A Clinical Comparative Study of Two Different Materials Used in Recording Neutral Zone in Completely Edentulous Patients at Jaipur Dental College, Jaipur.

Stability of mandibular dentures in highly resorbed ridges is a great challenge and one of the deciding factors in the failure or success of the complete denture. The neutral zone technique is an alternative approach for the construction of complete dentures with such kind of challenges. The objective of this research was to study the accuracy of reproducibility of Neutral Zone by two commonly available dental materials, tissue conditioner and zinc oxide eugenol paste.METHODSViscogel tissue conditioner and zinc oxide eugenol paste are easy flowing recording materials and can be recorded by using support. Hence to study the accuracy of the reproducibility of the neutral zone, specially designed acrylic rims with occlusal stops were used which supported the recording materials adequately in the posterior region of the inter ridge space. Swallowing method was used to record the neutral zone, five times by each material. Bucco-lingual dimension of the neutral zone was recorded at predetermined reference points for all individuals with the help of a micrometer. 40 patients were selected with Class 1 jaw relations.RESULTSIn this in vivo study done in selected 40 patients, selection done according to selection criteria to compare the accuracy of reproducibility of Neutral Zone by tissue conditioner [Dentsply, Visco-gel, Temporary Soft Denture Liner]and zinc oxide eugenol impression paste [DPI Impression Paste R]. Neutral zone were recorded in all the cases with both materials and data recorded to create the results. By summarizing the results as width (in mm.) of the neutral zone at point 1, 2, 3, and 4 for tissue conditioner [Dentsply, Visco-gel, and Temporary Soft Denture Liner] were 10.36, 10.06, 10.51 and 10.21 respectively. For zinc oxide eugenol impression paste [DPI Impression Paste R] at point 1, 2, 3, and 4 width was 10.95, 10.44, 11.16 and 10.67 respectively. Calculated Coefficient of Variance value with Viscogel tissue conditioner is 0.70 % and with zinc oxide eugenol paste 1.04 %.CONCLUSIONWith these results and statistical analysis, with 5% of level of significance (as alpha = 0.05) i.e. 95% confident, we found enough evidence to conclude that usage of Viscogel tissue conditioner is more effective and accurate than zinc oxide eugenol impression paste in neutral zone technique.

Salvation of a severely resorbed mandibular ridge with a neutral zone technique.

The objective of any prosthodontic service is to restore the patient to normal function, contour, esthetics, speech, and health. An optimum denture stability is difficult to achieve in conventional complete dentures. This problem is more magnified in mandibular dentures. The design of prostheses to replace lost teeth and resorbed ridges is largely determined by the position and amount of morphological change in the denture-bearing area of the jaws. A neutral zone may be defined as the space where, during function, the forces of the lips and cheeks pressing inward neutralize the forces of the tongue pressing outward. The neutral zone concept implies acquired muscle control, especially by tongue, lips, and cheeks toward the denture stability. Advocates of the neutral zone concept agree that a lack of favorable leverage is observed when teeth are positioned directly over the ridge. By employing the neutral zone concept, the dislodging muscle energy can easily become a retentive and stabilizing force.