Prospective randomized clinical trial of hydrophilic tapered implant placement at maxillary posterior area: 6 weeks and 12 weeks loading.
OBJECTIVE
Early loading of implant can be determined by excellent primary stability and characteristic of implant surface. The implant system with recently improved surface can have load application 4-6 weeks after installing in maxilla and mandible. This study evaluated the effect of healing period to the stability of hydrophilic tapered-type implant at maxillary posterior area.


METHODS
This study included 30 patients treated by hydrophilic tapered-type implants (total 41 implants at maxilla) and classified by two groups depending on healing period. Group 1 (11 patients, 15 implants) was a control group and the healing period was 12 weeks, and Group 2 (19 patients, 26 implants) was test group and the healing period was 6 weeks. Immediately after implant placement, at the first impression taking, implant stability was measured using Osstell Mentor. The patients also took periapical radiographs after restoration delivery, 12 months after restoration and final followup period. The marginal bone loss around the implants was measured using the periapical radiographs.


RESULTS
All implants were survived and success rate was 97.56%. The marginal bone loss was less than 1mm after 1 year postoperatively except the one implant. The stabilities of the implants were not correlated with age, healing period until loading, insertion torque (IT), the diameter of fixture and the location of implant. Only the quality of bone in group 2 (6 week) was correlated with the stability of implant.


CONCLUSIONS
Healing period of 6 weeks can make the similar clinical prognosis of implants to that of healing period of 12 weeks if bone quality is carefully considered in case of early loading.
Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Seong-Beom
0000-0002-9181-467X
SB
Kim
Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Pil-Young
0000-0001-6097-1229
PY
Yun
Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Sang-Yun
0000-0002-2952-5404
SY
Kim
Department of Prosthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.; Department of Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Yang-Jin
0000-0001-8341-4759
YJ
Yi
Department of Science Education, College of Education, Dankook University, Yongin, Republic of Korea.
Ji-Yun
0000-0001-6976-0743
JY
Kim
Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.; Department of Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
Young-Kyun
0000-0002-7268-3870
YK
Kim
Dental implant; Hydrophilicity; Survival rate