Electromyographic evaluation of the masseter and temporalis muscles activity in patients with complete denture, implant supported and implant retained mandibular overdentures. a cross-over study

This study was conducted to compare the electromyographic [EMG] activity of both masseter and the anterior temporalis muscles in patients with: Conventional complete dentures, Implant supported overdentures without attachments and, Implant retained overdentures with locator attachments.
Material and methods: Six completely edentulous male patients with atrophied mandibular ridges received upper and lower conventional complete denture. EMG activity were measured for both masseter and the anterior temporalis muscles during clenching without food, clenching hard (carrot) and soft (banana) foods. Measurements were made at time of denture insertion, one month and two months after. Two implants were installed in canine regions of the mandible. After osteointegration, healing abutments were connected and the mandibular denture were relined with hard acrylic resin. Measurements were repeated, then healing abutments were replaced with locator attachments, and measurements were repeated again.
Results: The highest EMG activity/amplitude of masseter and temporalis muscles, were noted with locator overdentures, and the lowest values were observed with conventional dentures. There was no statistically difference in muscle activity between implant supported overdentures and complete dentures. For all groups, muscle activity for masseter and temporalis muscles increased with advance of time. For both groups, muscle activity was significantly higher during clenching of hard food than clenching without food or with soft food
Conclusion: Within the scope of this study, implant retained overdentures are recommended for edentulous patients rather than conventional complete dentures or implant supported overdentures as it improves EMG activity/amplitude of masseter and temporalis muscles.