Patient selection
edentulous, tooth
SYSTEMIC DISEASE, CREST
All partially edentulous patients needing two adjacent or contralateral implants in pristine bone in the maxillary premolar area were screened at the clinical centers for potential participation in this trial.General inclusion criteria were the following: (I) age >18 years; (II) good general health; (III) absence of systemic disease affecting bone metabolism and wound healing; (IV) no regular medication consumption for at least 3 months prior to treatment; (V) patient willingness and capability to fully comply with the study protocol; (VI) signed written informed consent.Local inclusion criteria were the following: (I) bone crest with a minimum of 6 mm width and 9 mm height above the maxillary sinus floor, with no concomitant or previous bone augmentation procedures; (II) healed bone crest (at least 6 months elapsed from tooth loss/extraction); (III) presence of opposing dentition.Exclusion criteria were: (I) absolute medical contraindications to implant surgeryAll patients received oral hygiene instruction and professional deplaquing 1 week prior to implant surgery.