Journal of Oral Implantology August 2014 - (Page 425)

RESEARCH Axial Relationship Between Dental Implants and Teeth/ Implants: A Radiographic Study Eli E. Machtei1* Orit Oettinger-Barak2 Jacob Horwitz3 The relationship of dental implants with neighboring teeth will affect both occlusal relationship and distribution of forces; thus, the purpose of this study was to examine implants' axial relationship with adjacent and opposing teeth/implants. Data of dental implants patients was retrieved. Panoramic X rays were digitized. Computerbased software was used to measure the angular relationship between the implants and adjacent/opposing teeth and implants. Data was further sorted by the mode of placement and implants position. 50 patients (219 implants) were included. Mean angle to adjacent tooth/implant was 178.718 6 9.188 (range 129.78-2068). Implants were more parallel to adjacent teeth (180.998 6 1.068) than to adjacent implants (176.328 6 0.548; P ¼ .0001). Mean angular relationship to opposite tooth was 167.888 6 8.928 (range 137.78-179.88). Implants that were placed freehand or with positional guide had similar intra-arch relationship (178.228 and 178.818, respectively) and similar inter-arch angulations (164.468 and 167.748). Molars had greater deviation of the angular relationship (175.548) compared to premolars (181.628) and incisors (180.558, P ¼ .0001). Implants placed in the maxilla had smaller axial deviation compared to implants in the mandible (180.418 6 0.64 vs 177.148 6 1.02; P ¼ .0081). Good axial relationship may be obtained in most implants placed by an experienced clinician, even when placed freehand. The mandibular posterior region is more prone to axial deviation and as such requires special attention. Key Words: dental implants, inclination, angulations, guides, stents, freehand INTRODUCTION C orrect implant placement involves complex biological and mechanical factors that must be considered for optimal implant success. Implant placement is a key factor in achieving satisfactory esthetics, a harmonious occlusion, and peri-implant health.1 Pellizzer et al2 have recently shown in a photoelastic analysis of stress distribution that the greater the angulation of an implant, 1 Division of Periodontology, Department of Oral Medicine Infection & Immunity, School of Dental Medicine, Harvard Medical Center, Boston, Mass. 2 Oral Health CRC, Melbourne Dental School, University of Melbourne, Carlton, VIC, Australia. 3 Rambam HCC School of Graduate Dentistry, and Faculty of Medicine, Technion - Israeli Institute of Technology, Haifa, Israel. * Corresponding author, e-mail: eli_machtei@hsdm.harvard.edu DOI: 10.1563/AAID-JOI-D-12-00052 the higher the stress it exerts on the cervical bone adjacent to the implant. The excessive occlusal forces that may result from unfavorable implant placement may cause marginal bone loss, implant or superstructure mechanical failure, or even complete loss of osseointegration.3-5 Implant axial angulation should be designed to allow prosthetic reconstruction that will direct the occlusal forces vertically. Perfect alignment is not always attainable due to anatomic limitations that hinder optimal position, such as limited inter-arch clearance that hinders the maneuverability of the surgeon, especially in posterior areas.6 Other operative factors that have been found to influence the mesiodistal implant angulation include the experience level of the surgeon, drilling speed, and the rate of increase in drilling diamete.7 To achieve the desirable implant position, a Journal of Oral Implantology 425

Table of Contents for the Digital Edition of Journal of Oral Implantology August 2014

Helping, Rather Than Criticizing, a Colleague May Lead to a Lifetime of Referrals
Utilization of Ethyl Cyanoacrylate and 2-Octyl Cyanoacrylate Adhesives for Autogenous Bone Graft Fixation: Histomorphometric Study in Rats
Conventional Versus Implant-Retained Overlay Dentures: A Pilot Study of Masseter and Anterior Temporalis Electromyography
Axial Relationship Between Dental Implants and Teeth/Implants: A Radiographic Study
The Effect of Dynamic Loading on Bacterial Colonization of the Dental Implant Fixture–Abutment Interface: An In Vitro Study
Longitudinal Implant Stability Measurements Based on Resonance Frequency Analysis After Placement in Healed or Regenerated Bone
A Clinical Report on the Use of Closed-Tray, Hex-Lock-Friction-Fit Implant Impression Copings
Immediate Restoration of NobelActive Implants Placed Into Fresh Extraction Sites in the Anterior Maxilla
Clinical Study of Flap Design to Increase the Keratinized Gingiva Around Implants: 4-Year Follow-Up
Use of Subepithelial Connective Tissue Graft as a Biological Barrier: A Human Clinical and Histologic Case Report
Calvarial Autogenous Bone Graft for Maxillary Ridge and Sinus Reconstruction for Rehabilitation With Dental Implants
Staged Ridge Splitting Technique for Horizontal Expansion in Mandible: A Case Report
An Overview of Zirconia Dental Implants: Basic Properties and Clinical Application of Three Cases
Dental Gypsum Verification Jig to Verify Implant Positions: A Clinical Report
Platelet-Rich Preparations to Improve Healing. Part I: Workable Options for Every Size Practice
Platelet-Rich Preparations to Improve Healing. Part II: Platelet Activation and Enrichment, Leukocyte Inclusion, and Other Selection Criteria

Journal of Oral Implantology August 2014