[KAP-4] Crestal strain of 2-implant mandibular overdentures (2IMO) when implants placed at different positions and angulations: 3D-printed-simulation study
[Abstract]
Objective
To evaluate crestal strain of 2-implant mandibular overdentures (2IMO) when implants placed at different positions and angulations.
Methods
Edentulous mandibles were 3D-printed with two planned holes for implant placement at 5, 10, 15, and 20mm from midline (as 4 study-conditions), and with different angulations of 0/5, 0/10, 0/15, 5/5, 10/10, and 15/15 at 10mm (as 6 study-conditions). The complete dentures were 3D-printed and two 4.3x12.0mm implants were placed for all 10 study-conditions. Four linear strain-gauges [channels (CH)] were attached on peri-implant crest (CH4- right-distal, CH3- right-mesial, CH2- left-mesial, and CH1- left-distal) and connected to DCS-100A KYOWA computer-software. Male-Locators were attached, mucosal layer simulated, and denture was picked up with pink female-locator attachments. Bilateral force of 100N was maintained for 10 seconds under the universal testing machine (Shimadzu) while recording the strains. Data were analyzed by using 1-way-ANOVA, Tukey post-hoc, and paired-t test at significance level of P<.05.
Results and Discussion
Negative values indicates compressive-force, and positive indicates tensile-force. Both distal strain-gauges indicated an increasing trend of strains with an increase in implant position from midline. Strain-values for CH4 ranged between −166.08 with 5 mm and −251.58 with 20 mm position; and for CH1 between −168.08 with 5 mm and −297.83 with 20 mm position (P<.05). With changed angulations, strain-values for CH4 ranged between −146.83 with 0-5-degrees and −217.42 with 15-15-degrees. The strain-values for CH1 ranged between −169.58 with 0/5 degrees and −213.25 for the 15/15 degrees angulations with no significant differences. Changes in angulations didn’t cause significant changes except between 0/5 and 15/15 degrees (P<.05). Significantly higher (P<.05) strain-values were observed on the distal strain gauges than mesial. Peri-implant crestal strains in 2IMO increased with increasing implant-positions (significantly) and with increasing angulations (not significantly). Changed implant-positions had greater influence on peri-implant strains than changed angulations. Finite element analysis (FEA)1 using same 3D-models indicated similar trend, confirming the mechanical validation of FEA study.
References
1. Patil PG, Seow LL, Uddanwadikar R, et al. Stress and strain patterns of 2-implant mandibular overdentures with different positions and angulations of implants: A 3D finite element analysis study. J Prosthet Dent 2023;130(4):586-596.
Objective
To evaluate crestal strain of 2-implant mandibular overdentures (2IMO) when implants placed at different positions and angulations.
Methods
Edentulous mandibles were 3D-printed with two planned holes for implant placement at 5, 10, 15, and 20mm from midline (as 4 study-conditions), and with different angulations of 0/5, 0/10, 0/15, 5/5, 10/10, and 15/15 at 10mm (as 6 study-conditions). The complete dentures were 3D-printed and two 4.3x12.0mm implants were placed for all 10 study-conditions. Four linear strain-gauges [channels (CH)] were attached on peri-implant crest (CH4- right-distal, CH3- right-mesial, CH2- left-mesial, and CH1- left-distal) and connected to DCS-100A KYOWA computer-software. Male-Locators were attached, mucosal layer simulated, and denture was picked up with pink female-locator attachments. Bilateral force of 100N was maintained for 10 seconds under the universal testing machine (Shimadzu) while recording the strains. Data were analyzed by using 1-way-ANOVA, Tukey post-hoc, and paired-t test at significance level of P<.05.
Results and Discussion
Negative values indicates compressive-force, and positive indicates tensile-force. Both distal strain-gauges indicated an increasing trend of strains with an increase in implant position from midline. Strain-values for CH4 ranged between −166.08 with 5 mm and −251.58 with 20 mm position; and for CH1 between −168.08 with 5 mm and −297.83 with 20 mm position (P<.05). With changed angulations, strain-values for CH4 ranged between −146.83 with 0-5-degrees and −217.42 with 15-15-degrees. The strain-values for CH1 ranged between −169.58 with 0/5 degrees and −213.25 for the 15/15 degrees angulations with no significant differences. Changes in angulations didn’t cause significant changes except between 0/5 and 15/15 degrees (P<.05). Significantly higher (P<.05) strain-values were observed on the distal strain gauges than mesial. Peri-implant crestal strains in 2IMO increased with increasing implant-positions (significantly) and with increasing angulations (not significantly). Changed implant-positions had greater influence on peri-implant strains than changed angulations. Finite element analysis (FEA)1 using same 3D-models indicated similar trend, confirming the mechanical validation of FEA study.
References
1. Patil PG, Seow LL, Uddanwadikar R, et al. Stress and strain patterns of 2-implant mandibular overdentures with different positions and angulations of implants: A 3D finite element analysis study. J Prosthet Dent 2023;130(4):586-596.