Operative dentistry aje qualtrough, jd satterthwaite la morrow, pa brunton

Controlled vocabulary and free text-terms
Many people when searching electronic databases tend to rely on
free-text searching; simply typing a phrase, such as ‘ceramic inlays’,
into the search box. The problem that arises when relying on free-text
searching is that it depends on finding the exact match of text within
the title, abstract (if present) or indexing field of the record. If the
author of a study has described the restoration in any way other than
‘ceramic inlays’, for example ‘porcelain inlays’, the record will not be
retrieved. To help overcome this, many databases use an indexing
system for coding records entered onto the database. For example,
MEDLINE and The Cochrane Library both use MeSH (Medical Subject
Headings). All references added onto the database are assigned
appropriate MeSH by indexers at the NLM. An example of some 
dental MeSH terms (section of MeSH Tree) are shown below. The
broadest term ‘Dentistry, operative’ at the top and more specific 
headings indented below:
• Dentistry, operative
• Crown lengthening
• Dental cavity lining
• Dental restoration failure
• Dental restoration, permanent
—
Crowns
°
Post and core technique
—
Inlays
—
Marginal adaptation (dentistry)
• Dental restoration, temporary
—
Crowns
°
Post and core technique
It is recommended that a combination of appropriate MeSH and free-
text terms be used when searching electronic databases to improve
the identification of all relevant research articles.
Search operators and truncation symbols
Most databases allow the combining of search terms using the
Boolean operators AND, OR and NOT. The operator AND is used
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when the research article must contain both search terms, for example
‘ceramic’ AND ‘inlay’ (this will reduce the number of articles
retrieved). The operator OR is used when either search term is accept-
able, for example ‘porcelain’ OR ‘ceramic’ (this will broaden the 
number of articles retrieved). By using NOT between search terms
will require the article to contain the first search term but not 
the second, for example ‘restoration’ NOT ‘crown’. In addition, 
some databases use proximity operators such as NEAR, NEXT or
ADJACENT, which can also be helpful in focusing a search.
Truncation symbols can be used to broaden a search by allowing
any ending to a given free-text word. For example, the truncation
symbol in The Cochrane Library and PubMed is an asterisk. If placed at
the end of ‘restorat*’ this will allow the retrieval of records containing
the words restorative, restoration, restorations, restorating, etc. . . .
Truncation symbols vary according to databases. When choosing to
search a particular database, ensure you are familiar with both the
search operators and the truncation symbols available.
If we return to the ceramic inlays example, and acknowledge that
the most appropriate database to search initially would be The
Cochrane Library, we can explore how search results can vary depend-
ing upon the approach we take. Table 8.3 shows the results obtained
when different free-text terms, MeSH terms, search operators and
truncation symbols are used.
The results obtained through searching The Cochrane Library
(Table 8.3) identified one relevant systematic review, entitled 
‘Ceramic inlays for restoring posterior teeth’
3
. As systematic reviews
provide a comprehensive, objective overview of research in a given
area, this would be the obvious article to read first. If such a systematic
review did not exist, individual studies of an appropriate study
design (in this case RCTs) would have to be examined.