Abstract :
Purpose: The aim of this study was to evaluate and compare the clinical and radiographic outcomes of two implants
placed in expanded mandibular knife-edge ridge and implants placed in unexpanded ridges to retain overdentures.
Materials and methods: Fifteen completely edentulous patients with knife-edge ridges at canine areas of the mandible received
two implants using the ridge expansion technique (study group, SG). Expansion was performed using piezoelectric corticotomy,
and self-threading expanders. The control group (CG) comprised patients who received two-implant at canine areas without
ridge expansion but were all case matched to SG and served as historical cohort. In both groups, mandibular overdentures were
connected to the implants with Locator attachments 3 months after implant placement. Clinical (Plaque index; PI, Gingival
index; GI, Probing depth; PD, and implant stability; ISQ) and radiographic (Vertical bone loss; VBL) parameters were recorded
at time of overdenture insertion (base line, T0), 6 months (T6), and 12 months (T12) after insertion.
Results: The cumulative success rates were 100% and 96.4% for CG and SG, respectively, without significant difference
between groups. All tested parameters increased significantly with advance of time in both groups. There was no significant
difference in PI, GI, PD, and ISQ between groups. However, SG recorded significant higher VBL than CG at T6 and T12.
Conclusion: Expansion of mandibular knife edge ridge and simultaneous placement of implants to retain overdentures is
associated with clinic and radiographic outcomes comparable to implants placed in unexpanded ridges after 1 year.
However, long term randomized controlled trials with sufficient sample size are still needed to ensure the findings of the
present study.
KEY WORDS: implant, knife-edge ridge, mandibular, overdentures, ridge expansion
INTRODUCTION
The York consensus statement on overdentures1 concluded
that two implants placed in the interforaminal
region of the mandible to retain overdentures should be
the minimum standard of prosthetic care for edentulous
patients. Such treatment provides better retention, stability,
masticatory performance, patient satisfaction, quality
of life, and cost compared to conventional dentures. The
commonly used attachments for denture connection to
the implants are ball, bar, magnetic, and resilient telescopic
attachments.2 The locator attachments were introduced
in 2001. These attachments are resilient,3 selfaligning,
and available in different colors with different
retention values.4 Moreover, they have dual retention and
built-in angulation compensation.5 In addition Locators
can be used with limited interarch distance to reduce
denture base fractures thanks to their low profile.6
The long-standing mandibular edentulous ridge
undergoes accelerated bone loss especially at the labial
side of incisor and canine areas.7 The buccolingual
width of crestal bone decreases by 3.1 to 5.9 mm,
resulting in an estimated 60% loss of the original
*Faculty of Dentistry, Associate Professor, Removable Prosthodontics,
Department of Removable Prosthodontic, Mansoura University, Eldakahlia,
Egypt; †Faculty of Dentistry, Associate Professor Oral Surgery,
Future University, Cairo, Egypt
Corresponding Author: Mr. Moustafa Abdou ELsyad, Faculty of
Dentistry, Department of Removable Prosthodontic, Mansoura
University, P.O. Box: 35516, #68 ElGomhoria Street, ElMansoura,
Eldakahlia, Egypt; e-mail: [email protected]
VC 2016 Wiley Periodicals, Inc.
DOI 10.1111/cid.12436
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