GUY KAZANSKI
5th Course, group 13The effects of smoking on maxillary sinus lift and dental
implant failure: systematic review
Master’s Thesis
Supervisor Ph.D., DDS Povilas Daugela
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AT THE DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY
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LITHUANIAN UNIVERSITY OF HEALTH SCIENCES MEDICAL ACADEMY
FACULTY OF ODONTOLOGY
DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY
The effects of smoking on maxillary sinus lift and dental
implant failure: systematic review
Master’s Thesis
Master’s Thesis The thesis was done
by student ………... supervisor ………... (name-surname, year, group) (degree, name surname)
……….. ……… (signature) (signature)
……… 20…. ……… 20…. (day/month) (day/month)
EVALUATION TABLE OF THE MASTER’S THESIS
OF THE TYPE OF SYSTEMIC REVIEW OF SCIENTIFIC LITERATURE Evaluation: ... Reviewer: ...
(scientific degree. name and surname)
Reviewing date: ...
Compliance with MT
No. MT parts MT evaluation aspects requirements andevaluation
Yes Partially No
1 Is summary informative and in compliance with the 0.3 0.1 0
Summary thesis content and requirements?
2 (0.5 point) Are keywords in compliance with the thesis 0.2 0.1 0
essence?
3 Introduc- Are the novelty, relevance, and significance of thework justified in the introduction of the thesis? 0.4 0.2 0
tion, aim Are the problem, hypothesis, aim, and tasks formed
4 and tasks 0.4 0.2 0
clearly and properly?
(1 point)
5 Are the aim and tasks interrelated? 0.2 0.1 0
6 Selection Is the protocol of systemic review present? 0.6 0.3 0
criteria of Were the eligibility criteria of articles for the
7 the studies, selected protocol determined (e.g., year, language, 0.4 0.2 0
search publication condition, etc.)
methods and Are all the information sources (databases with
8 strategy dates of coverage, contact with study authors to 0.2 0.1 0
(3.4 points) identify additional studies) described and is the last
search day indicated?
Is the electronic search strategy described in such a way that it could be repeated (year of search, the
9 last search day; keywords and their combinations; 0.4 0.1 0
number of found and selected articles according to
the combinations of keywords)?
Is the selection process of studies (screening,
10 eligibility, includedapplicable, included in the meta-analysis)in systemic review or, if 0.4 0.2 0
described?
Is the data extraction method from the articles
11 (types of investigations, participants, interventions, 0.4 0.2 0
analysed factors, indexes) described?
Are all the variables (for which data were sought
12 and any assumptions and simplifications made) 0.4 0.2 0
listed and defined?
Are the methods, which were used to evaluate the
13 risk of bias of individual studies and how this 0.2 0.1 0
information is to be used in data synthesis,
described?
14 Were the principal summary measures (risk ratio,difference in means) stated? 0.4 0.2 0
Is the number of studies screened: included upon
15 assessment for eligibility and excluded upon giving 0.6 0.3 0
the reasons in each stage of exclusion presented? Are the characteristics of studies presented in the
16 Systemiza- included articles, according to which the data wereextracted (e.g., study size, follow-up period, type of 0.6 0.3 0
tion and respondents) presented?
analysis of
Are the evaluations of beneficial or harmful
data outcomes for each study presented? (a) simple
17 (2.2 points) summary data for each intervention group; b) effect 0.4 0.2 0
estimates and confidence intervals)
Are the extracted and systemized data from studies
18 presented in the tables according to individual 0.6 0.3 0
tasks?
19 Arerelevance indicated?the main findings summarized and is their 0.4 0.2 0
20 Discussion Are the limitations of the performed systemic 0.4 0.2 0
(1.4 points) review discussed?
21 Doesresults?author present the interpretation of the 0.4 0.2 0
22 Do the conclusions reflect the topic, aim, and tasks 0.2 0.1 0
Conclusions of the Master’s thesis?
23 (0.5 points) Are the conclusions based on the analysed material? 0.2 0.1 0
24 Are the conclusions clear and laconic? 0.1 0.1 0
25 Is the references list formed according to the 0.4 0.2 0
requirements?
Are the links of the references to the text correct?
26 Are the literature sources cited correctly and 0.2 0.1 0
References precisely?
