Comparison between the effect of splinted and segmented full arch mandibular implant supported prosthesis on peri-implant bone level changes

Background:The mandible has a tendency to flex inwards around the mandibular symphysis which is accompanied with
change in shape and decrease in mandibular arch width during opening and protrusion of the mandible.Therefore, the effect of
stresses due to mandibular flexure on both bone and restoration in edentulous implant-fixed restoration needs to be evaluated.
Aim: The aim of this study is to compare the effect of splinted and segmented mandibular full arch implant-supported prosthesis
on peri-implant bone level changes due to mandibular flexure.
Materials & methods: For this clinical study, fourteen patients with edentulous mandible and dentate maxilla were selected
following certain criteria to receive mandibular fixed hybrid prostheses. Patient’s lower denture was duplicated to clear acrylic
stent and used as a surgical guide to mark the entry point of each implant. After three months of placing the implants, the
patients were randomly divided into two groups.
Group I: patients received segmented mandibular implant supported full arch prosthesis.
Group II: patients received splinted mandibular implant supported full arch prosthesis.Crestal bone loss around distal implants
was evaluated using CBCT at zero, six months and twelve months.
Results: Results showed that for the 6 to 12 months time interval, there was a significant difference between the two groups
around implant number one where the bone loss for group II was 0.170.04± and for group I was 0.140.02± for implant number
one. Moreover, there was a significant difference between two groups around implant number three where the bone loss for
group II was 0.770.05± and for group I was 0.280.06±.Results also showed that for the 0 to 12 months interval. There was a
significant difference between the two groups around implant number one where the bone loss for group II was o.490.04± and
for group I was o.380.03± for implant number one. Moreover, there was a significant difference between two groups around
implant number three where the bone loss for group II was 1.240.06± and for group I was 0.550.10±.
Conclusion: Within the limitations of this study, it is recommended to construct a full arch segmented mandibular fixed
prosthesis rather than splinted.