Functional and Patient-Centered Treatment Outcomes with Mandibular Overdentures Retained by Two Immediate or Conventionally Loaded Implants: A Randomized Clinical Trial

Abstract

This study aims to assess the treatment outcomes (functional and subjective) of mandibular overdentures retained on two implants with or without an immediate loading protocol. In this randomized clinical trial, twenty fully edentulous patients were treated with a mandibular two-implant-retained overdenture and a complete new maxillary denture. In half of the sample, the implants were loaded immediately by means of VulkanLoc® abutments after emplacement of the implant, but in the counterparts, these VulkanLoc® abutments were connected to implants two months after the surgery (conventional protocol), and until that time the dentures were retained by healing abutments. Treatment outcomes were assessed at two, six, and twelve months after surgery. Functional outcomes were calculated according to masticatory performance, estimated by the mixed fraction of a two-coloured chewing gum after five, ten, and fifteen chewing strokes, by the occlusal force recorded by pressure-sensitive sheets, and by the bioelectrical muscular activity. The subjective outcomes of the treatment were assessed using both the oral satisfaction scale (visual analogue scale) and the Spanish version of the Oral Health Impact Profile (OHIP-20). The findings of the present study show that new complete dentures resulted in significant improvements in chewing ability, patient satisfaction, and oral health-related quality of life and that subsequent implant-retained overdentures produced further and faster significant improvements. The loading protocol may influence those positive self-reported outcomes rather than the objective functional evaluations.

Patient-Centered Treatment Outcomes with Full-Arch PEEK Rehabilitation Supported on Four Immediate or Conventionally Loaded Implants. A Randomized Clinical Trial

“…Focusing on satisfaction and quality of life, a clear improvement after prosthetic treatment was observed with satisfaction significantly higher among the IL than among the CL group ( Table 7 ), but not in terms of quality of life ( Table 8 ). In agreement with other studies [ 29 , 41 , 42 ] using the same assessment tools, the postoperative satisfaction and quality of life scores reported in the present study are higher than those observed among patients treated with two-implant retained overdentures. Specifically, the major improvements were observed among pain , functional limitation , and physical disability OHIP-dimensions ( Table 8 ), as found in other studies [ 29 , 43 ].…”

“…In any case, the pre–post comparisons show that the occlusal area and the occlusal loading increase gradually from baseline conditions to fixed rehabilitation with PEEK-NFC ( Table 4 ). Nevertheless, the present study found greater areas of occlusion than that reported by Montero [ 29 ] (26.1 ± 15.7 mm 2 ); Baca et al [ 30 ] (21.0 ± 10.9) mm 2 ; Suzuki et al [ 31 ] (10.3 ± 5.2) mm 2 ; Iwaki [ 32 ] (7.0 ± 4.3) mm 2 , after using Dental PRESCALE in a comparable group of patients treated with two-implant overdentures [ 29 , 32 ] or conventional fixed rehabilitations [ 30 , 31 ]. These differences could be partially explained because of the distinct sensitivity of the pressure sheet (type 50 H, 97 μm thick) used in some studies [ 30 , 31 , 32 ] instead of the one used in the present study (MS type for medium pressure, 110 μm thick), but also because of the greater occlusal arrangement implemented by customized milled NFC crowns present on the present PEEK-NFC rehabilitations which is presumably better than that achieved when acrylic standardized teeth are used.…”

“…Moreover, patients perceived they could chew better ( Table 6 ), and accordingly, were more satisfied with chewing ( Table 7 ) and lower impact on the functional domain of OHQoL ( Table 8 and Table 9 ) after treatment. Similar findings had been reported after implant rehabilitation with mandibular overdentures [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], but evidence from fixed hybrid rehabilitation is scarce [ 37 , 38 ], although, fixed rehabilitations are expected to be, at least, functionally equivalent to overdentures [ 39 , 40 ].…”

“…According to our findings, the final occlusal load (483.0 ± 280.1) N is lower than that reported by Baca [ 30 ] for patients treated with fixed porcelain-fused-to-metal rehabilitations (516.6 ± 85.6) N of 14 units but higher than that observed by the same author for patients treated with those rehabilitations distributed on 12 units (254.9 ± 116.4) N. In any case, the occlusal load of the PEEK-NFC is greater than that recorded by patients treated with two-implant retained overdentures (292.7 ± 163.2) N according to Montero et al [ 29 ]; Baca (416.3 ± 137.2) N [ 30 ]; Suzuki [ 31 ] (342.1 ± 163.6) N; Iwaki [ 32 ] (157.9 ± 60.3) N. The Dental PRESCALE system can accurately measure occlusal forces within the range from 20–80 N, but their readings are usually greater than the actual load [ 33 ].…”

“…In line with our results, Giannakopoulos et al [ 35 ] also found great data dispersion with the EMG recorder (Noraxon ® ), higher activity on masseters in comparison with temporalis muscles, and a stable right muscular asymmetry. A balanced muscular activity may be an indicator of functional improvements of the masticatory system and may be even more relevant than the magnitude itself of the bioelectric tone of the elevators muscles, as reported by Montero et al [ 29 ].…”