Combination of short implants and a unilateral distal-extension implant-retained partial denture in case of severely reduced ridge height mandibular posterior region: 12-year follow-up

Abstract

This case report describes the treatment of a woman who lost mandibular posterior teeth. The bilateral alveolar ridges showed severe tissue defects. She complained of the discomfort of a partial denture connected by a lingual bar and wished for fixed prostheses. However, the height of the alveolar bone was insufficient to place standard-length implants. In addition, she rejected bone augmentation and the usage of biomaterials. Therefore, short implants were placed in both sides of atrophic alveolar ridges without tissue augmentation. Conventional crowns were placed on the right side on three short implants, and a unilateral distal-extension partial implantretained partial denture (IRPD) using magnetic attachment was placed on the left side using the two available short implants. The patient was satisfied with the outcome of this treatment for 12 years even though a clasp was added to the removable partial denture at 11 years due to the wear of the magnet keepers. The combination of short implants and an IRPD using magnetic attachment is effective for patients with a severely atrophic posterior mandibular from the aspect of minimal intervention. 【 T h e Jo ur n al o f t h e A c a d em y o f Clinic al D e n t is t r y 3 7 (1・2): 7 2-8 0 ，2 017 】 Combination of short implants and a unilateral distal-extension implant-retained partial denture in case of severely reduced ridge height mandibular posterior region: 12-year follow-up

Retention of different types of attachments used with unilateral implant retained mandibular removable partial dentures.

“…As it is known the simpler the design of the partial denture, the better the results will be, this means that every component of the partial denture must have a good reason for its presence; otherwise, it must be omitted. A previous research considered that two implants were needed to avoid the use of a lingual bar and clasp on the premolar and to prevent rotation and displacement, it also concluded that using magnets as attachments with this design (without lingual bar or clasp) attained good clinical outcome for more than ten years [15]. For this reason, in the present study two implants were utilized to provide enough support and stability to the unilateral RPD.…”

“…It was stated that adequate retention could be achieved even though one of the implants was tilted [15]. In some cases of resorbed mandibular ridge, using posterior implants with distal angulation provides good bone support without interfering with vital structures [16].…”

“…Many mechanical complications have been reported in association with implant retained removable partial dentures [15]. Furthermore several case reports showed that small unilateral dentures can induce swallowing and aspiration [19,20].…”

Early Loading of Short and Standard-Length Dental Implants Retaining Mandibular Kennedy Class I Removable Partial Dentures

“…Immediate loading of short implants was reported in several studies of Alvira-González et al 38 , Weerapong K et al 42 , and Hadilou et al 45 However, this study adopted a more careful approach, the early loading, based on previous studies on the mandibular numerical models, 37 and bone density in the posterior mandible, 43,49,57 where the achieved primary stability of the short dental implants, together of one months of healing, the vertical placement of the implant, and the resilient attachment, enabled the short implants used in this study to demonstrate vertical bone loss values and surrounding bone density profile similar to the standard conventional long implants.…”

“…[19][20][21] Another controversial factor was the type of attachment of the implants to the IARPDS, where the ball abutments were found to transmit the least amount of stress to the implants and abutment teeth compared to locator and magnet attachments, when placed parallel to the most distal abutment, however, with reduced stability due to its greater freedom of movement, yet with more benefits and preservation of supporting teeth and implants when combined with mesially placed abutments. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] Immediate loading of short implants placed in distal extension edentulous spaces was considered an option in the treatment protocols, once primary stability could be achieved in selected cases, [38][39][40][41] also, no significant differences between the conventional loading and immediate loading of short implants were found, [42][43][44][45] with either locator or ball abutment attachments in follow-up periods extending from 2 to 12 years, [46][47][48][49] with preference of prognosis for implants placed in atrophic mandibles compared to atrophic maxillae. [50][51][52][53][54][55][56] Based on the previously presented data, this study aimed at clinical evaluation of early loaded short dental implants, compared to early loaded conventional long dental implants, supporting mandibular K...…”