures, abutment fractures and, rarely, implant body fractures.23, 24 Regarding the occlusion-related factors, it is import- ant to note that the implant placement should be precise and prosthodontically driven, bearing in mind the biome- chanics of the final restoration. This means minimising the adverse leverage loads by centring implants in the mesiodistal plane, placing them perpendicular to the oc- clusal plane, choosing key implant positions and avoiding cantilevers (Figs. 1 & 2).24 Moreover, the occlusion must be well-balanced with particular regard to patients with high masticatory forces and parafunctional habits. Implant applied biomechanics Contemporary threaded implants have the capability to transform non-axial loading into a more favourable axial pressure force to the bone. When comparing implant de- signs, cylindrical implants have a greater functional sur- face for the load transfer to the bone than conical ones do. In such tapered implants, greater stresses are exhibited in the crestal bone. Biomechanical stress can be diminished with the correct choice of implant design, diameter, length and abutment and by thorough patient assessment.14–16 The aforementioned biomechanically significant prop- erties can be demonstrated on the basis of a GC Aadva Standard implant. This implant is made from Grade 5 tita- nium alloy (Ti-6Al-4V). The properties of the Grade 5 alloy have been proven mechanically advantageous, with its strength being significantly higher than in commercially pure titanium implants.25 In vitro results suggest that this implant is less prone to implant body fractures and could sustain higher masticatory forces. Studies on implant biomechanics have established nu- merous important facts for clinicians and manufacturers. Load distribution has been shown to be directly related to implant size and shape.17, 18 Implant width has a significant impact on bone-to-implant contact surface. For each mil- limetre of increase in implant diameter, the contact sur- face becomes larger by 30 to 200 per cent, depending on implant design.17 Since the functional surface is considered the most im- portant of all the design factors, one can conclude that the diameter of a loaded implant can greatly influence alveolar crest remodelling. Wide-diameter implants (up to 6.0 mm) have three and a half times greater bone stress reduction compared with narrow-diameter implants (3.5 mm). The greatest stress reduction is noted when increasing the im- plant diameter from 3.6 to 4.2 mm. The next stress reduc- tion, between 4.2 and 5.0 mm is half the previous amount. Furthermore, implant length, contrary to common belief, influences the functional surface less. A 10-mm cylindri- cal implant has about a 30 per cent greater surface than a 7-mm implant does and a 20 per cent smaller sur- face than a 13-mm implant.19 Analyses have shown that This could be the reason that the manufacturer does not contra-indicate the use of a narrow-diameter (3.3 mm) implant in premolar sites. However, the authors advise exercising caution in such applications and splinting the final restoration to another regular-platform implant. Al- though the narrow implant itself may withstand higher masticatory forces than usual, the loading of narrow im- plants in general can cause less than ideal force distribu- tion to the surrounding bone, as has already been men- tioned. If placed as a single-implant restoration, a 4 mm diameter implant would be preferred for the premolar region. Available diameters are 3.3, 4.0 and 5.0 mm, with lengths ranging from 6.0 to 14.0 mm. Another design trait of the regular GC Tech implant is the cylindrical implant body with slightly tapered threads to- wards the apex. The threaded cylindrical body is shaped to re-route and resist non-axial forces, while the discrete taper enables clinicians aiming for a more pronounced primary stability to achieve higher insertion torques. The surface is treated by sandblasting and acid- etching in an unconventional manner—there are three different sur- face regions, each with its own roughness, which may 20 2 2018