27 (1 point) Is the scientific levelMaster’s thesis? of references suitable for 0.2 0.1 0
Do the cited sources not older than 10 years old
28 form at least 70% of sources, and the not older than 0.2 0.1 0
5 years – at least 40%?
Additional sections, which may increase the collected number of points
29 Annexes Do the presented annexes help to understand the +0.2 +0.1 0
analysed topic?
Practical Are the practical recommendations suggested and
30 recommen- are they related to the received results? +0.4 +0.2 0
dations
Were additional methods of data analysis and their
31 results used and described (sensitivity analyses, +1 +0.5 0
meta-regression)?
*Remark: the amount of collected points may exceed 10 points. Reviewer’s comments: ___________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ___________________________
Reviewer’s name and surname Reviewer’s signature
Was meta-analysis applied? Are the selected
32 statistical methods indicated? Are the results of +2 +1 0
each meta-analysis presented?
General requirements, non-compliance with which reduce the numberof points
33 Is the thesis volume sufficient (excluding 15-20 pages <15 pages
annexes)?
(-2 points) (-5 points)
34 Is the thesis volume increasedartificially? -2 points -1 point
35 Does the thesis structure satisfy therequirements of the Master’s thesis? -1 point -2 points
36 Is the thesis written in correct language,scientifically, logically and laconically? -0.5 point -1 points
37 Are there any grammatical, style orcomputer literacy-related mistakes? -2 points -1 points
38 Is text consistent, integral, and are thevolumes of its structural parts balanced? -0.2 point -0.5 points
General
39 Amount of plagiarism in the thesis. >20%
require-
(not evaluated)
ments Is the content (names of sections and sub-
40 sections and enumeration of pages) incompliance with the thesis structure and -0.2 point -0.5 points
aims?
Are the names of the thesis parts in
41 compliance with the text? Are the titles ofsections and sub-sections distinguished -0.2 point -0.5 points
logically and correctly?
42 Are there explanations of the key termsand abbreviations (if needed)? -0.2 point -0.5 points
Is the quality of the thesis typography
43 (quality of printing, visual aids, binding) -0.2 point -0.5 points
good?
*In total (maximum 10 points):
TABLE OF CONTENTS
1. SUMMARY ... 8
2. INTRODUCTION... 9
3. MATERIAL AND METHODS ... 11
4. RESULTS ... 14
5. SYSTEMIZATION AND ANALYSIS OF DATA ... 17
6. DISCUSSION ... 21
7. ACKNOWLEDGMENTS AND DISCLOSURE STATEMENTS... 23
8. CONCLUSIONS ... 24
9. PRACTICAL RECOMMENDATIONS ... 24
10. REFERENCES ... 25
8 THE EFFECTS OF SMOKING ON MAXILLARY SINUS LIFT AND DENTAL IMPLANT
FAILURE: SYSTEMATIC REVIEW
1. SUMMARY
Introduction:
The purpose of this review is to evaluate the impact of tobacco smoking on the rate of dental implants failures in grafted maxillary sinuses.
Materials and methods:
PubMed/Medline and Cochrane Library databases were electronically searched to collect information and articles on smoker and non-smoker patients who underwent maxillary sinus lift surgeries. The search was based on PRISMA statement and was limited to English language articles, published between 1999 – 2020.
Results:
In total, 78 articles were reviewed, six retrospective and prospective articles met the inclusion criteria and were included in the final data synthesis. 630 patients participated in the included studies with 1458 implants that were placed in non-smoker patients and 730 implants placed in smokers patients in the augmented maxillary sinuses. In this literature review, 4 out of 6 studies have shown a higher implant failure rate amongst smokers as opposed to non-smokers.
Conclusion:
Within the limitations of this systematic review, tobacco smoking appealed to induce a higher rate of dental implant failure in grafted maxillary sinuses.
9
2. INTRODUCTION
The maxillary sinus is the largest of the paranasal sinuses, and it has a pyramidal shape cavity [1]. Its function is to reduce skull weight, produce mucus, and affect the tone quality of voice [2]. The maxillary sinus is covered by a thin mucous membrane (i.e., Schneiderian membrane), which consists of an overlaid periosteum with a thin layer of pseudostratified ciliated columnar epithelium [3,4]. The maxillary sinus structure comprises six borders. In which the lateral wall is forming the buccal aspect of the sinus and contributes to the posterior maxillary and zygomatic process. This wall provides access for the lateral wall sinus graft procedure [1].
