The Clinical Analysis Of The Magnetic Attachments-Retained Complete Implant Overdenture In Edentulous Patients

Objectives:This research aimed to analyze the clinical applications of the magnetic attachments-retained complete implant overdenture in edentulous patients and the correlative factors, which would help rich the basic theory of clinical implant overdentuers and improve the implant successful rate.Methods:1. Cases selectionSeventeen edentulous patients with severely absorbed alveolar bones were selected in the implant center of the Stomatology Hospital of Shandong University from the September of 2003 to the May of 2010. There were three cases of maxillary jaw, and fifteen of mandibular jaw, including three cases with jaw defects; ten male and seven female, with the ages ranging from forty-seven years old to eighty-one years old (sixty-two years old on average). There were ten patients with periodontal disease, while seven patients had no history of periodontal disease. Effective periodontal treatments had been applied before the implant surgeries.2. Stage-Ⅰand Stage-Ⅱprocedure of the implant surgeryForty-seven implants were placed into the maxillary and mandibular bones, with two-four implants in every single jaw (two of the implants were Steri-Oss implant system, eight were ITI, seven were REPLACE, nine were OSSTEM and twenty-one were BLB). The Stage-Ⅱprocedure was applied two-six months after the Stage-Ⅰprocedure in accordance to the implant system.3. Prosthetic procedureThe magnetic attachments-retained complete implant overdentures were completed.4. Follow-upThe follow-ups were done 10-90 months after the Stage-Ⅰprocedure of the implant surgery. X-ray,probing and other clinical examination methods were used to evaluate the stability,function,the aesthetic effects,the shape of the soft tissues and the bone absorption of the implants. Complications were dealed with when needed.Results:1. The magnetic attachments-retained complete implant overdentures with two-four implants showed good effectiveness in the clinical application to edentulous patients with severely absorbed alveolar bones, with sufficient retention, stability, good masticatory and aesthetic effects. The effect was much more prominent in patients with edentulous mandibular jaws and jaw defects.2. The survival rate of all the forty-seven implants used in magnetic attachments-retained complete implant overdentures was 97.87% within the follow-ups of 10-90 months after the Stage-Ⅰprocedure. The survival rate of the eight implants in maxillary was 87.5%, while that of the thirty-nine implants in mandibular was 100%. The failure implant occurred in maxillary jaws.3. The results of the follow-up were as follows.①Clinical examination:Mobility (—), Percussion (—);②PD:2-3 mm on average;③X-ray:Stable ossteointegrations, with no obvious bone absorptions;④Peri-implant mucitis occurred in four implants, BOP (+);4. Within the follow-up of 10-90 months, the clinical effects of the magnetic attachments-retained complete implant overdentures in patients with periodontal diseases had no significant difference from those done to patients with periodontal diseases when effective periodontal treatments had been applied before the implant surgeries.5. The magnetic attachments-retained complete implant overdentures with two-four implants showed good effectiveness in the clinical application to edentulous patients with severely absorbed alveolar bones.6. The complications occurred within the follow-up and the relevant treatments were as follows.①Peri-implantitis occurred in one implant of one patient in maxillary jaws after the completion of ossteointegration.Treatment:The patient had additional implant surgery; the magnetic attachments-retained complete implant overdenture was recompleted.②One magnetic attachments-retained complete implant overdenture fractured from the median line.Treatment:The overdenture was remade, with mental netting to enhance.③Peri-implant mucitis occurred to four implants due to poor oral hygiene conditions.Treatment:Applications of local anti-biotics. The inflammation faded away gradullary.④The screws of the healing abutments of three implants fractured after the Stage-Ⅱprocedure of the implant surgery.⑤Discomfort occurred to one patient with no attached gingiva in the severed absorbed mandibular jaw.Conclusions:1. The magnetic attachments-retained complete implant overdentures with two-four implants showed good effectiveness in the clinical application to edentulous patients with severely absorbed alveolar bones, with sufficient retention, stability, good masticatory and aesthetic effects. The effect was much more prominent in patients with edentulous mandibular jaws and jaw defects.2. To improve the successful rate of the magnetic attachments-retained complete implant overdentures in the maxillary, we should pay attention to the following key points: ①Indications should be strictly selected, comprehensive oral examinations and risk assessment should be done prior to the surgery. Correlative factors such as the anatomical conditions of maxillary and mandibular jaws,the quantity and quality of the bones,the opposing jaws,the history of periodontal diseases and compliance of the patients should be considered before the surgery;②Trim the flabby ridges with surgery before the implant surgery;③Contol the distribution of occlusion force, avoid stress concentration, take proper measures to reduce the occlusion force, add the number of implants when needed, enlarge the overdenture base area and reduce non-axial force;④Stress the importance of regular follow-up, the best treatment for the complications are early diagnosis and early treatment.3. Within the follow-up of 10-90 months, the clinical effects of the magnetic attachments-retained complete implant overdentures in patients with periodontal diseases had no significant difference from those done to patients with periodontal diseases when effective periodontal treatments had been applied before the implant surgeries.