The Three-dimensional Changes Of Soft And Bone Tissue Around Implants In Anterior Region

Objectives:The aim of this work was to measure the thickness of soft and bone tis-sue around dental implants by cone-beam computed tomography (CBCT) in order to investigate the three-dimensional changes of soft and bone tissue around peri-implant by retrospective study method in anterior region.Methods:The40patients suffering from teeth loss in anterior region were from Af-filiated Hospital of Stomatology, Medical College, Zhejiang University. Totally,44dental implants were inserted into these patients. After6-12months, in comparison to the contralateral contrast with the same teeth, the soft tissue index, included probing depth, modified plague index, modified sulcus bleeding index, PES aesthetic index and gingival biological type, were fully examined. The measuring points by CBCT for the soft tissue were lmm,2mm,3mm below gingival margin around dental implants and the soft tissue thickness for these points were marked as Al, A2, A3and A4, respec-tively. Also, the soft tissue thickness for the contralateral contrast with the same teeth were measured in the same points and marked as AMI, AM2, AM3and AM4, respec-tively. For the thickness of labial bone, the tested points were2mm,4mm,6mm below the implant neck, and were marked as G1, G2and G3. In the similar way, the measuring points for the contralateral contrast with the same teeth were2mm,4mm,6mm below the cementoenamel junction (CEJ) and were marked as GM1, GM2and GM3. Results:The average probing depth, sulcus bleeding index and plague index for dental implants was2.61±0.69mm,30.9±22(%),2.78±1.52, respectively, whereas1.49±0.66mm,35±18(%) and3.65±1.36for the contralateral contrast with the same teeth, respectively. The PES scores for the most patients were around10-13, except for5patients obtaining the highest PES score (14) and1patient getting the lowest PES score (9). The CBCT evaluation showed that the soft tissue thickness for Al, A2, A3and A4were1.22±0.68mm,1.92±0.83mm,2.62±0.78mm and2.66±0.78mm, respec-tively, whereas the bone tissue thickness for G1, G2and G3were1.86±0.79mm,2.19±0.96mm, and2.39±1.19mm, respectively. By Pearson correlation analysis, the data in-dicated that there was positive correlation between A2and G2/G3.Conclusion:After undergoing the loading for6-12months for the bone-level im-plants in anterior region, the stability for soft tissue around implants was positively cor-related to the thickness of labial bone around peri-implants.