The sinus floor is formed by the alveolar and palatine processes of the maxilla and lies below the nasal cavity, which is usually extending from the mesial part of the first premolar to the distal portion of the third molar with the lowest at the first and second molar. The floor of the sinus is separated from molar dentition by a different layer of alveolar bone [5].
The maxillary sinus pneumatizes over time, thus causing the sinus volume to increase with age, resulting in over expansion of the sinus cavity. The bone that is lost subsequently to this cavity expansion is the maxillary alveolar bone, which supports the teeth [4]. This maxillary alveolar bone is comprising a potential ground for implants in the posterior maxillary region.
Maxillary sinus floor augmentation aimed to overcome the bone loss and it was first reported by Boyne in the 1960s [6].Maxillary sinus lift procedures have proved to be a preferable procedure to restore the lack of bone in the posterior part of the maxillary region. Several techniques and few bio-materials have proven effective in achieving acceptable clinical outcomes [7]. Multiple evidence-based reviews have shown that sinus floor augmentation results in an overall implant survival rate of more than 90% [6,8]. Dental implants failures still occur in patients receiving dental implantation, and it has been associated with poor oral hygiene, certain systemic diseases, and/or bad habits, particularly tobacco smoking [9].
Tobacco smoking is one of the most important and rather modifiable or preventable public health threats worldwide with devastating multisystem effects and carcinogenesis [10]. Tobacco smoke contains more than 4000 potentially toxic substances, including the notorious substance nicotine. It has a series of direct and indirect systemic and local effects on bone metabolism [11] and strongly suggested that local exposure of the peri-implant tissues to tobacco products may be an essential factor leading to an overall increase in implant failure rate in smokers [12]. A recent meta-analysis on the subject observed that smoking was associated with a higher risk of dental implant failure [13].
10 Task: To compare the implant failure rate in grafted maxillary sinuses between smokers and non-smokers by the means of systematic literature review.
11
3. MATERIAL AND METHODS
Bioethics approval code -BEC-OF-148
Focus question
The focus question was developed according to the problem, intervention, comparison, and outcome (PICO) are presented in Table 1.
Table 1. PICO table
Population (P) Partial or fully edentulous patients, that undergo maxillary sinus lift surgeries and dental implant placement in the posterior part of the maxilla. Intervention (I) Dental implant placement in the area of the maxillary sinus in smoking
patients
Comparison (C) Dental implant placement in the area of the maxillary sinus in non-smoking patients
Outcome (O) Implant failure in both smokers and non-smokers patients after maxillary sinus floor augmentation surgery
Focus question "Does tobacco smoking have a negative influence on the survival rate of dental implants placed in grafted maxillary sinuses?"
Types of publications
-Publications are written in the English language, published between 1999-2020. -Studies performed on humans only.
Types of studies
12
Population
Smoker and non-smoker patients, who underwent a maxillary sinus lift procedure and dental implantation.
Data collection
The articles and information collected from PubMed/Medline and Cochrane Library databases and a manual search in free access to dental journals.
Literature search and screening
Protocol
To identify the relevant studies, a detailed electronic search was carried out according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [14].
The search involved PubMed/Medline and Cochrane Library databases using different combinations of the following keywords: [“Dental Implant “OR“ Implant failure“] AND [“sinus lift” OR “sinus grafting” OR “sinus augmentation” OR “sinus floor elevation] AND [“tobacco” OR “smoking” OR “nicotine] AND [“maxillary sinus” OR “maxilla”].
Selection of studies
Articles were searched clarified according to inclusion and exclusion criteria.
Inclusion criteria were the following:
- Publications are written in the English language. - Studies performed on humans only.
- Investigated outcomes of maxillary sinus lift surgeries and dental implant failures in smoking and non-smoking patients.
- Studies published from September 1999 to June 2020.
13
Exclusion criteria were the following: - Publications in languages other than English. - Case reports, systematic reviews, Meta-Analyses. - Not relevant data on the selected topic.
