Guideline for success in early-loaded implant treatment

本研究旨在通过对不同改良表面的商用纯钛螺钉形种植体早期加载时间的评估，明确早期加载时间。将16个喷蚀改性表面钛(B)种植体、16个阳极氧化改性表面钛(O)种植体和16个机械表面钛(M)种植体分别置入成年雄性beagle犬的下颌无牙区。种植体放置1、3、6和12周后，通过设置冠状上部结构和硬颗粒食物来加载种植体。加载12周后，对每个种植体周围的骨组织进行组织学和组织学评估。所有种植体在组织学上均实现了骨与种植体的直接接触。在加载时间方面，3周组三种种植体的骨与种植体接触比（bic）和骨与种植体面积比（BIAs）均高于1、6、12周组。与A、M种植体1周组相比，3周组BIC明显升高（p<0.05）。1周组三种种植体的冠骨丢失较多。在三种不同种植体中，A种植体的BIC和B种植体的BIA均高于另外两种种植体。这些结果表明，对于表面改良的种植体，可能存在早期加载的最佳时间，并且在植入后3周可能开始加载，这与新形成的编织骨与种植体接触的骨愈合过程有关。

This study was designed to clarify favorable time of early loading for commercially pure titanium screw-shaped implants with different modified surface by evaluating bone-implant interface at several early times of loading. Each of 16 threaded blast-etched modified surface titanium (B) implants, 16 anodized modified surface (O) implants and 16 machined surface (M) implants was placed into the mandibular edentulous area of adult male 8 beagle dogs. After 1,3,6 and 12 weeks of implant placement, implants were loaded by setting crown-type superstructure with hard pellet food. After 12 weeks of loading, bone tissue around each implant was evaluated histologically and histometrically. Histologically direct bone contact to the implant was achieved in all implants. In terms of loading time, bone-to-implant contact ratios (BICs) and bone-to-implant area ratios (BIAs) of all three implants in the 3-week group were higher than those of the implants in 1,6,12-week groups. Significant higher BIC in the 3-week group was seen compared with these in the 1-week group of A and M implants (p<0.05). More loss of crestal bone of all three implants was seen in 1-week group. In terms of three kinds of different implants, BIC of A implant and BIA of B implant were higher than those of another two implants. These results suggest that optimal time of early loading may exist for the implant with modified surfaces and 3 weeks after placement are possible onset of loading associated with bone healing process with newly formed woven bone contact to the implant.