Int. J. Oral Maxillofac. Surg. 2014; 43: 606–625 http://dx.doi.org/10.1016/j.ijom.2013.12.004, available online at http://www.sciencedirect.com
Systematic Review Paper Dental Implants
Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review
I. Milinkovic, L. Cordaro Department of Periodontology and Prosthodontics, Eastman Dental Hospital, Rome, Italy
I. Milinkovic, L. Cordaro: Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review. Int. J. Oral Maxillofac. Surg. 2014; 43: 606–625. # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Bone resorption following tooth loss often interferes with dental implant placement in a desired position, and requires additional bone augmentation procedures. Many techniques have been described to augment and reconstruct alveolar ridge width and height. The aim of this study was to systemically review whether there is evidence to provide indications for the various bone augmentation procedures based on defect dimension and type. An electronic search of the Medline database and Cochrane library, complemented by a manual search, was performed. Inclusion criteria for partial edentulism were: clinical trials on bone augmentation procedures in preparation or at the time of implant placement, reporting preoperative and postoperative dimensions of the ridge. For edentulous patients, studies were included when providing the data on ridge and defect description, or the amount of augmentation achieved. The search yielded 53 publications for partially edentulous patients and 15 publications for edentulous patients. The literature provides evidence that dehiscence and fenestrations can be treated successfully with guided bone regeneration (GBR) at the time of implant placement (mean implant survival rate (MISR) 92.2%, mean complication rate (MCR) 4.99%). In partially edentulous ridges, when a horizontal defect is present, procedures such as staged GBR (MISR 100%, MCR 11.9%), bone block grafts (MISR 98.4%, MCR 6.3%), and ridge expansion/splitting (MISR 97.4%, MCR 6.8%) have proved to be effective. Vertical defects can be treated with simultaneous and staged GBR (MISR 98.9%, MCR 13.1% and MISR 100%, MCR 6.95%, respectively), bone block grafts (MISR 96.3%, MCR 8.1%), and distraction osteogenesis (MISR 98.2%, MCR 22.4%). In edentulous patients, there is evidence that bone block grafts can be used (MISR 87.75%), and that Le Fort I osteotomies can be applied (MISR 87.9%), but associated with a high complication rate. The objective of extracting specific indications for each procedure could not be fully achieved due to the heterogeneity of the studies available. Further studies on bone
0901-5027/050606 + 020 $36.00/0
# 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Indications for bone augmentation procedures
607
augmentation procedures should report precise preoperative and postoperative measurements to enable a more exact analysis of the augmentation procedure, as well as to provide the clinician with the rationale for choosing the most indicated surgical approach.
Key words: alveolar bone augmentation; indications; dental implants; systematic review.
The treatment of partial and total edentulism with dental implants has become a routine treatment modality in contemporary dental practice. Nevertheless, tooth loss is frequently associated with subsequent bone loss, often resulting in inadequate bone dimensions for dental implant placement in a prosthetically ideal position.1,2,3 Alveolar ridge resorption in partially and totally edentulous patients may interfere with the safe and correct positioning and placement of implants. When ridge resorption occurs, bone augmentation is essential to guarantee adequate bone volume, to provide patients with proper inter-arch dimensions, and to assure a satisfactory aesthetic result. Numerous reconstruction procedures have been proposed to increase alveolar bone dimensions, both vertically and horizontally, in order to obtain a sufficient ridge volume for adequate implant placement and prosthodontic rehabilitation.4–6 These techniques include: (1) guided bone regeneration (GBR); (2) bone block grafts; (3) distraction osteogenesis (DO); (4) ridge splitting or expansion; (5) osteotomies of the ridge or the jaws; and (6) combinations of the above. Several materials may be used in the aforementioned procedures, including autografts, allografts, xenografts, and alloplasts, as well as different barrier membranes or osteosynthesis materials. In some cases, bone augmentation procedures can be performed simultaneously with implant insertion, whereas in other clinical situations a healing period of the reconstructed ridge is needed, requiring a delayed, non-simultaneous implant placement. The long-term goal of both
The focused question was adapted using the PICO criteria: ‘‘In patients with inadequate ridge dimensions requiring dental implant treatment, which would be the preferred bone augmentation procedure for each clinical situation?’’ (Table 1).
one-stage and two-stage augmentation procedures is the stability of the augmented bone volume, allowing adequate function and optimal aesthetics, as expressed by implant survival, bone stability, and soft tissue stability. Hence numerous combinations of techniques and materials may be used and have been described in the literature.4–6 Usually a surgical technique should be chosen in relation to the anatomical baseline situation, the expected outcome based on scientific evidence, and the expected complication rate, as well as the expected success rate of the treatment with a given technique. It is not yet clear which procedure is an adequate choice for each particular clinical situation, providing satisfactory and stable bone dimension increase, long-term implant survival and stability, and a competent prosthetic rehabilitation. The objective of the present review was to explore, based on current publications, whether it is possible to extract clinical indications for the various bone augmentation procedures based on defect type and dimensions. Some clinical situations, such as immediate placement of implants in extraction sockets and sinus floor elevation, were not analyzed in the present review. Both clinical procedures have been addressed in numerous review papers and the indications have been thoroughly discussed.4,7–13 The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were adopted throughout the process of the present systematic review.14
Table 1. PICO criteria for the systematic review. Population (P) Patients who underwent bone augmentation procedures during preparation or at the time of implant placement Intervention (I) Horizontal and vertical bone augmentation procedures for partially edentulous patients, bone augmentation procedures in edentulous patients Comparison (C) Lack of indications for different bone augmentation procedures Outcome (O) Mean amount of augmentation, implant survival rate in the augmented bone, and occurrence of complications Focused question In patients with inadequate ridge dimensions requiring dental implant treatment, which would be the preferred bone augmentation procedure for each clinical situation?