- Studies performed on animals.
Titles and abstracts were first obtained for all the studies that were considered adequate for inclusion in this systematic review. (Figure 1)
Data items:
"Authors" and "Year of publication" - revealed the author and the publication year. "Type of articles" - describes the design of the study.
"Participants" - present the number of the people in each study, the followed-up period, and the number of implants placed in the grafted maxillary sinus.
"Outcome measures " - describes the status of the implant lost/failure.
"Results non-smokers" - shows the number of implants was placed in non-smoker patients and the number of failed implants.
"Results smokers" - indicates the number of implants was placed in smoker patients and the number of failed implants.
"Conclusions" - a short conclusion of each study.
Methodological quality of studies (risk of bias)
14
4. RESULTS
15
Figure 1. PRISMA flow diagram
•PubMed/Medline, Cochrane Library database advanced search •Search keywords: “maxillary sinus“,”smoking”,”dental implant” •Language: English
(n=77)
Records after duplicates removed (n=73) (n = 400 ) Identificati on Screening Eligibility Included Full-text articles assessed for eligibility
(n=15) Records screened (n=73)
Filtered
Records excluded (n=58) not relevant titles and abstractsFiltered
Remove of duplication (n=5) Studies included in qualitative synthesis (n=6)Additional records identified through other sources
Journal of Oral Science & Rehabilitation 2015 (n=1)
Full-text articles excluded, with reasons (n=9)
•Not relevant results (n=6) •Review or Meta-Analysis (n=3)
16
Quality of bias assessment
The risk of bias that done overall studies in this review appears and is arranged in Table 2.
According to the Newcastle-Ottawa Quality Assessment Tool for Cohort Studies [15], three studies were evaluated with score 8 [18,19,20]; two studies were evaluated with score 7 [16,21] and one study with score 6 [17].
Table 2. Risk of bias assessment.
Studies
Selection
Comparability Outcome Total score
Kan et al. (1999) [16]
★★★★
★
★★
7Cho-Lee et al. (2010) [17]
★★
★
★★★
6Mordenfled et al. (2014) [18]
★★★★
★
★★★
8Hyun-Suk Cha et al. (2014) [19]
★★★★
★
★★★
8Calatayud et al. (2015) [20]
★★★★
★
★★★
817
5. SYSTEMIZATION AND ANALYSIS OF DATA
.
Table 3. Data analysis of included studies.
Authors and publication
year
Type of articles Participants Outcome
measures
Results non-smokers
Results smokers Conclusions
Kan et al. (1999) [16] Retrospective design, 0 to 60 months follow-up (mean post prosthetic time 41.6 months) 60 patients - 228 implants were evaluated, 205 remained in function Implant loss/failure Implants placed in non-smokers = 158. 11 implants lost non-smokers (7.0%)
Implants placed in smokers = 70. 12 implants lost smokers (17.1%).
Patients with a smoking history and bad oral hygiene were related to getting higher failure rates. There were lower implant survival rates in
smokers (82,9%) than non-smokers (93%) group after a mean
postprosthetic follow-up time of 41.6 months. Cho-Lee et al. (2010) [17] Retrospective design, mean duration 60.7 months 119 patient, 272 implants were placed within the grafted bone
Implant loss/failure Implants placed in non-smokers = 192 9 implants lost in non-smokers (4.8%) Implants placed in smokers = 80. 8 implants lost in smokers (10.0%)
The overall survival rate was high (93%). There were no significant differences (p=0.114) in the implant survival rates in the smoker group (90%) and non-smoker group (95.2%). Mordenfled et al. (2014) [18] Prospective study 10 years’ follow-up 20 patients, 79 of 108 implants placed in the sinus site. Six patients did not complete the entire study period
Implant loss/failure Implants placed in non-smokers = 50 4 implants lost in non-smokers (8.0%) Implants placed in smokers = 29. 5 implants lost in smokers (17.2%)
The implant survival rate in the smokers group was 82.8% and in the non-smokers group was 92%. It were
statistically significant differences. for
smoking patients (p < 0.001) and for
non-smoking patients was not
18 Hyun-Suk Cha et al. (2014) [19] Prospective study follow-up of 57.1 ±15.6 (36–98) months 161 patients, 562 implants
18 smoking patients and 143 nonsmoking patients Implant loss/failure implants placed in nonsmokers = 414. 9 implants lost in non-smokers (2.17%) Implants placed in smokers = 48. 7 implants lost in smokers (14.58%)
The implant survival rate between the smokers and non-smokes was
significantly different (p=0.0003). A possible factor for implant failure was smoking habit.
