Application of valplast dentures in the temporary restoration of single missing anterior tooth / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the value of valplast dentures in the temporary restoration of single missing anterior tooth.</p><p><b>METHODS</b>Totally 76 patients who needed temporary restoration of single missing anterior tooth were involved and equally divided into two groups according to their own choices of procedures: group A, with valplast dentures as their temporary dentures and group B, with conventional removable partial dentures as their temporary dentures. Meanwhile,38 patients who had their single anterior teeth pulled out and did not need temporary dentures were enrolled as control group without any temporary restoration, and impressions were taken immediately before the temporary dentures were used (2 weeks after tooth extraction) and before the initiation of permanent restorations (97-100 days after tooth extraction).The heights of clinical crowns of the adjacent teeth were also recorded twice from plaster models made from the impressions.The height of labial gingiva recession was calculated as the difference between the two heights recorded.</p><p><b>RESULTS</b>The height differences of clinical crowns of the adjacent teeth was 0.5mm (range: 0.0-1.2mm) in group A, which was significantly larger than those in group B [0.0mm;(range: 0.0-0.6mm)](P<0.05) and in group C[0.0mm;(range: 0.0-0.4mm)](P<0.05).However, the difference was not significant between group B and group C (P>0.05).</p><p><b>CONCLUSION</b>Application of valplast denture as temporary denture may cause labial gingival recession of the adjacent teeth, and therefore is not suitable for the restoration of single missing anterior tooth.</p>

Comparison of the influences of gold alloy metal crown and ni-cr alloy metal crown on gingival health / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the influences of gold alloy metal crown and Ni-Cr alloy metal crown on gingival health.</p><p><b>METHODS</b>Totally 20 patients requiring one metal crown restoration were divided into the gold alloy metal crown group (n=9) and Ni-Cr alloy metal crown group (n=11). The contra-lateral homonymy natural healthy teeth served as controls. Before the tooth preparation and 6 months after crown placement, the weight of gingival crevicular fluid (GCF) of each tooth (included the test teeth and the control teeth) was measured, and the probing depth and the sulcus bleeding index of each tooth were also recorded.</p><p><b>RESULTS</b>In the gold alloy metal crown group, the weight of GCF detected before the tooth preparation was significantly larger than that detected 6 months after restoration (P<0.05). In the Ni-Cr alloy metal crown group, the sulcus bleeding index recorded 6 months after restoration was significantly larger than that recorded before the tooth preparation (P<0.05). The other experimental indicators were not significantly different before and after restoration.</p><p><b>CONCLUSION</b>The gold alloy metal crowns will not cause obvious harm to the periodontal tissues of the abutments shortly after restoration, while the Ni-Cr alloy metal crowns may increase the risk of sulcus bleeding.</p>