Accepted for publication 18 December 2013 Available online 19 January 2014
Materials and methods Search strategy
A critical review of the literature was conducted to select pertinent full-length articles published in English. The most recent electronic search was undertaken on 1 June 2012. The electronic Medline (PubMed) and Cochrane Library search covered all human clinical trials conducted from 1990 to 2012 in which the above-mentioned bone augmentation procedures were performed. Additionally, a hand search of journals included the following: Clinical Oral Implants Research, Clinical Implant Dentistry and Related Research, Journal of Oral Implantology, International Journal of Oral and Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, Journal of Oral and Maxillofacial Surgery, International Journal of Oral and Maxillofacial Surgery, Clinical Oral Investigations, Implant Dentistry, Journal of Periodontology, Journal of Clinical Periodontology, Journal of Craniofacial Surgery, Journal of Oral Rehabilitation, Journal of Prosthetic Dentistry, and Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. Only publications in English on bone augmentation procedures were included in this systematic review. Search terms
A combination of the following search terms was utilized: bone atrophy, bone loss, alveolar ridge bone loss, alveolar ridge deficiency, fenestration, dehiscence, horizontal defect, vertical defect, preprosthetic surgery, bone augmentation, horizontal bone augmentation, vertical bone augmentation, GBR, resorbable membrane, non-resorbable membrane, autogenous bone graft, allograft, xenograft, alloplastic, distraction osteogenesis,
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Milinkovic and Cordaro
ridge splitting, split crest, Le Fort I osteotomy, bone graft, bone block, bone transplantation, follow-up, humans, dental implant, single-stage surgery, two-stage surgery, clinical trial, randomized controlled clinical trial, controlled clinical trial, prospective study, retrospective study. Selection criteria
The study protocol defined inclusion and exclusion criteria for study eligibility. Due to a reduced number of randomized controlled clinical trials, all clinical study types on human models were included in this review (randomized controlled clinical trials (RCT), controlled clinical trials (CCT), prospective studies (PS), and retrospective studies (RS)). Studies reporting not all outcome measurements but providing information on the augmentation procedure amount were also included. Inclusion criteria
The following inclusion criteria were applied: (1) Type of studies: all human clinical trials published in English, reporting on bone augmentation procedures during preparation or at the time of implant placement. (2) Type of defect: fenestration, dehiscence, horizontal and vertical ridge defects in partially edentulous and edentulous jaws. (3) Data included in the studies for partially edentulous patients: preoperative dimensions, postoperative dimensions of the ridge, or amount of augmentation, combined with a description of the defect. (4) Data included in the studies for edentulous patients: ridge and defect description, amount of augmentation. Exclusion criteria
The following exclusion criteria were applied: (1) Augmentations performed on implants placed at the time of tooth extraction (type 1, International Team for Implantology (ITI) classification) were excluded. (2) Sinus augmentations performed without an additional ridge augmentation procedure. (3) Studies not fulfilling the above-mentioned inclusion criteria. (4) Studies designed as case reports. (5) Studies describing techniques without reporting clinical outcomes. (6) Studies providing only histological data. (7) Studies describing bone augmentation procedures as a treatment modality following peri-implantitis, trauma, or tumour ablation, or therapy for various medical syndromes. (8) Publications in which the same data were published by the same groups of authors.
Data collection and analysis
Two independent reviewers screened titles and abstracts obtained through the described search. The screening was performed on a printout of the titles and abstracts according to the following criteria: human trials, longitudinal studies, clinical outcomes. Two reviewers evaluated the full-texts of studies of possible relevance. Any disagreement was discussed and resolved, and authors were contacted to provide, if possible, missing data. Kappa values for measuring agreement between two authors were equal to 0.86, thus reflecting excellent inter-author agreement. Outcome measures
The following treatment outcomes were recorded for the included studies: (1) Defect size pre- and postoperatively and/or the amount of augmentation (reported as defect fill or linear bone gain). (2) Survival and success rate of implants placed in the augmented sites. (3) Implant failure rate. (4) Complication rate. All the included studies were grouped and summarized according to: type of edentulism (partially edentulous or edentulous), defect type (fenestration, dehiscence, horizontal or vertical defect), and type of augmentation procedure applied. As a result of the former rationale, the results were grouped into partially edentulous patients and edentulous patients, as outlined below and shown in Fig. 1. Partially edentulous patients
(1) Horizontal augmentation group: GBR with simultaneous implant placement; GBR with non-simultaneous implant placement; bone blocks; ridge splitting and expansion. (2) Vertical augmentation group: GBR with simultaneous implant placement; GBR with non-simultaneous implant placement; bone blocks; distraction osteogenesis. Edentulous patients
Horizontal and vertical augmentation groups: GBR with simultaneous implant placement; bone blocks; ridge expansion; distraction osteogenesis; maxillary osteotomies. Statistics
No attempt was made to perform a metaanalysis of the data reported in the papers included in the present review, due to the heterogeneity of the data within a similar
group of clinical situations. In view of the heterogeneity of the data, it was not possible to perform an assessment of the risk of bias within studies. The mean survival and complication rates were calculated by weighted means. Results Partially edentulous patients: horizontal defects
Horizontal bone augmentation may be achieved with different techniques, including GBR, the use of bone blocks, or ridge expansion techniques. To assess if there is a clinical situation that indicates the preferred use of a surgical technique, some data are necessary. Dimensions of the residual ridge at baseline, bone augmentation achieved, and eventually implant outcome must be reported. It was decided to include only studies providing the aforementioned data. GBR and simultaneous implant placement for horizontal augmentation
An initial electronic search identified 938 titles when using the selected key words in terms of GBR techniques for bone augmentation. After final selection based on the abstract and full-text analysis, applying all the inclusion criteria, 15 full-text articles were extracted and included in this systematic review (Table 2). Out of the 15 studies included, four were RCT, one was a CCT, eight were PS, and two were RS. Regarding the type of defect, six papers reported on augmentation of dehiscence and fenestrations, seven on dehiscence only, one on fenestrations only, and one on alveolar ridge defects. In total, 683 patients received 1091 implants simultaneously with GBR augmentation procedures. Five studies reported on the use of resorbable membranes for GBR, five on the use of nonresorbable membranes, and in three studies both resorbable and non-resorbable membranes were used; in one study no membrane was applied within the GBR. One study reported on the use of titanium mesh as a membrane. In this study,15 15 patients were treated with 20 implants. Dehiscences were reconstructed with autograft and covered with titanium mesh as a membrane. Even though mesh should be considered only a space maintaining device and not a barrier membrane, this study has been included in this group. Various bone augmentation materials were used during the GBR procedures. In four of the included studies, the use
Indications for bone augmentation procedures
609
Fig. 1. Flowchart of the study selection process.PE: partially edentulous patients; Ed: edentulous patients; GBR: guided bone regeneration; GBR sim: guided bone regeneration and simultaneous implant placement; GBR non sim: guided bone regeneration and non-simultaneous implant placement; Split crest: ridge splitting/expansion; DO: distraction osteogenesis; Le Fort I: maxillary ridge augmentation and grafting in edentulous patients with Le Fort I osteotomy.