Calatayud et al. (2015) [20] Retrospective clinical study, follow-up 12 months after loading 46 patients, 102 implants, 69 implants were placed in nonsmokers and 33 in smokers Implant loss/failure Implants placed in nonsmokers = 69 4 implants lost in non-smokers (5.8%) Implants placed in smokers = 33 3 implants lost in smokers (9.1%)
The present study shows that smoking and poor oral hygiene may negatively influence the outcome of implants placed both in stages of indirect and direct sinus lift procedures (one stage-two stages). The smokers group showed a lower implant survival rate (90.9%) at 12 months than non-smokers (94.2%), but these were not statistically significant differences (p > 0.05). Zinser et al. (2013) [21] Retrospective study, 14 years follow-up 224 patients who received 1045 implants, 470 implants were placed in smokers and 575 implants placed in non-smokers Implant loss/failure Implants placed in non-smokers = 575 23 implants lost in non-smokers (4%) Implants placed in smokers = 470 47 implants lost in smokers (10%)
This study showed an average survival rate of 93.3% and examined the predictors of implant failure following maxillary sinus floor augmentation. The results show that the lateral maxillary sinus augmentation is an effective and predictable technique but that there are risk factors associated. smoking, residual bone height, and age are essential, type of graft material. The
smoker's group presented an
approximately two times greater
19
Individualization of results from each study
In the research conducted by Kan et al. [16] in 1999 of sixty patients, 228 implants were placed in grafted maxillary sinuses when 205 remained in place after a mean follow-up period of 41.6 months. In the smokers group, 12 of 70 implants (17.1%) were lost, in the non-smokers group 11 of 158 implants (7.0%) classified as failures. There were significant differences in the
accumulative implant success rates between smokers (65.3%) and nonsmokers (82.7%) (p=0.027). In a study by Cho-Lee et al. [17] of 119 patients, 272 implants were placed in grafted maxillary sinuses. The mean follow-up duration was 60.7 months. In the smokers group, 8 implants of 80 (10%) were lost, and in non-smokers group, 9 of 192 implants (4.8%) were lost, respectively. There were no significant differences (p=0.114) in the implant survival rates in the smokers group (90%) and non-smokers group (95.2%).
In the study performed by Mordenfed et al., 20 patients were included in the research, when only 14 followed throughout this study, six patients that didn’t finish the research included in the data analysis. Of 108 implants, only 79 implants placed in the grafted maxillary sinus. 9 smokers had 29 implants, and 11 non-smokers had 50 implants. In the smokers group, 5 implants (17.2%) were lost, and in the non-smokers group, 4 implants (8.0%) were lost. The differences in the implant survival rate in the smokers group was (82.8%) and in the non-smokers group was (92%).It were statistically significant differences for smoking patients (p < 0.001) and for non-smoking patients was not statistically significant (p = 0.871).
In 2014 Hyun-Suk Cha et al. conducted a retrospective study of 161 patients, 18 patients were smokers, and 143patients were non-smokers. The mean follow-up period was 57.1 ± 15.6 months. In the smokers group, 7 of 48 implants (14.58%) were lost, and in the non-smoker group, 9 of 414 implants(2.17%) implants were lost in grafted maxillary sinuses. The implant survival rate between the smokers and non-smokes was statistically significantly different (p=0.0003).
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6. DISCUSSION
The purpose of this systematic review is to examine the effect that tobacco smoking has on dental implants in the grafted maxillary sinuses and its relevance to the failures of such implants. This is performed by comparing the displayed implant results across studies conducted on sample groups of smokers and sample groups of non-smokers. The goal of this study was to confirm the claim that smoking is indeed an influential factor when it comes to procedures like implantation in the area of the maxillary sinus and the outcomes of it on dental implants.The negative impact of smoking on implant survival in maxillary sinus augmentation was verified as 4 out of 6 studies of this systematic review have shown a higher implant failure rate amongst smokers as opposed to non-smokers. However, 2 of the six studies included in this review might call for a slightly different approach, as these studies did not find that smoking tobacco act as a key factor, causing statistically significant differences in the rates of implant failure[17,18].
