OBJECTIVETo learn retention and stability of linear occlusal complete dentures by investigating the subjective feelings of patient and the value of retention force.

METHODSStatic retention forces of maxillary and mandibular dentures were measured for 25 patients wearing linear occlusal dentures by using Hz-1 retention dynamometer. The subjective feelings of patients in functional state were gained simultaneously through questionnaire.

RESULTSLinear occlusal dentures demonstrate good retention in static and dynamic state. Among patients with severe resorption of residual ridge (RRR), mandibular linear occlusal dentures (shown good retentive subjective feelings) demonstrate significantly smaller retention force than those with slight or medium degree of RRR. There is no correlation between the subjective feelings and the values of retention forces of mandibular dentures. The subjective feelings of patients wearing new linear occlusal dentures are much better than that of old anatomic occlusal dentures.

CONCLUSIONLinear occlusal dentures improve the performances of dentures by enhancing their stability during mastication movement.

Aged ; Aged, 80 and over ; Dental Occlusion ; Denture Design ; standards ; Denture Retention ; Denture, Complete ; standards ; Denture, Complete, Lower ; standards ; Denture, Complete, Upper ; standards ; Female ; Humans ; Male ; Middle Aged

OBJECTIVETo analyze the energy relieving effect of different thickness of mucosa beneath mandibular complete denture and try to analyze clinical question of prosthodontics using energy analysis methods.

METHODSA 3-DFE model of the mandibular complete denture and its supporting tissue were set up. Their elastic deformed energy and the percentage in the whole system were respectively calculated when mucosal thickness was different.

RESULTSThe percentage of mucosal elastic deformed energy grew from 44.53% to 52.91% and 57.91% with its different thickness under static loads.

CONCLUSIONSThe energy relieving effect of mucosa grows with its thickness and the approach of energy analysis is one of effective method on oral biomechanics questions.

Biomechanical Phenomena ; Dental Stress Analysis ; Denture, Complete, Lower ; Elasticity ; Finite Element Analysis ; Humans ; Mouth Mucosa ; anatomy & histology

OBJECTIVETo evaluate the in vivo retentive forces of mandibular complete overdenture with Magfit attachments, as well as the relation between the location of magnetic attachments and the retentive forces of the denture.

METHODS5 patients were selected and treated with mandibular complete overdentures retained by Magfit EX600 and MD800 attachments. A strainometer was used to measure the retentive forces in anterior, central and posterior parts of the overdenture before and after magnets were set. The vertical and anterior-upper 60 degrees retentive forces of the overdenture were measured one month later.

RESULTSThe retentive forces of the overdentures after setting magnets were significantly greater than that before magnets were set (P < 0.05). There was no significant difference in retentive forces between the different parts (P > 0.05). The retentive force in vertical direction was greater than that in anterior-upper 60 degrees direction (P < 0.025).

CONCLUSIONMagnetic attachments can significantly improve the retention of mandibular complete overdenture. The location of magnetic attachments greatly influences the retentive force of the overdenture.

Aged ; Aged, 80 and over ; Dental Prosthesis Design ; methods ; Dental Prosthesis Retention ; instrumentation ; Dental Stress Analysis ; Denture Precision Attachment ; Denture, Complete, Lower ; Denture, Overlay ; Electromagnetic Fields ; Female ; Humans ; Magnetics ; instrumentation ; Male ; Materials Testing ; Stress, Mechanical