of autogenous bone was reported without the need for a secondary donor site, seven studies described the use of xenografts, one study the use of allograft, and two studies a combination of the various grafting materials. In two studies, no bone augmentation material was used; only the non-resorbable membrane was applied to the defect.16,17 The average preoperative dimension of a dehiscence and fenestration defect within the studies included was: 4.95 mm in horizontal dimension and 5.83 mm in vertical dimension. The average size of a postoperative defect decreased to 1.01 mm in horizontal dimension and 1.36 mm in vertical dimension, with a mean defect fill of 81.9%. Regarding the complications with the procedures used, Dahlin et al. reported an occurrence of flap dehiscences and graft exposure of 13%16 and Zitzmann et al. of 16% when using a resorbable membrane and 24.4% with a non-resorbable membrane,18 while Lorenzoni et al. reported the presence of dehiscence and membrane exposure, but did not define the frequency.17 In one study,19 defects treated with a collagen membrane had 17.4% of exposure, and with an expanded
polytetrafluoroethylene (e-PTFE) membrane, 12.5% of exposure. In a study by Blanco et al., dehiscence occurred in 11.5%.20 In a study by Hammerle and Lang, complications such as infection and necrosis occurred in 20%.21 In the study of De Boever and De Boever, complete defect coverage was found in 13 out of 15 patients (86.6%),22 and in the study by Widmark and Ivanoff, it was observed in 67%.23 Park et al. described dehiscence of the graft or membrane exposure in 24% of the sites.24 In a study by Dahlin et al., exposure was noticed around one implant (2.5%), and another one implant (2.5%) was lost.25 Four studies reported no dehiscence.26–29 The mean complication rate was 4.99%. The average healing time prior to implant loading was 6.8 months. The mean implant survival rate for implants simultaneously placed with the GBR procedure for horizontal augmentation was 92.2%. GBR and non-simultaneous implant placement for horizontal augmentation
Nine hundred and thirty-eight titles were extracted during the initial electronic
search when using the selected key words in terms of GBR techniques for bone augmentation. A refined search narrowed the selection to five full-text articles, which were extracted and included in this systematic review. Five studies met all the inclusion criteria, providing adequate data on preoperative and postoperative defect dimensions (Table 3). Out of the five studies included, one was an RCT, one was a CCT, and three were PS. Defects treated within these studies were described as presenting an initial ridge width that was not sufficient to place a standard-dimension dental implant. In total, 124 patients received 214 implants following the healing period after GBR augmentation procedures. Both resorbable and non-resorbable membranes were used in the analyzed articles. In three publications, a resorbable membrane was used, in one of them a non-resorbable membrane was applied, and one study reported on the use of both resorbable and non-resorbable membranes. Regarding the bone augmentation material applied, in two articles, the use of autogenous bone was reported, one study described the use of xenografts, one study the use of allograft, and one study the
610
Table 2. GBR with simultaneous implant placement for horizontal augmentation. Defect typey
Type of No. of No. of edentulismz patients implants
Site§
Dahlin et al. 199516 Fugazzotto 199726 Zitzmann et al. 199718
CCT Deh/Fen
PMx, PMd
RS
ND
331
626
Max/Mand
25
43
Max/Mand
4
Peleg et al. 199929
PS
Fen
8 EMx, 2 EMd, 12 PE PE
22
44
Max/Mand
5
von Arx and Kurt 199915 Lorenzoni et al. 199917
PS
Deh
PE
15
20
RS
Deh
Single PE, multiple PE, Ed PE
82
2 3
6
7
Deh/Fen
RCT Deh/Fen
Carpio RCT Deh/Fen et al. 200019 Deh/Fen Widmark and PS Ivanoff 200023
45
55
Techniqueô
Max/Mand
GBR
Augmentation (horizontal/ vertical)
Grafting material**
Membraneyy
Preop. dimension (mm)
Postop .dimension Defect (mm) fill (%)
Implant type
Implant placement Healing Follow-up (sim/ period Early Complication Survival Success Loading time non-sim)zz protocol (months) (months) failure rate (%) rate (%) rate (%)
H 1.2 mm
77
Bra˚nemark Sim
ND
4.5
24
3.64
13.00
84.7/93
ND
ND
ND
IMZ
ND
7.5
24
0.64
1.1
98.9
97.6
Measured in mm2 1.1/2.1
92 78
Bra˚nemark Sim
4 Mand 6 Max
5
55–70
2.4
24 16
97.6
ND
Mean 0.25
87
ND
5.6
ND
ND
0
ND
ND
V 6.2
V 0.4
93.5
Melsungen Sim/ Non-sim Sulzer Calcitek Straumann Sim
8.6
6.6
ND
0
5
95
ND
Non-res
V 2/10
ND
ND
Frialit
6
6
18
0
ND
100
ND
H 4.36/3.6, V 4.2/4.4 8.42 exposed threads
H 2.7/1, V 2/2 1.55 exposed threads
54 61 82
Implant Sim Innovations Nobel Sim Biocare
ND
6
ND
6
ND
12.5 17.4 ND
ND
ND
22 16.7 0
ND
ABG
Non-res/ Res None
100
ND
H
Xenograft
Res
Defect size H 0.7/0.66, V 0.6/0.79 H 0, V 2.5
97
Steri-Oss/ Calcitek
Sim
6–8
7
ND
12
None
100
ND
Res
Defect size H 4.3/4.07, V 6.7/6.36 H 0.5, V 3.6
86
Straumann Sim
6–7
6.5
ND
0
20
100
100
ND
2–3
60
1
ND
96.1
96.1
4
4
42
ND
6
94
ND
H
Membrane
Non-res
GBR
H H
Allograft + alloplast Xenograft
Non-res
GBR
GBR
H
ABG
Res
Defect size H 4.6 mm Deh 2–14, Fen 2–12 Measured in mm2 15.8/15.7 Mean 3.67
Max/Mand
GBR
H
ABG
Ti mesh
145
Max/Mand
GBR
H
Membrane
25 23 21
25 23 12
Max/Mand
GBR
H/V
ABG
Max/Mand
GBR
H
21
28
Max/Mand
GBR
Non-res/ Res
Sim
Sim
Nemcovsky et al. 200028
PS
Deh
14 PE single, 3 PE, 4 ED PE
10 Hammerle and Lang 200121 11 Blanco et al. 200520 12 De Boever and De Boever 200522 13 Park et al. 200824 14 Jung et al. 200927 15 Dahlin et al. 201025
PS
Deh
PE
10
10
Max/Mand
GBR
H
Xenograft
PS
Deh/Fen
PE
19
26
Max/Mand
GBR
H
V 3/12
V 0/2
60
PS
Deh
PE (single)
13
16
Max/Mand
GBR
H
ABG/allograft/ Non-res none Xenograft Non-res
V 3/9
V 0/2
97
Bra˚nemark/ Non-sim Straumann Straumann Sim
RCT Deh
PE (single)
22
26
Max/Mand
GBR
H
