Orthodontic Treatment With Fixed Appliances and Enamel Color
Orthodontic Treatment With Fixed Appliances and Enamel Color
This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the Cochrane Handbook. A review protocol does not exist.
The databases Medline (1950 to 6 July 2014), EMBASE via OVID (1980 to 6 July 2014), Web of Science (1950 to 6 July 2014), Google Scholar, and CENTRAL (The Cochrane Library, 2014, Issue 7) were searched. For the identification of studies considered for inclusion in this review, we developed detailed search strategies for each database searched. These were based on the search strategy developed for MEDLINE (see Table 1), but revised appropriately for each database to take into account differences in controlled vocabulary and syntax rules. This search strategy was used in addition to the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying randomized trials in MEDLINE: sensitivity maximising version (2008 revision), as referenced in Chapter 6.4.11.1 and detailed in box 6.4.c of the Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated in March 2011).
We also manually searched relevant orthodontics journals (American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, Angle Orthodontist, Journal of Orthodontics, and World Journal of Orthodontics). We checked the bibliographies of included publications and relevant review articles for studies not identified by the above search strategies. We contacted the authors of studies designated for inclusion, to identify unpublished or ongoing trials.
For inclusion, studies were required to meet the following criteria:
Types of Studies. We included randomized controlled trials (RCTs), and prospective controlled clinical studies.
Participants. We included participants with fixed orthodontic appliances. We excluded participants who had had previous active orthodontic treatment, or had a relevant medical history.
Interventions. Assessments of the influence of the type of orthodontic adhesive system on enamel color changes during bonding and after debonding. Effects of clean-up procedures on the enamel surface were also evaluated.
Outcome Measures. Color changes before and after orthodontic treatment.
Studies other than RCTs or prospective controlled studies, studies that did not investigate enamel color changes or did not investigate fixed appliance interventions, and animal studies were excluded during the screening process. At least two authors independently assessed the list of titles and abstracts of potentially eligible studies. We obtained full-text versions of publications that fulfilled the inclusion criteria. Any disagreements were resolved by discussion or judged by a third reviewer.
At least two authors assessed all included studies, to confirm eligibility, assess risk of bias, and extract data. The following data were extracted: Study design, participants, intervention, outcome measure. The risks of bias associated with each included study were independently assessed by two authors using the Cochrane risk of bias assessment tool. The potential sources of bias considered were sequence generation, allocation concealment, blinding of outcome and participants, completeness of outcome data, risk of selective outcome reporting, and risk of other potential sources of bias. Each of these domains included one or more specific entries in a "Risk of bias" table. Within each entry, what was reported in the study was described and a judgment relating to the risk of bias for that entry was assigned. Where the methodology of the study was clearly reported, a judgment of "Low risk" of bias or "High risk" of bias was made. Where trial methodology was unclear, the domain was assigned a determination of "Unclear risk" of bias, unless further information was available. After taking into account the additional information provided by the authors of the trials, we grouped studies into three categories (Table 2).
We only conducted a meta-analysis of data from similar studies reporting the same outcome measures. We combined risk ratios for dichotomous data, and mean differences for continuous data, using random-effects models provided there were more than three studies in the meta-analysis. The I statistic was to be used to quantify heterogeneity, where I > 50% was considered substantial heterogeneity.
Methods
This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the Cochrane Handbook. A review protocol does not exist.
Search Methods for Identification of Studies
The databases Medline (1950 to 6 July 2014), EMBASE via OVID (1980 to 6 July 2014), Web of Science (1950 to 6 July 2014), Google Scholar, and CENTRAL (The Cochrane Library, 2014, Issue 7) were searched. For the identification of studies considered for inclusion in this review, we developed detailed search strategies for each database searched. These were based on the search strategy developed for MEDLINE (see Table 1), but revised appropriately for each database to take into account differences in controlled vocabulary and syntax rules. This search strategy was used in addition to the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying randomized trials in MEDLINE: sensitivity maximising version (2008 revision), as referenced in Chapter 6.4.11.1 and detailed in box 6.4.c of the Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated in March 2011).
We also manually searched relevant orthodontics journals (American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, Angle Orthodontist, Journal of Orthodontics, and World Journal of Orthodontics). We checked the bibliographies of included publications and relevant review articles for studies not identified by the above search strategies. We contacted the authors of studies designated for inclusion, to identify unpublished or ongoing trials.
Selection of Studies
For inclusion, studies were required to meet the following criteria:
Types of Studies. We included randomized controlled trials (RCTs), and prospective controlled clinical studies.
Participants. We included participants with fixed orthodontic appliances. We excluded participants who had had previous active orthodontic treatment, or had a relevant medical history.
Interventions. Assessments of the influence of the type of orthodontic adhesive system on enamel color changes during bonding and after debonding. Effects of clean-up procedures on the enamel surface were also evaluated.
Outcome Measures. Color changes before and after orthodontic treatment.
Studies other than RCTs or prospective controlled studies, studies that did not investigate enamel color changes or did not investigate fixed appliance interventions, and animal studies were excluded during the screening process. At least two authors independently assessed the list of titles and abstracts of potentially eligible studies. We obtained full-text versions of publications that fulfilled the inclusion criteria. Any disagreements were resolved by discussion or judged by a third reviewer.
Data Extraction and Analysis
At least two authors assessed all included studies, to confirm eligibility, assess risk of bias, and extract data. The following data were extracted: Study design, participants, intervention, outcome measure. The risks of bias associated with each included study were independently assessed by two authors using the Cochrane risk of bias assessment tool. The potential sources of bias considered were sequence generation, allocation concealment, blinding of outcome and participants, completeness of outcome data, risk of selective outcome reporting, and risk of other potential sources of bias. Each of these domains included one or more specific entries in a "Risk of bias" table. Within each entry, what was reported in the study was described and a judgment relating to the risk of bias for that entry was assigned. Where the methodology of the study was clearly reported, a judgment of "Low risk" of bias or "High risk" of bias was made. Where trial methodology was unclear, the domain was assigned a determination of "Unclear risk" of bias, unless further information was available. After taking into account the additional information provided by the authors of the trials, we grouped studies into three categories (Table 2).
We only conducted a meta-analysis of data from similar studies reporting the same outcome measures. We combined risk ratios for dichotomous data, and mean differences for continuous data, using random-effects models provided there were more than three studies in the meta-analysis. The I statistic was to be used to quantify heterogeneity, where I > 50% was considered substantial heterogeneity.
