| Backgroud:In the conventional oral implantation,several factors,such as the movement of the drilling pins,the limitation of surgery fields,3-D(three-dimensional)of bones,anatomy and aesthetic assessment,should be considered to insure the ideal implants positions.Surgeons should insert an implant into an ideal 3-D position in a restricted space;furthermore,if the bone quality were poor,extraordinary experience and skills were needed.Therefore,the implantation surgery was not easy at its first stage,and may even to injure the important anatomy structures;moreover,the second stage restorations were disadvantaged.Since the appearance of Cone Beam Computed Tomography(CBCT),the3-D images and mono-images could be present before the surgery,and from these,dentists can preferably understand the quality and quantity of the jawbone,and can insert implant in the virtual jawbones.Dentists can design the implant inserting point and inserting angles with suitable parameters before the surgery,and the post-surgery restorations,and thus,the navigation of dental implant guided plate was born.The dental implant guided plate can be divided into relatively simple Pioneer Drilling Guiding(PDG)and relatively complex Full Navigation Guiding(FNG).When the maxillary anterior region loss teeth,bone resorption occurring,and thus,leading to the shortage of the bone quality and quantity,and coupled with its aesthetic demanding in this area,the 3-D position of implant inserted in this area are highly requested.In the maxillary posterior region,the implantation is limited by the opening of mouth,the bone mass,the views and operability,which reduces the accuracy of the inserting site.With the guidance of digital implant guide,the dental implant can be further inserted into a more accurate position both in anterior and posterior regions,However,because of the above restrictions and transfer and processing errors in the guide-plate production,there is still a deviation in the root and neck distance,the depth and the inserting angle of the implant even if the implant is inserted under the navigation conditions.After the first drill,the PDG can adjust the directions and depths of implantation according to jawbone mass and adjacent teeth conditions,while the FNG requires higher accuracy,and the surgery can only be implanted according to preoperative designs.The two navigation systems have their own advantages and disadvantages,and their accuracy should be considered in addition to the patients jawbone conditions.At present,the studies of digital implant guide are mostly focus on the accuracy analysisbetween preoperative implant planning and actual postoperative implant site,and focus on the accuracy influence of operation and supporting modes to the guide plate.However,few studies were reported about the precision between pioneer drill navigation and full navigation,especially in different planting sites,and the researches between those are still blank.OBJECTIVES:This study is to compare the accuracy differences between the PDG and FNG technology in the maxillary anterior and posterior area separately,and to analyze the difference influencing factors.And in order to provide references for the clinical applications.METHODS:Separately,30 patients with missing maxillary anterior teeth and posterior teeth were randomly divided into the PDG group and the FNG group.After designing guide-plate depended on their CBCT dates,the implants were inserted according to their navigation modes,after that,the CBCT were taken again.At last,the deviations,which include the root and neck distance,the depth and the inserting angle,between the actual implant site and navigation guidance site were measured,and were statistically analyzed.RESULTS:PDG and FNG methods can both successfully complete implantation in the maxillary anterior and posterior areas,and can improve the accuracy of implantation.In the maxillary anterior region,in the PDG group and FNG group,the neck distance deviation were respectively 0.96±0.23 and 1.54±0.46,the root distance deviation were respectively 0.82±0.27 and 1.72±0.51,the depth deviation were respectively 0.60±0.21 and 0.77±0.18,and the inserting angle deviation were respectively 1.43±1.04 and1.62±0.83,and the PDG group was statistically lower than the FNG group in the root distance,the neck distance,and the depth(P<0.05),but the difference was not statistically with the inserting angle deviation between both groups(P>0.05).In the maxillary posterior region,in the PDG group and FNG group,the neck distance deviation were respectively 1.32±0.40 and 0.89±0.23,the root distance deviation were respectively 1.51±0.42 and 0.83±0.21,the depth deviation were respectively 0.60±0.21 and 0.77±0.18,and the inserting angle deviation were respectively1.58±0.97 and 1.49±1.02,and the FNG group was statistically lower than the PDG group in the root distance,the neck distance,and the depth(P<0.05),but the difference was not statistically with the inserting angle deviation between both groups(P<0.05).CONCLUSION:The use of PDG technique in the maxillary anterior region was more accurate than the FNG technique,while it was opposite in the maxillary posterior region.The more accuracy of the two navigation techniques is in the neck position deviation,the root position deviation,and the depth deviation,however,the difference in inserting angle deviation is not statistically significant.The choice of navigation techniques depends on the preoperative assessment,the implant site design which based on alveolar bone characteristics and operating space. |