Allograft
Res
Sim
6
6
12
ND
ND
ND
ND
37
ND
Max/Mand
GBR
V/H
Xenograft
Res
V 1.42, H 1.61 ND
Zimmer
PE
6
6
12
ND
ND
ND
ND
20
40
ND
GBR
V/H
Xenograft
Non-res/ Res
94.9 96.4 67
Straumann Sim
Alv ridge PE defects
V H V V V
83
RCT Deh
Bra˚nemark Sim
7
7
53–72
ND
5
97.5
ND
8
9
PS
6.58, 3.48 5.95, 4.5 3.51
V 2.38
ND, no data; V, vertical; H, horizontal; Preop., preoperative; Postop., postoperative. *
Study type: RCT, randomized controlled clinical trial; CCT, controlled clinical trial; PS, prospective study; RS, retrospective study. Defect type: Deh, dehiscence type defect; Fen, fenestration type defect; Alv ridge defects, alveolar ridge defects. z Type of edentulism: PMx, partially edentulous maxilla; PMd, partially edentulous mandible; EMx, edentulous maxilla; EMd, edentulous mandible; PE, partially edentulous; Ed, edentulous. § Site: Max, maxilla; Mand, mandible. ô Technique: GBR, guided bone regeneration. ** Grafting material: ABG, autogenous bone graft. yy Membrane: Res, resorbable; Non-res, non-resorbable; Ti mesh, titanium mesh. zz Implant placement: Sim, simultaneous; Non-sim, non-simultaneous. y
Milinkovic and Cordaro
Study 1
Study type*
ND ND 0 ND ND 9–10
Bone blocks for horizontal augmentation
ND, no data; V, vertical; H, horizontal; Preop., preoperative; Postop., postoperative; Trans. par., transitional paresthesia. * Study type: RCT, randomized controlled clinical trial; CCT, controlled clinical trial; PS, prospective study. y Type of edentulism: PE, partially edentulous. z Site: Max, maxilla; Mand, mandible. § Technique: GBR, guided bone regeneration. ô Grafting material: ABG, autogenous bone graft; DBBM, deproteinized bovine bone mineral. ** Membrane: Res, resorbable; Non-res, non-resorbable; ePTFE, expanded polytetrafluoroethylene; PGA, polyglycolic acid. yy Implant placement: Non-sim, non-simultaneous. zz RCT/CCT, control group also presented in the table, but not included in the results and evaluation.
Non-sim Straumann Res Xenograft H GBR Max 15 12 H PS 5 Hammerle et al. 200830
H PS
PE
H GBR Max/ Mand 98 51
ND 15
4 Geurs et al. 200834
PE
44 15
PE (anterior max) H RCT 3 Meijndert et al. 200531
611
application of a collagen sponge as grafting material. The average preoperative dimension of a ridge width in the included studies was 2.9 mm. The average width of a postoperative ridge increased to 6.2 mm, resulting in a mean linear bone gain of 3.31 mm. When discussing the complication rate, three studies reported no complications during the healing period.30–32 Chiapasco et al. reported membrane exposure in 13.3%.33 Meijndert et al. reported fistulae in two patients and transitory paresthesia in one patient (13.3% and 6.6%, respectively, of the sample),31 while Geurs et al.34 reported fistulae in 6% of the cases, all successfully resolved. The mean complication rate was 11.9%. The average healing time before the implant placement was 7.7 months. The mean implant survival rate for implants non-simultaneously placed with the GBR procedure for horizontal augmentation was 100%. The implant survival rate was not reported in two studies.30,31
4
ND 100 6 0 12 6 ND Non-sim
H width of ND the crest 5.2 crestal, 7.5 apical 3.7 H width of the crest 6.9 Res (PGA)
H width of the crest 2.3 crestal, 4.3 apical H width of the crest 3.2
ND
90.9
96.1 ND 0
Trans. par.
ND 8.5
22.4
3 3
6
Gain Straumann of 2–5 Gain of 2–5 1–3 top of the crest
Non-sim
4 7.5 2.73
1. None 2. Res 3. Res
1. ABG (chin) 2. ABG + membrane 3. DBBM + membrane Allograft
ABG H
Bone blocks GBR
H
ND
93.3 100
100 0
13.3 0
0 12
18–36 6–8
12 9–40
6
Bra˚nemark, Non-sim Straumann Non-sim 2.7
Non-sim Straumann 2.5 H 5.5
7.7 3.17
H3
Non-res (ePTFE) Res
Res
Collagen sponge ABG H
H GBR
GBR
Max/ Mand Max/ Mand Max/ Mand Max 30
27 16
15 PE H CCT
PE H PS
1 Parodi et al., 199832 2 Chiapasco et al. 19993 zz
Grafting materialô Study
Type of No. of No. of Study Defect type* typey edentulismy patients implants
Sitez
Technique§
Augmentation (horizontal/ vertical)
Table 3. GBR with non-simultaneous implant placement for horizontal augmentation.
Membrane**
Preop. dimension (mm)
Linear Postop .dimension bone gain (mm)
Implant type
Implant placement Healing Follow-up (sim/ period Early Complication Survival Success time Loading yy non-sim) protocol (months) (months) failure rate (%) rate (%) rate (%)
Indications for bone augmentation procedures
An initial electronic search resulted in 239 titles when using the selected key words in terms of bone block grafts used for bone augmentation. After the final selection based on abstract analysis, eight full-text articles met all the inclusion criteria and were included in this systematic review (Table 4). Out of the eight studies included, two were RCT, one was a CCT, two were PS, and three were RS. Regarding the inclusion criteria for each study, some authors33–37 described initial horizontal defects numerically, usually as a ridge width less than 4 mm. In the remaining studies, the precise numerical initial defect description was missing, and the initial inclusion criterion was usually a ‘horizontal defect’ or ‘atrophic ridge’. Nevertheless, all included studies reported on precise preoperative ridge dimensions. In summary, 171 patients received 353 implants within a staged approach. The bone augmentation procedure used to correct the horizontally insufficient ridge was the use of bone blocks alone (four studies) or along with additional GBR procedures (four studies). For the additional GBR procedure, five studies reported on the application of autogenous bone chips, while two studies used an allograft, and in one study a xenograft was applied. Four studies reported on the use of resorbable membranes,33,37–39 one on the application of a non-resorbable membrane,35 and in two studies no membrane was used to
612
Table 4. Bone block grafts for horizontal ridge augmentation.