According to Kan et al., the direct assumption that there is a correlation between smoking tobacco and implant failures may be accurate [16], further validating other evidence-based studies have shown that implants in the grafted maxillary sinus normally have a 90% survival rate [8].
In all studies included, the percentage of failed implants amongst smokers was higher than the percentage of failed implants in non-smokers. However, the studies show a difference in the way they were conducted and the number of patients they were conducted. Each study, whether prospective or retrospective, showed a significant difference in the follow-up time of the study. Additionally, each study was conducted on different sample sizes, and the number of implants placed in patients varied accordingly. These are great examples of the likely limitations that the heterogenicity of the studies brings, making it difficult to confirm that smoking tobacco has a direct impact on the failure of implants in the grafted maxillary sinus.
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7. ACKNOWLEDGMENTS AND DISCLOSURE STATEMENTS
24
8. CONCLUSIONS
Within the limitations of this systematic review the role of tobacco smoking may be further supported as a risk factor for adverse outcomes of oral procedures and increment of dental implant failures in the grafted maxillary sinuses.
9. PRACTICAL RECOMMENDATIONS
25
10. REFERENCES
1. Bathla SC, Fry RR, Majumdar K. Maxillary sinus augmentation. J Indian Soc Periodontol 2018;22:468-73.
2. Parks ET. Cone-beam computed tomography for the nasal cavity and paranasal sinuses. Dent Clin North Am 2014;58(3):627–51. from: http://dx.doi.org/10.1016/j.cden.2014.04.003. 3. Lin YH, Yang YC, Wen SC, Wang HL. The influence of sinus membrane thickness upon
membrane perforation during lateral window sinus augmentation. Clin Oral Implants Res. 2016;27(5):612–7.
4. Carrao V, DeMatteis I. Maxillary Sinus Bone Augmentation Techniques. Oral Maxillofac Surg Clin North Am. 2015;27(2):245–53.
5. Iwanaga J, Wilson C, Lachkar S, Tomaszewski KA, Walocha JA, Tubbs RS. Clinical anatomy of the maxillary sinus: Application to sinus floor augmentation. Anat Cell Biol. 2019;52(1):17– 24.
6. Pjetursson BE, Tan WC, Zwahlen M, Lang NP. A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation: Part I: Lateral approach. J Clin Periodontol. 2008;35(SUPPL. 8):216–40.
7. Galindo-Moreno P, Fernández-Jiménez A, O’Valle F, Silvestre FJ, Sánchez-Fernández E, Monje A, et al. Marginal bone loss in implants placed in grafted maxillary sinus. Vol. 17, Clinical Implant Dentistry and Related Research. 2015. 373–383.
8. Del Fabbro M, Wallace S, Testori T. Long-Term Implant Survival in the Grafted Maxillary Sinus: A Systematic Review. Int J Periodontics Restorative Dent. 2013;33(6):773–83.
9. Sun C, Zhao J, Jianghao C, Hong T. Effect of heavy smoking on dental implants placed in male patients posterior mandibles: A prospective clinical study. J Oral Implantol. 2016;42(6):477–83.
10. Chowdhury S, Chakraborty P pratim. Universal health coverage ‑ There is more to it than meets the eye. J Fam Med Prim Care [Internet]. 2017;6(2):169–70.
11. Chrcanovic BR, Albrektsson T, Wennerberg A. Smoking and dental implants: A systematic review and meta-analysis. J Dent [Internet]. 2015;43(5):487–98. Available from: http://dx.doi.org/10.1016/j.jdent.2015.03.003
12. Johnson GK, Guthmiller JM. The impact of cigarette smoking on periodontal disease and treatment. Periodontol 2000. 2007;44(1):178–94.
13. Chen H, Liu N, Xu X, Qu X, Lu E. Smoking, Radiotherapy, Diabetes and Osteoporosis as Risk Factors for Dental Implant Failure: A Meta-Analysis. PLoS One. 2013;8(8).
26 items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med. 2009;6(7).
