- Characteristics of study or subgroup
- Motoyoshi (a) [6]: self-drilling insertion with 1 point implant-root contact versus without implant-root contact
- Motoyoshi (b) [6]: self-drilling insertion with multiple implant-root contacts versus without implant-root contact
- Motoyoshi (c) [6]: pre-drilling insertion with 1 point implant-root contact versus without implant-root contact
- Motoyoshi (d) [6]: pre-drilling insertion with multiple implant-root contacts versus without implant-root contact