Fundermental examination about support capability of dental implants at the bone developed by the maxillary sinus lift

2000 Fiscal Year Final Research Report Summary

• Project/Area Number: 11672007
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Showa University
• Principal Investigator: MANABE Masato Showa University, School of Dentistry, Assistant Professor (30190557)
• Co-Investigator(Kenkyū-buntansha): KAKUTA Saburou Showa University, School of Dentistry, Associate professor (40112726) ; YUI Kumie Showa University, School of Dentistry, Assistant Professor (50317583)
• Project Period (FY): 1999 – 2000
• Keywords: maxillary sinus lift / Frontal sinus / Autogenous bone / Hydroxiaptite / Tourue test / Titun implant

Research Abstract

The present study investigated the properties of bone tissue formed using various graft materials in maxillary sinus lift and elevation procedures. Newly formed bone was assessed in terms of viability as a supporting matrix for implants (mechanical properties) and histological affinity to implant bodies.
After shaving the rostral region of 4 Beagle dogs, a skin incision was made and a mucoperiosteal flap was created. The anterior walls of the frontal sinus on both sides were then exposed and an electrical dental engine was used to create openings measuring approximately 10 × 20 mm. The sinus membrane was elevated carefully to avoid tearing and bone grafting materials packed tightly into the space. The grafting materials were divided into 4 groups: Group 1, autogenous bone harvested from the mandible and ground into small pieces; Group 2, non-resorbable HA; Group 3, resorbable HA; and Group 4, autogenous bone mixed with HA. Each grafting material was placed in 2 separate locations in each of the experimental animals. Six months after the operation, tissue samples from the grafted sites were collected by trephination in order to prepare ^histological samples and 2 titanium implants were inserted into each of the grafted sites. Six months after placement, torque tests on the implants were conducted. Polished demineralized sections were also prepared in order to examine the differences in osseous tissue formed by the 4 bone grafting materials.
The autogenous bone graft group, the autogenous bone graft+HA group and the non-resorbable HA group gave torque values of 45N-cm, 41N-cm and 28N-cm, respectively. The torque value of the non-resorbable HA group was significantly lower in comparison to the two autogenous bone groups. The small number of test samples and the necessity to ensure consistency in the thickness of the cortical bone at the implant placement sites are factors that must be addressed in follow-up studies.