Peri‐implant tissue health and patient satisfaction of vertical versus inclined posterior implants used to support overdentures with bar attachments. A one‐year randomized trial

Abstract

Introduction This study aimed to evaluate peri‐implant tissue health and patient satisfaction of vertical and inclined posterior implants for mandibular bar overdentures. Materials and methods Thirty edentulous participants received four implants in the interforaminal area of the mandible. The patients were randomly assigned into two equal groups; (1) vertical group (control): all implants were inserted vertically parallel to each other. Inclined group (study): the anterior implants were placed vertically, and the posterior implants were tilted 30° distally. Hader bar attachment with two 7 mm‐distal cantilevers (vertical group) and without cantilevers (inclined group) was used to connect the implants to mandibular overdentures. Peri‐implant tissue health (Plaque [PL] and gingival [GI] indices, pocket depth [PD], and crestal bone loss [CBL]) were evaluated after denture insertion (T0), 6 (T6), and 12 (T12) months after insertion. Patient satisfaction was evaluated using a visual analog scale after 12 months. Results At T12, the vertical group showed significantly higher PL, PD, and CBL than the inclined group for anterior (p < 0.037) and posterior (p < 0.017) implants. The vertical group showed significantly higher GI than the inclined group for anterior implants (p = 0.003), and the inclined group showed significantly higher GI than the vertical group for posterior implants (p = 0.016). The inclined group showed significantly higher scores for general satisfaction (p = 0.049), prosthesis as a part of you (p = 0.013), appearance (p < 0.001), stability (p = 0.002), ease of cleaning (p < 0.001), and comfort (p = 0.001) than the vertical group. Conclusion Inclined posterior implants used to support mandibular bar overdentures are recommended than vertical implants, as it was associated with improved patient satisfaction and peri‐implant tissue health.

Vertical versus angled immediately loaded implants for assisting maxillary overdentures with locator attachments: A preliminary results of one‐year randomized clinical trial

“…48 The vertical group recorded significantly higher crestal bone loss than the angled group at T12. This was in agreement with a study by Ibrahim and colleagues 49 who reported that distally tilted posterior implants supporting mandibular overdentures showed less peri-implant bone loss compared to vertically placed implants. The tilting of posterior implants increased anteriorposterior spread and offered better and wider load distribution.…”

“…The increased gingival inflammation may cause increased gingival enlargement which could be responsible for increased pocket depth. This finding was in line with Elsyad and colleagues, 47 Elsyad and colleagues, 48 and Ibrahim and colleagues 49 who found an increase in PD with the advancement of time for patients wearing implant‐supported overdentures. However, no statistically significant difference was found in PD between groups at all observation times.…”

“…In addition, the implant inclination decreases the cantilever length of denture saddles and reduces peri-implant bone stresses and bone loss. 49,52 The reduced peri-implant stresses with implant inclination were in line with earlier biomechanical research on "All-on-Four" implant configurations in delayed loading models. 52 The angled group showed higher satisfaction scores regarding stability and occlusion.…”

“…45,55 The improved comfort with the angled group compared to the vertical group may be attributed to the distal tilting of posterior implants, which enhances the anteroposterior spread and provides wide load distribution over a square region resembling a four-legged chair. 56 This finding was in line with a study by Ibrahim and colleagues 49 who reported higher patient satisfaction in angled implant-supporting mandibular overdentures.…”

“…This was consistent with the findings of other studies. 44,45,49 Additionally, the use of the tilted implants achieves good implant support with a favorable occlusal load distribution 44,53 which may enhance the chewing of hard food compared to the vertical group as patients usually prefer to eat using a distal occlusion because of their eating habits before teeth extraction. 54 With a wider inter-implant distance and enough access for oral hygiene procedures, the angled group showed a significantly higher ease of cleaning compared to the vertical group.…”