Max/ Bone Mand blocks + GBR Max/ Bone blocks Mand with Ti mesh
H
28
Max/ GBR Mand
H
15
44
Max/ Bone Mand blocks
H
PS
H less than 5
H
PE
40
66
RS
H 2.5–5, H in 5 cases less the 2.5
PE
18
27
PE
15
PE
H/V
3 Chiapasco CCT H
Systematic Review Paper Dental Implants
Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review
I. Milinkovic, L. Cordaro Department of Periodontology and Prosthodontics, Eastman Dental Hospital, Rome, Italy
I. Milinkovic, L. Cordaro: Are there specific indications for the different alveolar bone augmentation procedures for implant placement? A systematic review. Int. J. Oral Maxillofac. Surg. 2014; 43: 606–625. # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Bone resorption following tooth loss often interferes with dental implant placement in a desired position, and requires additional bone augmentation procedures. Many techniques have been described to augment and reconstruct alveolar ridge width and height. The aim of this study was to systemically review whether there is evidence to provide indications for the various bone augmentation procedures based on defect dimension and type. An electronic search of the Medline database and Cochrane library, complemented by a manual search, was performed. Inclusion criteria for partial edentulism were: clinical trials on bone augmentation procedures in preparation or at the time of implant placement, reporting preoperative and postoperative dimensions of the ridge. For edentulous patients, studies were included when providing the data on ridge and defect description, or the amount of augmentation achieved. The search yielded 53 publications for partially edentulous patients and 15 publications for edentulous patients. The literature provides evidence that dehiscence and fenestrations can be treated successfully with guided bone regeneration (GBR) at the time of implant placement (mean implant survival rate (MISR) 92.2%, mean complication rate (MCR) 4.99%). In partially edentulous ridges, when a horizontal defect is present, procedures such as staged GBR (MISR 100%, MCR 11.9%), bone block grafts (MISR 98.4%, MCR 6.3%), and ridge expansion/splitting (MISR 97.4%, MCR 6.8%) have proved to be effective. Vertical defects can be treated with simultaneous and staged GBR (MISR 98.9%, MCR 13.1% and MISR 100%, MCR 6.95%, respectively), bone block grafts (MISR 96.3%, MCR 8.1%), and distraction osteogenesis (MISR 98.2%, MCR 22.4%). In edentulous patients, there is evidence that bone block grafts can be used (MISR 87.75%), and that Le Fort I osteotomies can be applied (MISR 87.9%), but associated with a high complication rate. The objective of extracting specific indications for each procedure could not be fully achieved due to the heterogeneity of the studies available. Further studies on bone
0901-5027/050606 + 020 $36.00/0
# 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Indications for bone augmentation procedures
607
augmentation procedures should report precise preoperative and postoperative measurements to enable a more exact analysis of the augmentation procedure, as well as to provide the clinician with the rationale for choosing the most indicated surgical approach.
Key words: alveolar bone augmentation; indications; dental implants; systematic review.
The treatment of partial and total edentulism with dental implants has become a routine treatment modality in contemporary dental practice. Nevertheless, tooth loss is frequently associated with subsequent bone loss, often resulting in inadequate bone dimensions for dental implant placement in a prosthetically ideal position.1,2,3 Alveolar ridge resorption in partially and totally edentulous patients may interfere with the safe and correct positioning and placement of implants. When ridge resorption occurs, bone augmentation is essential to guarantee adequate bone volume, to provide patients with proper inter-arch dimensions, and to assure a satisfactory aesthetic result. Numerous reconstruction procedures have been proposed to increase alveolar bone dimensions, both vertically and horizontally, in order to obtain a sufficient ridge volume for adequate implant placement and prosthodontic rehabilitation.4–6 These techniques include: (1) guided bone regeneration (GBR); (2) bone block grafts; (3) distraction osteogenesis (DO); (4) ridge splitting or expansion; (5) osteotomies of the ridge or the jaws; and (6) combinations of the above. Several materials may be used in the aforementioned procedures, including autografts, allografts, xenografts, and alloplasts, as well as different barrier membranes or osteosynthesis materials. In some cases, bone augmentation procedures can be performed simultaneously with implant insertion, whereas in other clinical situations a healing period of the reconstructed ridge is needed, requiring a delayed, non-simultaneous implant placement. The long-term goal of both
The focused question was adapted using the PICO criteria: ‘‘In patients with inadequate ridge dimensions requiring dental implant treatment, which would be the preferred bone augmentation procedure for each clinical situation?’’ (Table 1).
one-stage and two-stage augmentation procedures is the stability of the augmented bone volume, allowing adequate function and optimal aesthetics, as expressed by implant survival, bone stability, and soft tissue stability. Hence numerous combinations of techniques and materials may be used and have been described in the literature.4–6 Usually a surgical technique should be chosen in relation to the anatomical baseline situation, the expected outcome based on scientific evidence, and the expected complication rate, as well as the expected success rate of the treatment with a given technique. It is not yet clear which procedure is an adequate choice for each particular clinical situation, providing satisfactory and stable bone dimension increase, long-term implant survival and stability, and a competent prosthetic rehabilitation. The objective of the present review was to explore, based on current publications, whether it is possible to extract clinical indications for the various bone augmentation procedures based on defect type and dimensions. Some clinical situations, such as immediate placement of implants in extraction sockets and sinus floor elevation, were not analyzed in the present review. Both clinical procedures have been addressed in numerous review papers and the indications have been thoroughly discussed.4,7–13 The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were adopted throughout the process of the present systematic review.14
Table 1. PICO criteria for the systematic review. Population (P) Patients who underwent bone augmentation procedures during preparation or at the time of implant placement Intervention (I) Horizontal and vertical bone augmentation procedures for partially edentulous patients, bone augmentation procedures in edentulous patients Comparison (C) Lack of indications for different bone augmentation procedures Outcome (O) Mean amount of augmentation, implant survival rate in the augmented bone, and occurrence of complications Focused question In patients with inadequate ridge dimensions requiring dental implant treatment, which would be the preferred bone augmentation procedure for each clinical situation?
