Computer Evaluation of the Changes of the Vestibular Bone Plate after Classical and Computer-Guided Delayed Implantation in Esthetic Zone

Abstract

BACKGROUND: The buccal bone plate as one of the key anatomical structures is of great importance for the success of implant therapy in the frontal maxilla and is particularly prone to changes that occur post-extraction. The condition of the buccal bone plate and its dimensions in the horizontal and vertical direction directly affects the method of implantation, the position of the implant, and the long-term results of the implant treatment. AIM: The aim of the study is to compare the differences and changes of the buccal bone plate in the anterior maxilla, during delayed implantation with and without the use of a surgical guide, which implies the use of different surgical techniques. Furthermore, the aim of this study is to determine their advantages and disadvantages. MATERIALS AND METHODS: To achieve the set goal, through CBCT images and computer software, changes in 40 patients divided into two groups were analyzed in three time periods: 20 patients who underwent delayed implantation in the anterior maxilla without a surgical guide and the second group of 20 patients who underwent delayed implantation using a surgical guide, which means that in the second group of patients, there  was no mucoperiosteal flap elevation. RESULTS: The analysis of changes in the buccal bone plate showed that the biggest changes were in patients who underwent delayed implantation according to the classical method and approach. The greatest changes in the horizontal dimension in the first group of patients (MI) were in positions 1, 3, and 6. Namely, for position 1, from an average horizontal dimension of 1.54 mm, the dimensions decreased to 0.26 mm during 12 months. On the contrary, in the second group, these dimensions recorded a slight decrease from 2.37 to 2.2 mm on average. At position 3, there was also a more developed resorption in the first group, from 1.54 mm to 0.88 mm, and in the second group, the resorption was insignificant and for the same period of 12 months, the horizontal dimension decreased from 2.27 mm to 2.12 mm, in which, clinically, it was not evident. Regarding the vertical dimension for 12 months in the first group, the resorptive changes ranged from 1.1 to 3.3 mm on average, while in the second group, changes in the vertical dimension were not observed, and they did not exist in the examined patients. The bone density in both groups decreased only in position 0 and much more in the first group where it decreased in a period of 12 months from 742 Hu to 150 Hu, while the decrease in the second group was from 1080.5 Hu to 1080 Hu. For all other dimensions, there is an increase in density in all time periods, higher in the second group. CONCLUSION: The obtained results showed that the greatest changes in the buccal bone plate in all dimensions occur during delayed implantation with a classical approach. This is mainly due to the position of the implants, as well as the disruption of the blood supply to the bone plate, which follows the creation of the flap.