Table 2 Studies of the finite-element analysis

Cunha [23]

34, 35, 36, and 37

2-D

Class 1 (partially edentulous Hemi-arches)

Homogeneous, isotropic, and linearly elastic, except for the PDL, which was considered a non-homogeneous structure

Not described

Only rest (from the illustration)

Metal framework

Three patterns: 35, 36 or 37

1

Healing abutment

Memari [24]

35, 36, 37 and 45, 46, 47

3-D

Class 1

All living tissues were presumed elastic, homogeneous, and isotropic

Not described

Only rest (from the illustration)

Metal framework

Three patterns: 35, 45 or 36, 46, or 37, 47

2

Not described

Healing abutment (from the illustration)

Xiao [25]

34, 35, 36, 37 and 44, 45, 46, 47

3-D (CT-based patient-specific model)

Class 1

All materials were presumed to be linearly elastic, homogeneous, and isotropic

Classic RPA clasps

Metal framework

Three patterns: 45, 46, or 47

1

Rigid telescopic crown

Ortiz-Puigpelat [26]

34, 35, 36, 37 and 44, 45, 46, 47

3-D (CT-based patient-specific model)

Class 1

Isotropic linear for all elements of the model, except for the PDL of the canine, which was established as non-linear in geometry

Akers clasp

Metal framework

Four patterns: 35, 36, or 37 or control (without implant)

1

Locator attachment

Ohyama [27]

35, 36, and 37

3-D [a skull replicative model (P10–SB1, Nissin, Kyoto, Japan)]

Class 2

Isotropic structural non-linear static analysis

RPI clasp

A mesial rest for the right primary premolar, an Akers clasp for the right first molar, and a lingual bar

Three patterns: 35, 36, or 37

1

Two patterns of healing abutment: mucosal-level (2-mm-height)

Jia-Mahasap [28]

35, 36, 37 and 45, 46, 47

3D (based on the scanned data of the mandibular model, RPD framework, and mini dental implant)

Class 1 (entire mandible)

Linearly elastic, homogenous, and isotropic

RPA clasp

Cobalt–chrome–molybdenum framework, with lingual bar

Three patterns: 35, 36, or 3716.5 mm, respectively

1

Equator attachment

Cunha [23]

Multi-point loading (on abutment tooth and denture): vertical force of 50 N on each cuspid point and 400 N in the models with RPD

The von Mises equivalent stress

The presence of an implant reduced the denture displacements

Stress in the PDL and spongy bone was the largest in CRPD, followed by implant at P2, M1, and M2 second molar

Stress in cortical bone was the largest in CRPD, followed by implant at M2, M1, and P2

The stress in fibromucosa was the largest in CRPD, followed by the implant at P2, M2, and M1

Memari [24]

Multi-point loading (on abutment tooth and denture): loading was 10 N at each tooth location (on the second molar, the first molar, the second premolar, and the first premolar) in the vertical direction. (total load of 80 N at both sides)

Displacement and von Mises stress

Stress on the abutment tooth was the largest in the implant at P2, followed by M1 and M2

The largest stress was observed in the implant at M2

Cortical bone stress and implant stress were the largest in the implant at P2, followed by M2 and M1

Spongy bone stress was the largest in the implant at M2, followed by M1 and P2

Xiao [25]

Multi-point loading (on denture): three different static load scenarios on the center point of each simulated artificial tooth: 100 N in the vertical direction, 100 N at a 45° inclination buccolingual direction, 20 N in the horizontal buccolingual direction

The maximum EQV stress value

The maximum mucosa displacements

Vertical loading condition: stress on the PDL of the abutment tooth was the largest in CRPD, followed by implant at M2, P2, and M1. Stress on mucosa under the denture base was largest in CRPD, followed by P2 and M2 (similar), and M1. In cortical and spongy bones, stress was the largest in the implant at P2, followed by M2 and M1

Oblique loading condition: stresses on the PDL of the abutment tooth, mucosa under the denture base, and bones were the largest in CRPD, followed by implant at M2, P2, and M1

Horizontal loading condition: stress on the PDL of the abutment tooth was the largest in CRPD, followed by implant at M2, P2, and M1. Stress on mucosa under the denture base and cortical bone was largest in CRPD, followed by P2, M2, and M1 (similar). Stress in spongy bone was the largest in the implant at P2, followed by M1 and M1

Ortiz-Puigpelat [26]

Multi-point loading: (on tooth and denture)

Vertical force of 200 N directed towards occlusal surface

The oblique inclination of a 30° angle in relation to the occlusal plane

Denture displacement von Mises stress maps in MPa, non-linear strains in % of the different structures

Mandible stress was the largest in CRPD, followed by implant at M2, M1, and P2

Soft tissue stress was the largest in the implant at P2, followed by M1, CRPD, and M2

Implant stress was the largest in the implant at P2, followed by M2 and M1

PDL (abutment tooth) stress was similar in all conditions, but PDL deformation was the largest in CRPD, followed by implant at M1, M2, and P2 (M2 and P2 are similar)

Abutment tooth stress was largest in CRPD, followed by implant at M1, M2, and P2 (M2 and P2 are similar)

Ohyama [27]

Loading of the mandible by masticatory muscles during biting in the intercuspal position

The displacement of the abutment tooth (P1) and denture base

Minimum principal stress of the cortical bone around the implant neck

The denture base and tooth displacement at an abutment height of 0 mm was larger than 2 mm

In abutment height of 0 mm, displacement of abutment tooth in the implant at P2 was largest, followed by M1 and M2. In abutment height of 2 mm, displacement of abutment tooth in the implant at M2 was largest, followed by M1 and P2

In abutment height of 0 mm, minimum principal stress in the implant at M2 was the largest, followed by M1 and P2. In abutment height of 2 mm, minimum principal stress in the implant at P2 was the largest, followed by M1 and M2

Jia-Mahasap [28]

Two-point loading (on denture): the vertical load of 100 N was applied bilaterally on the denture base at 9 and 14 mm distal from the first premolar abutment tooth (50 N each)

The volume average of von Mises stress was calculated on the abutment tooth, mini dental implant, and surrounding bone

Stress in the abutment tooth was the largest in the implant at P2, followed by M1 and M2

The stress of the implant was largest in the implant at M1, followed by P2 and M2

Stress in the bone was largest in the implant at M1, followed by M2 and P2