An In Vivo Study to Compare Location of Neutral Zone Recorded with Two Materials

To establish a relationship between the crest of the alveolar ridge and neutral zone and to compare its location recorded by two different material.

Thirty subjects were selected, and the location of the neutral zone was compared with the mandibular alveolar ridge crest. For each subject neutral zone was recorded by two different recording materials-Low fusing impression compound and tissue conditioner. After neutral zone recording, the relation between mandibular ridge crest and neutral zone location examined radiographically. The data so collected were checked for normality, descriptive statistics and the Mann-Whitney U test was used.

Position of neutral zone was found towards lingual in the posterior, labial side in anterior and almost near to the alveolar ridge crest in premolar region. The thermoplastic flow of the material effects the position of neutral zone but no significant difference was noted in the positions of neutral zone recorded by the two materials in relation to the alveolar ridge crest.

Location of the neutral zone is not affected by the material used in recording it.

The location of the neutral zone varies from subject to subject and mainly depends upon their musculature and can be recorded accurately by using correct technique irrespective of the materials used.