Title There is No Greater Bone Loss Associated With Angled Implants Compared to Vertically Loaded Implants When Using Immediately Loaded Fixed Hybrid Prostheses
Clinical Question Is there a greater bone loss associated with angled implants compared to vertically loaded implants when using immediately loaded fixed hybrid prostheses?
Clinical Bottom Line For completely edentulous patients receiving an immediately loaded fixed hybrid prosthesis, there is no greater marginal bone loss associated with angled implants than with vertically loaded implants.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
25239770Chrcanovic/201444 studies: 5,029 tilted implants and 5,732 axial implantsMeta-Analysis
Key resultsThis systematic review and meta-analysis of published literature before July 2014 found that implant angulation of dental implants does not appear to affect marginal bone loss when compared to that of axially loaded implants (Mean Difference: 0.03, 95% CI -0.03 to 0.08; P=0.32). Included in the review were studies of both immediately and remotely loaded implants, supporting predominantly full-arch fixed hybrid prostheses. Only one of the included studies was a clinically controlled trial. The authors caution that the lack of standardized radiographic technique for measuring bone loss and the variability of follow-up period should be considered when interpreting the findings.
25536438Malo / 20151,296 implants at 5 yrs. serviceRetrospective case series
Key resultsAt 5 years of service, this more recent retrospective study with a large sample size found that tilted implants supporting immediately loaded fixed hybrid prostheses in 235 patients experienced 1.76 mm of mean marginal bone loss (standard error: 0.05; 95% CI: 1.64, 1.84) compared 1.74 mm bone loss (standard error: 0.06; 95% CI: 1.70, 1.92) for the companion axially loaded implants. The difference was not significant and appears to support the findings of the Chrcanovic meta-analysis.
24977252Del Fabbro/201419 studies: 1,338 tilted implants; 1,494 axially loadedSystematic review of non-randomized trials
Key resultsThis systematic review of published literature before January, 2014 found no significant difference at 1 year and at 3 years of function in crestal bone levels between axially and vertically loaded implants; P= 0.09, P=0.30 respectively. Other variables such as location (maxilla and mandible), loading mode (immediate vs. delayed), restoration type (full vs. partial) and study design (prospective vs. retrospective) had no effect on marginal bone loss. A total of 46 implants (18 axial and 28 tilted) failed in 38 patients within the first year of function. All failures except five occurred in the maxilla with a survival rate of 97.4% in the maxilla and 99.6% in the mandible. The authors concluded that tilted implants can be predictably used to support partial and full-arch fixed prostheses with an excellent short and mid-term prognosis.
25239770Patzelt/201413 studies: 4,804 implants; 1,201 prostheses Systematic review of non-randomized trials
Key resultsOut of 4,804 implants placed and immediately loaded with fixed hybrid prostheses in the studies included in this systematic review, only 1,575 implants were evaluated for bone level changes. The mean bone loss for all implants was 1.3 ± 0.4 mm (36 months) with no statistically significant differences encountered when comparing axially loaded versus tilted implants. The authors noted the lack of long-term follow-up studies of more than 5 years.
Evidence Search (("dental implants"[MeSH Terms] OR ("dental"[All Fields] AND "implants"[All Fields]) OR "dental implants"[All Fields]) AND tilted[All Fields] AND axial[All Fields]) AND systematic[sb]
Comments on
The Evidence
Validity: While the current short-term evidence supports the conclusion that there is no greater bone loss associated with angled implants compared to vertically loaded implants when using immediately loaded fixed hybrid prostheses, long-term data will be needed to add to the external validity. Confounding variables such as individual patients factors contributing to modes of failures will require further investigation to contribute to internal validation of the research. Perspective: While use of the All-On-4© concept is well supported in the literature, it might not be a viable option for all edentulous patients. Patient factors like smoking, past history of periodontitis, history of compliance, and maintenance intervals may influence long-term treatment prognosis and sustainability.
Applicability Angled implants can be utilized to avoid limiting anatomical structures and to improve the spread of implant support for immediately loaded full-arch fixed hybrid prostheses without negatively affecting marginal bone stability. Long-term data as well as quality current short-term data is still lacking, however.
Specialty (Oral Surgery) (Periodontics) (Prosthodontics)
Keywords All-on-Four, Hybrid, Axial implant, Tilted implants, Marginal bone loss.
ID# 3120
Date of submission 11/17/2016
E-mail ahmedi@uthscsa.edu
Author Isra Ahmed, DDS
Co-author(s)
Co-author(s) e-mail
Faculty mentor Stephan Haney, DDS
Faculty mentor e-mail haneys2@uthscsa.edu
   
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs)
None available