Accepted for publication 18 December 2013 Available online 19 January 2014
Materials and methods Search strategy
A critical review of the literature was conducted to select pertinent full-length articles published in English. The most recent electronic search was undertaken on 1 June 2012. The electronic Medline (PubMed) and Cochrane Library search covered all human clinical trials conducted from 1990 to 2012 in which the above-mentioned bone augmentation procedures were performed. Additionally, a hand search of journals included the following: Clinical Oral Implants Research, Clinical Implant Dentistry and Related Research, Journal of Oral Implantology, International Journal of Oral and Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, Journal of Oral and Maxillofacial Surgery, International Journal of Oral and Maxillofacial Surgery, Clinical Oral Investigations, Implant Dentistry, Journal of Periodontology, Journal of Clinical Periodontology, Journal of Craniofacial Surgery, Journal of Oral Rehabilitation, Journal of Prosthetic Dentistry, and Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. Only publications in English on bone augmentation procedures were included in this systematic review. Search terms
A combination of the following search terms was utilized: bone atrophy, bone loss, alveolar ridge bone loss, alveolar ridge deficiency, fenestration, dehiscence, horizontal defect, vertical defect, preprosthetic surgery, bone augmentation, horizontal bone augmentation, vertical bone augmentation, GBR, resorbable membrane, non-resorbable membrane, autogenous bone graft, allograft, xenograft, alloplastic, distraction osteogenesis,
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ridge splitting, split crest, Le Fort I osteotomy, bone graft, bone block, bone transplantation, follow-up, humans, dental implant, single-stage surgery, two-stage surgery, clinical trial, randomized controlled clinical trial, controlled clinical trial, prospective study, retrospective study. Selection criteria
The study protocol defined inclusion and exclusion criteria for study eligibility. Due to a reduced number of randomized controlled clinical trials, all clinical study types on human models were included in this review (randomized controlled clinical trials (RCT), controlled clinical trials (CCT), prospective studies (PS), and retrospective studies (RS)). Studies reporting not all outcome measurements but providing information on the augmentation procedure amount were also included. Inclusion criteria
The following inclusion criteria were applied: (1) Type of studies: all human clinical trials published in English, reporting on bone augmentation procedures during preparation or at the time of implant placement. (2) Type of defect: fenestration, dehiscence, horizontal and vertical ridge defects in partially edentulous and edentulous jaws. (3) Data included in the studies for partially edentulous patients: preoperative dimensions, postoperative dimensions of the ridge, or amount of augmentation, combined with a description of the defect. (4) Data included in the studies for edentulous patients: ridge and defect description, amount of augmentation. Exclusion criteria
The following exclusion criteria were applied: (1) Augmentations performed on implants placed at the time of tooth extraction (type 1, International Team for Implantology (ITI) classification) were excluded. (2) Sinus augmentations performed without an additional ridge augmentation procedure. (3) Studies not fulfilling the above-mentioned inclusion criteria. (4) Studies designed as case reports. (5) Studies describing techniques without reporting clinical outcomes. (6) Studies providing only histological data. (7) Studies describing bone augmentation procedures as a treatment modality following peri-implantitis, trauma, or tumour ablation, or therapy for various medical syndromes. (8) Publications in which the same data were published by the same groups of authors.
Data collection and analysis
Two independent reviewers screened titles and abstracts obtained through the described search. The screening was performed on a printout of the titles and abstracts according to the following criteria: human trials, longitudinal studies, clinical outcomes. Two reviewers evaluated the full-texts of studies of possible relevance. Any disagreement was discussed and resolved, and authors were contacted to provide, if possible, missing data. Kappa values for measuring agreement between two authors were equal to 0.86, thus reflecting excellent inter-author agreement. Outcome measures
The following treatment outcomes were recorded for the included studies: (1) Defect size pre- and postoperatively and/or the amount of augmentation (reported as defect fill or linear bone gain). (2) Survival and success rate of implants placed in the augmented sites. (3) Implant failure rate. (4) Complication rate. All the included studies were grouped and summarized according to: type of edentulism (partially edentulous or edentulous), defect type (fenestration, dehiscence, horizontal or vertical defect), and type of augmentation procedure applied. As a result of the former rationale, the results were grouped into partially edentulous patients and edentulous patients, as outlined below and shown in Fig. 1. Partially edentulous patients
(1) Horizontal augmentation group: GBR with simultaneous implant placement; GBR with non-simultaneous implant placement; bone blocks; ridge splitting and expansion. (2) Vertical augmentation group: GBR with simultaneous implant placement; GBR with non-simultaneous implant placement; bone blocks; distraction osteogenesis. Edentulous patients
Horizontal and vertical augmentation groups: GBR with simultaneous implant placement; bone blocks; ridge expansion; distraction osteogenesis; maxillary osteotomies. Statistics
No attempt was made to perform a metaanalysis of the data reported in the papers included in the present review, due to the heterogeneity of the data within a similar
group of clinical situations. In view of the heterogeneity of the data, it was not possible to perform an assessment of the risk of bias within studies. The mean survival and complication rates were calculated by weighted means. Results Partially edentulous patients: horizontal defects
Horizontal bone augmentation may be achieved with different techniques, including GBR, the use of bone blocks, or ridge expansion techniques. To assess if there is a clinical situation that indicates the preferred use of a surgical technique, some data are necessary. Dimensions of the residual ridge at baseline, bone augmentation achieved, and eventually implant outcome must be reported. It was decided to include only studies providing the aforementioned data. GBR and simultaneous implant placement for horizontal augmentation
An initial electronic search identified 938 titles when using the selected key words in terms of GBR techniques for bone augmentation. After final selection based on the abstract and full-text analysis, applying all the inclusion criteria, 15 full-text articles were extracted and included in this systematic review (Table 2). Out of the 15 studies included, four were RCT, one was a CCT, eight were PS, and two were RS. Regarding the type of defect, six papers reported on augmentation of dehiscence and fenestrations, seven on dehiscence only, one on fenestrations only, and one on alveolar ridge defects. In total, 683 patients received 1091 implants simultaneously with GBR augmentation procedures. Five studies reported on the use of resorbable membranes for GBR, five on the use of nonresorbable membranes, and in three studies both resorbable and non-resorbable membranes were used; in one study no membrane was applied within the GBR. One study reported on the use of titanium mesh as a membrane. In this study,15 15 patients were treated with 20 implants. Dehiscences were reconstructed with autograft and covered with titanium mesh as a membrane. Even though mesh should be considered only a space maintaining device and not a barrier membrane, this study has been included in this group. Various bone augmentation materials were used during the GBR procedures. In four of the included studies, the use
Indications for bone augmentation procedures
609
Fig. 1. Flowchart of the study selection process.PE: partially edentulous patients; Ed: edentulous patients; GBR: guided bone regeneration; GBR sim: guided bone regeneration and simultaneous implant placement; GBR non sim: guided bone regeneration and non-simultaneous implant placement; Split crest: ridge splitting/expansion; DO: distraction osteogenesis; Le Fort I: maxillary ridge augmentation and grafting in edentulous patients with Le Fort I osteotomy.