15. Wells GA, Shea B, O'Connell D, Peterson J, Welch V, Losos M, Tugwell P. The Newcastle-Ottawa scale (NOS) for assessing the quality of nonrandomized studies in meta-analyses. [URL:http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp]
16. Kan JY, Rungcharassaeng K, Lozada JL, Goodacre CJ. Effects of smoking on implant success in grafted maxillary sinuses. J Prosthet Dent. 1999;82(3):307–11.
17. Cho-Lee G-Y, Naval-Gias L, Castrejon-Castrejon S, Capote-Moreno AL, Gonzalez-Garcia R, Sastre-Perez J, et al. A 12-year retrospective analytic study of the implant survival rate in 177 consecutive maxillary sinus augmentation procedures. Int J Oral Maxillofac Implants. 2010;25(5):1019–27. from: http://www.ncbi.nlm.nih.gov/pubmed/20862418
18. Mordenfeld A, Albrektsson T, Hallman M. A 10-Year Clinical and Radiographic Study of Implants Placed after Maxillary Sinus Floor Augmentation with an 80:20 Mixture of Deproteinized Bovine Bone and Autogenous Bone. Clin Implant Dent Relat Res. 2014;16(3):435–46.
19. Cha HS, Kim A, Nowzari H, Chang HS, Ahn KM. Simultaneous Sinus Lift and Implant Installation: Prospective Study of Consecutive Two Hundred Seventeen Sinus Lift and Four Hundred Sixty-Two Implants. Clin Implant Dent Relat Res. 2014;16(3):337–47.
20. Calatayud LM, Millán JR, Oltra DP, Diago MP, Mira BG, Diago & MP. Influence of smoking and oral hygiene. J Sci Rehabil. 2015;1(1).
21. Zinser MJ, Randelzhofer P, Kuiper L, Zöller JE, De Lange GL. The predictors of implant failure after maxillary sinus floor augmentation and reconstruction: A retrospective study of 1045 consecutive implants. Oral Surg Oral Med Oral Pathol Oral Radiol [Internet]. 2013;115(5):571–82. Available from: http://dx.doi.org/10.1016/j.oooo.2012.06.015
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11. ANNEXES
Newcastle-Ottawa Quality Assessment Form for Cohort
Studies
Note: A study can be given a maximum of one star for each numbered item within the Selection and Outcome categories. A maximum of two stars can be given for Comparability.
Selection
1) Representativeness of the exposed cohort a) Truly representative (one star)
b) Somewhat representative (one star) c) Selected group
d) No description of the derivation of the cohort 2) Selection of the non-exposed cohort
a) Drawn from the same community as the exposed cohort (one star) b) Drawn from a different source
c) No description of the derivation of the non exposed cohort 3) Ascertainment of exposure
a) Secure record (e.g., surgical record) (one star) b) Structured interview (one star)
c) Written self-report d) No description e) Other
4) Demonstration that the outcome of interest was not present at the start of the study a) Yes (one star)
b) No
Comparability
1) Comparability of cohorts on the basis of the design or analysis controlled for confounders a) The study controls for age, sex and marital status (one star)
b) Study controls for other factors (list) _________________________________ (one star) c) Cohorts are not comparable on the basis of the design or analysis controlled for confounders Outcome
1) Assessment of outcome
a) Independent blind assessment (one star) b) Record linkage (one star)
c) Self report d) No description e) Other
28
a) Yes (one star) b) No
Indicate the median duration of follow-up and a brief rationale for the assessment above:____________________ 3) Adequacy of follow-up of cohorts
a) Complete follow up- all subject accounted for (one star)
b) Subjects lost to follow up unlikely to introduce bias- number lost less than or equal to 20% or description of those lost suggested no different from those followed. (one star)
c) Follow up rate less than 80% and no description of those lost d) No statement
E-18
Thresholds for converting the Newcastle-Ottawa scales to AHRQ standards (good, fair, and poor):
Good quality: 3 or 4 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3
stars in outcome/exposure domain
Fair quality: 2 stars in selection domain AND 1 or 2 stars in comparability domain AND 2 or 3 stars in
outcome/exposure domain
Poor quality: 0 or 1 star in selection domain OR 0 stars in comparability domain OR 0 or 1 stars in
