What are the complications of implant dentures?

After 30 years of ups and downs, The implant dentures have finally developed into a relatively mature oral prosthodontics treatment, It has significantly improved the quality of life for some patients, which is gratifying; but It still has some problems, that is because different implant dentures restoration has a certain failure rate, and there is the possibility of complications existing in surgery, soft tissue, stent mechanics, pronunciation, and aesthetics, At the same time, the treatment of some complications is still in its infancy and research stage, therefore, Currently, The implant denture has gradually developed from the initial attempt to a practical stage in which the pros and cons must be weighed and a reasonable choice must be made in face of the specific cases. We must grasp the indications and contraindications of implant dentures. Before the implant placement operation, a detailed treatment plan should be formulated to prevent the occurrence of implant denture complications from every segment during the entire process from implantation to secondary restoration treatment. In addition, practical and effective measures and treatment plans should be taken as far as possible for the treatment of implant dentures that have occurred complications, to improve the success rate of implant dentures and restore their functions such as chewing and aesthetics. 

Clinical manifestations of complications of implant dentures

1. Surgical complications of implant dentures When implant surgery is performed for various dentition defects in the mandibular and posterior teeth, due to the special anatomical structure of the mandibular nerve, mental foramen, etc., accidental injury during surgery cause some complications. Such as nerve sensory disturbance, mandibular fracture, hematoma, bleeding, etc. According to reports in the literature: the highest rate of neurosensory disorders is 39%, the lowest is 0.6%, and the average is 6.1%. Most patients gradually resolved after one year, and a few developed persistent intractable neurological deficits after five years. Fractures of the mandible are rare and mostly occur in severely resorbed edentulous mandibles. For canines, the implantation of the first bicuspid may injure the lingual artery or branches, and further bleed into the mandibular space, thereby forming a hematoma. 

2. Many reports of marginal bone loss in implant dentures believe that the average marginal bone loss in the first year is 0.93mm, and the range is 0.4---1.6mm. After the first year of implantation, absorb 0.1mm per year, range: 0--0.2mm. Mild marginal bone loss after implant placement is a common phenomenon. It may be related to the following factors: heavy after subsidence, too tight during the implantation process to disperse the excessive stress to the marginal bone, or overload after repair. 

3. Complications of soft tissue complications of implant dentures are common: gingival cleft, atrophy, inflammation of teeth, hyperplasia, etc. Soft tissue inflammation often occurs around the abutment, below the rod, and further infection by anaerobic bacteria causes periodontal tissue inflammation: gingival redness, abscess, or peri-implantitis. Many scholars have reported that the occurrence of the ruffian tubes is often at the level of the connection between the implant and the foundation pile. It is related to poor oral hygiene or the formation of gaps caused by loose screws in the base teeth or caused by defects in workmanship. Gordioli believes that this soft tissue gap may be related to the deep position of the subgingival implant. 

4. Mechanical complications of implant dentures 

• Loosening of abutment screws, ranging from 2-45%, has the highest incidence in overdentures, followed by single teeth. 

• The loosening of the repairing screw occurs most often in single teeth, and the incidence in bicuspid and molar areas is greater than that in anterior teeth. One of the reasons is that because the abutment screws are made of titanium, there is an anti-torque between them. The problem is solved by using alloy abutment screws.