of autogenous bone was reported without the need for a secondary donor site, seven studies described the use of xenografts, one study the use of allograft, and two studies a combination of the various grafting materials. In two studies, no bone augmentation material was used; only the non-resorbable membrane was applied to the defect.16,17 The average preoperative dimension of a dehiscence and fenestration defect within the studies included was: 4.95 mm in horizontal dimension and 5.83 mm in vertical dimension. The average size of a postoperative defect decreased to 1.01 mm in horizontal dimension and 1.36 mm in vertical dimension, with a mean defect fill of 81.9%. Regarding the complications with the procedures used, Dahlin et al. reported an occurrence of flap dehiscences and graft exposure of 13%16 and Zitzmann et al. of 16% when using a resorbable membrane and 24.4% with a non-resorbable membrane,18 while Lorenzoni et al. reported the presence of dehiscence and membrane exposure, but did not define the frequency.17 In one study,19 defects treated with a collagen membrane had 17.4% of exposure, and with an expanded
polytetrafluoroethylene (e-PTFE) membrane, 12.5% of exposure. In a study by Blanco et al., dehiscence occurred in 11.5%.20 In a study by Hammerle and Lang, complications such as infection and necrosis occurred in 20%.21 In the study of De Boever and De Boever, complete defect coverage was found in 13 out of 15 patients (86.6%),22 and in the study by Widmark and Ivanoff, it was observed in 67%.23 Park et al. described dehiscence of the graft or membrane exposure in 24% of the sites.24 In a study by Dahlin et al., exposure was noticed around one implant (2.5%), and another one implant (2.5%) was lost.25 Four studies reported no dehiscence.26–29 The mean complication rate was 4.99%. The average healing time prior to implant loading was 6.8 months. The mean implant survival rate for implants simultaneously placed with the GBR procedure for horizontal augmentation was 92.2%. GBR and non-simultaneous implant placement for horizontal augmentation
Nine hundred and thirty-eight titles were extracted during the initial electronic
search when using the selected key words in terms of GBR techniques for bone augmentation. A refined search narrowed the selection to five full-text articles, which were extracted and included in this systematic review. Five studies met all the inclusion criteria, providing adequate data on preoperative and postoperative defect dimensions (Table 3). Out of the five studies included, one was an RCT, one was a CCT, and three were PS. Defects treated within these studies were described as presenting an initial ridge width that was not sufficient to place a standard-dimension dental implant. In total, 124 patients received 214 implants following the healing period after GBR augmentation procedures. Both resorbable and non-resorbable membranes were used in the analyzed articles. In three publications, a resorbable membrane was used, in one of them a non-resorbable membrane was applied, and one study reported on the use of both resorbable and non-resorbable membranes. Regarding the bone augmentation material applied, in two articles, the use of autogenous bone was reported, one study described the use of xenografts, one study the use of allograft, and one study the
610
Table 2. GBR with simultaneous implant placement for horizontal augmentation. Defect typey
Type of No. of No. of edentulismz patients implants
Site§
Dahlin et al. 199516 Fugazzotto 199726 Zitzmann et al. 199718
CCT Deh/Fen
PMx, PMd
RS
ND
331
626
Max/Mand
25
43
Max/Mand
4
Peleg et al. 199929
PS
Fen
8 EMx, 2 EMd, 12 PE PE
22
44
Max/Mand
5
von Arx and Kurt 199915 Lorenzoni et al. 199917
PS
Deh
PE
15
20
RS
Deh
Single PE, multiple PE, Ed PE
82
2 3
6
7
Deh/Fen
RCT Deh/Fen
Carpio RCT Deh/Fen et al. 200019 Deh/Fen Widmark and PS Ivanoff 200023
45
55
Techniqueô
Max/Mand
GBR
Augmentation (horizontal/ vertical)
Grafting material**
Membraneyy
Preop. dimension (mm)
Postop .dimension Defect (mm) fill (%)
Implant type
Implant placement Healing Follow-up (sim/ period Early Complication Survival Success Loading time non-sim)zz protocol (months) (months) failure rate (%) rate (%) rate (%)
H 1.2 mm
77
Bra˚nemark Sim
ND
4.5
24
3.64
13.00
84.7/93
ND
ND
ND
IMZ
ND
7.5
24
0.64
1.1
98.9
97.6
Measured in mm2 1.1/2.1
92 78
Bra˚nemark Sim
4 Mand 6 Max
5
55–70
2.4
24 16
97.6
ND
Mean 0.25
87
ND
5.6
ND
ND
0
ND
ND
V 6.2
V 0.4
93.5
Melsungen Sim/ Non-sim Sulzer Calcitek Straumann Sim
8.6
6.6
ND
0
5
95
ND
Non-res
V 2/10
ND
ND
Frialit
6
6
18
0
ND
100
ND
H 4.36/3.6, V 4.2/4.4 8.42 exposed threads
H 2.7/1, V 2/2 1.55 exposed threads
54 61 82
Implant Sim Innovations Nobel Sim Biocare
ND
6
ND
6
ND
12.5 17.4 ND
ND
ND
22 16.7 0
ND
ABG
Non-res/ Res None
100
ND
H
Xenograft
Res
Defect size H 0.7/0.66, V 0.6/0.79 H 0, V 2.5
97
Steri-Oss/ Calcitek
Sim
6–8
7
ND
12
None
100
ND
Res
Defect size H 4.3/4.07, V 6.7/6.36 H 0.5, V 3.6
86
Straumann Sim
6–7
6.5
ND
0
20
100
100
ND
2–3
60
1
ND
96.1
96.1
4
4
42
ND
6
94
ND
H
Membrane
Non-res
GBR
H H
Allograft + alloplast Xenograft
Non-res
GBR
GBR
H
ABG
Res
Defect size H 4.6 mm Deh 2–14, Fen 2–12 Measured in mm2 15.8/15.7 Mean 3.67
Max/Mand
GBR
H
ABG
Ti mesh
145
Max/Mand
GBR
H
Membrane
25 23 21
25 23 12
Max/Mand
GBR
H/V
ABG
Max/Mand
GBR
H
21
28
Max/Mand
GBR
Non-res/ Res
Sim
Sim
Nemcovsky et al. 200028
PS
Deh
14 PE single, 3 PE, 4 ED PE
10 Hammerle and Lang 200121 11 Blanco et al. 200520 12 De Boever and De Boever 200522 13 Park et al. 200824 14 Jung et al. 200927 15 Dahlin et al. 201025
PS
Deh
PE
10
10
Max/Mand
GBR
H
Xenograft
PS
Deh/Fen
PE
19
26
Max/Mand
GBR
H
V 3/12
V 0/2
60
PS
Deh
PE (single)
13
16
Max/Mand
GBR
H
ABG/allograft/ Non-res none Xenograft Non-res
V 3/9
V 0/2
97
Bra˚nemark/ Non-sim Straumann Straumann Sim
RCT Deh
PE (single)
22
26
Max/Mand
GBR
H
Allograft
Res
Sim
6
6
12
ND
ND
ND
ND
37
ND
Max/Mand
GBR
V/H
Xenograft
Res
V 1.42, H 1.61 ND
Zimmer
PE
6
6
12
ND
ND
ND
ND
20
40
ND
GBR
V/H
