Primary implant stability in a bone model simulating clinical situations for the posterior maxilla: an in vitro study

Abstract

PurposeThe aim of this study was to determine the influence of anatomical conditions on primary stability in the models simulating posterior maxilla.MethodsPolyurethane blocks were designed to simulate monocortical (M) and bicortical (B) conditions. Each condition had four subgroups measuring 3 mm (M3, B3), 5 mm (M5, B5), 8 mm (M8, B8), and 12 mm (M12, B12) in residual bone height (RBH). After implant placement, the implant stability quotient (ISQ), Periotest value (PTV), insertion torque (IT), and reverse torque (RT) were measured. Two-factor ANOVA (two cortical conditions×four RBHs) and additional analyses for simple main effects were performed.ResultsA significant interaction between cortical condition and RBH was demonstrated for all methods measuring stability with two-factor ANOVA. In the analyses for simple main effects, ISQ and PTV were statistically higher in the bicortical groups than the corresponding monocortical groups, respectively. In the monocortical group, ISQ and PTV showed a statistically significant rise with increasing RBH. Measurements of IT and RT showed a similar tendency, measuring highest in the M3 group, followed by the M8, the M5, and the M12 groups. In the bicortical group, all variables showed a similar tendency, with different degrees of rise and decline. The B8 group showed the highest values, followed by the B12, the B5, and the B3 groups. The highest coefficient was demonstrated between ISQ and PTV.ConclusionsPrimary stability was enhanced by the presence of bicortex and increased RBH, which may be better demonstrated by ISQ and PTV than by IT and RT.

Insertion Torque of Variable‐Thread Tapered Implants in the Posterior Maxilla: A Clinical Study

“…Intentional sinus penetration by implants was reported by Brånemark as early as 1984. Animal and in vitro studies that conducted insertion/removal torque or resonance frequency analysis observed increased implant stability with bicortical anchorage compared to unicortical fixation. Conversely, Hsu et al reported that primary stability of implants with bicortical fixation did not significantly differ from that of implants with unicortical anchorage under clinical conditions.…”

“…Implant primary stability is a key factor in achieving osseointegration and is one of the prerequisites for successful immediate/early loading procedures. 1 Primary stability is affected by multiple factors such as bone quality, 2 bone density, 3 bone morphology, 4 implant design, 5 implant surface roughness, 6 preparation of the implant site, [5][6][7][8] crestal bone anchorage, 9 apical anchorage through the cortical floor of the sinus or nasal cavities, 10 lateral cortical anchorage, 11 and implant dimensions. 2,12,13 Optimal implant stability is more difficult to achieve in lowdensity bone, such as that of the posterior maxilla.…”

Sinus augmentation and concomitant implant placement in low bone‐density sites. A retrospective study on an undersized drilling protocol and primary stability

“…The insertion torque is the maximum torque needed to insert the implant in the placement site. This value may reflect average properties of the bone into which the implant is inserted (eg, average bone density), but it is also sensitive to local factors such as the presence of a cortical layer stabilizing the implant apically and/or coronally . The integral (I) instead measures the total energy exchanged between the implant and the surrounding bone during implant placement.…”

Bone characteristics and implant stability

“…3, No 1, 2017, pp. [18][19][20][21][22] Medical University of Varna ysis (18). According to their results the primary stability is influenced by the existence of cortical bone.…”

“…According to their results the primary stability is influenced by the existence of cortical bone. Han et al (19) inserted implants in artificial monocortical and bicortical bone blocks and found that the bicortical conditions could improve the primary stability.…”