| ObjectiveThere are important anatomical structures such as inferior alveolar nerve,submandibular gland,and maxillary sinus in the posterior region.It’s easy to cause tissue damage in these delicate structures during dental implant surgeries,resulting in an increased incidence of implantation complications and even failure of the whole implant surgeries.Therefore,how to improve the accuracy of implant surgeries is critically important.At present,most of the clinical comparisons between flap and flapless surgeries are based on these factors,such as the operation time,the amount of blood loss during the operation,patient satisfaction,etc.However,there are few comparative studies on the accuracy of the two types of surgery,which has been improved by the Computer Aided Design and Computer Aided Manufacturing(CAD/CAM)guides.In this experiment,CAD/CAM guides were used to assist the posterior dental implantation,and the accuracy of the two types of surgery was compared to provide a reference for selecting appropriate surgical procedures for clinical posterior dental implantation.MethodsCone beam computed tomography(CBCT)data and plaster model of 20 posterior teeth missing patients who underwent dental surgery in the Anhui Provincial Hospital Stomatology Center from October 2016 to October 2017 are used in this study.Those patients include 12 male patients,8 female patients,the age between 20-63 years,with a total of 24 missing teeth.The flap resin model is made according to the patient’s CBCT three-dimensional reconstruction image.The flapless resin model is made according to the three-dimensional reconstructed image after the patient’s CBCT image is fitted with the plaster model scan image.The CAD/CAM technology is used to make the surgical guide corresponding to each model.The in vitro simulation experiment is carried out with the aid of the guide.Register the ideal implant position before procedure and actual position after procedure in Mimics,then calculate the distance and angular deviation in this experiment,and compare the accuracy of the two procedures..P < 0.05 was considered statistically significant.Results1 The top deviation of the implanted flap surgery was(0.95±0.36)mm,the bottom deviation was(1.53±0.56)mm,the angular deviation was(3.45±1.10)°,and the depth deviation was(0.75±0.47)mm.2 The top deviation of the implanted flapless surgery was(1.33±0.43)mm,the bottom deviation was(1.94±0.30)mm,the angular deviation was(3.31±1.55)°,and the depth deviation was(1.43±0.41)mm..3 Comparison of flap and flapless surgery,the top deviation of the implant(t = 2.95,P = 0.007),the bottom deviation(t = 3.15,P = 0.005),depth deviation(t = 5.61,P = 0.000)and angle deviation(z = 0.371,P = 0.710).ConclusionIn this study,the dental implant surgeries were simulated on in vitro resin models,and the differences in accuracy between flap and flapless surgeries were compared.A total of 48 posterior dental implantations were simulated in the experiment,and the top deviation,the bottom deviation,the depth deviation,and the angular deviation between the long axis of the anterior and posterior implants were calculated.In contrast to the two surgical procedures,there was a statistical difference in the distance deviation,and no statistical difference in angular deviation.When CAD/CAM guides are used for assisting implantation,the flap surgery is more accurate than the flapless surgery in terms of distance deviation.However,we cannot suppose that the difference in surgical procedures will affect the accuracy of the angle. |
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