Xenograft
Non-res/ Res
94.9 96.4 67
Straumann Sim
Alv ridge PE defects
V H V V V
83
RCT Deh
Bra˚nemark Sim
7
7
53–72
ND
5
97.5
ND
8
9
PS
6.58, 3.48 5.95, 4.5 3.51
V 2.38
ND, no data; V, vertical; H, horizontal; Preop., preoperative; Postop., postoperative. *
Study type: RCT, randomized controlled clinical trial; CCT, controlled clinical trial; PS, prospective study; RS, retrospective study. Defect type: Deh, dehiscence type defect; Fen, fenestration type defect; Alv ridge defects, alveolar ridge defects. z Type of edentulism: PMx, partially edentulous maxilla; PMd, partially edentulous mandible; EMx, edentulous maxilla; EMd, edentulous mandible; PE, partially edentulous; Ed, edentulous. § Site: Max, maxilla; Mand, mandible. ô Technique: GBR, guided bone regeneration. ** Grafting material: ABG, autogenous bone graft. yy Membrane: Res, resorbable; Non-res, non-resorbable; Ti mesh, titanium mesh. zz Implant placement: Sim, simultaneous; Non-sim, non-simultaneous. y
Milinkovic and Cordaro
Study 1
Study type*
ND ND 0 ND ND 9–10
Bone blocks for horizontal augmentation
ND, no data; V, vertical; H, horizontal; Preop., preoperative; Postop., postoperative; Trans. par., transitional paresthesia. * Study type: RCT, randomized controlled clinical trial; CCT, controlled clinical trial; PS, prospective study. y Type of edentulism: PE, partially edentulous. z Site: Max, maxilla; Mand, mandible. § Technique: GBR, guided bone regeneration. ô Grafting material: ABG, autogenous bone graft; DBBM, deproteinized bovine bone mineral. ** Membrane: Res, resorbable; Non-res, non-resorbable; ePTFE, expanded polytetrafluoroethylene; PGA, polyglycolic acid. yy Implant placement: Non-sim, non-simultaneous. zz RCT/CCT, control group also presented in the table, but not included in the results and evaluation.
Non-sim Straumann Res Xenograft H GBR Max 15 12 H PS 5 Hammerle et al. 200830
H PS
PE
H GBR Max/ Mand 98 51
ND 15
4 Geurs et al. 200834
PE
44 15
PE (anterior max) H RCT 3 Meijndert et al. 200531
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application of a collagen sponge as grafting material. The average preoperative dimension of a ridge width in the included studies was 2.9 mm. The average width of a postoperative ridge increased to 6.2 mm, resulting in a mean linear bone gain of 3.31 mm. When discussing the complication rate, three studies reported no complications during the healing period.30–32 Chiapasco et al. reported membrane exposure in 13.3%.33 Meijndert et al. reported fistulae in two patients and transitory paresthesia in one patient (13.3% and 6.6%, respectively, of the sample),31 while Geurs et al.34 reported fistulae in 6% of the cases, all successfully resolved. The mean complication rate was 11.9%. The average healing time before the implant placement was 7.7 months. The mean implant survival rate for implants non-simultaneously placed with the GBR procedure for horizontal augmentation was 100%. The implant survival rate was not reported in two studies.30,31
4
ND 100 6 0 12 6 ND Non-sim
H width of ND the crest 5.2 crestal, 7.5 apical 3.7 H width of the crest 6.9 Res (PGA)
H width of the crest 2.3 crestal, 4.3 apical H width of the crest 3.2
ND
90.9
96.1 ND 0
Trans. par.
ND 8.5
22.4
3 3
6
Gain Straumann of 2–5 Gain of 2–5 1–3 top of the crest
Non-sim
4 7.5 2.73
1. None 2. Res 3. Res
1. ABG (chin) 2. ABG + membrane 3. DBBM + membrane Allograft
ABG H
Bone blocks GBR
H
ND
93.3 100
100 0
13.3 0
0 12
18–36 6–8
12 9–40
6
Bra˚nemark, Non-sim Straumann Non-sim 2.7
Non-sim Straumann 2.5 H 5.5
7.7 3.17
H3
Non-res (ePTFE) Res
Res
Collagen sponge ABG H
H GBR
GBR
Max/ Mand Max/ Mand Max/ Mand Max 30
27 16
15 PE H CCT
PE H PS
1 Parodi et al., 199832 2 Chiapasco et al. 19993 zz
Grafting materialô Study
Type of No. of No. of Study Defect type* typey edentulismy patients implants
Sitez
Technique§
Augmentation (horizontal/ vertical)
Table 3. GBR with non-simultaneous implant placement for horizontal augmentation.
Membrane**
Preop. dimension (mm)
Linear Postop .dimension bone gain (mm)
Implant type
Implant placement Healing Follow-up (sim/ period Early Complication Survival Success time Loading yy non-sim) protocol (months) (months) failure rate (%) rate (%) rate (%)
Indications for bone augmentation procedures
An initial electronic search resulted in 239 titles when using the selected key words in terms of bone block grafts used for bone augmentation. After the final selection based on abstract analysis, eight full-text articles met all the inclusion criteria and were included in this systematic review (Table 4). Out of the eight studies included, two were RCT, one was a CCT, two were PS, and three were RS. Regarding the inclusion criteria for each study, some authors33–37 described initial horizontal defects numerically, usually as a ridge width less than 4 mm. In the remaining studies, the precise numerical initial defect description was missing, and the initial inclusion criterion was usually a ‘horizontal defect’ or ‘atrophic ridge’. Nevertheless, all included studies reported on precise preoperative ridge dimensions. In summary, 171 patients received 353 implants within a staged approach. The bone augmentation procedure used to correct the horizontally insufficient ridge was the use of bone blocks alone (four studies) or along with additional GBR procedures (four studies). For the additional GBR procedure, five studies reported on the application of autogenous bone chips, while two studies used an allograft, and in one study a xenograft was applied. Four studies reported on the use of resorbable membranes,33,37–39 one on the application of a non-resorbable membrane,35 and in two studies no membrane was used to
612
Table 4. Bone block grafts for horizontal ridge augmentation.
Max/ Bone Mand blocks + GBR Max/ Bone blocks Mand with Ti mesh
H
28
Max/ GBR Mand
H
15
44
Max/ Bone Mand blocks
H
PS
H less than 5
H
PE
40
66
RS
H 2.5–5, H in 5 cases less the 2.5
PE
18
27
PE
15
PE
H/V
3 Chiapasco CCT H
