Table 5.

Study results of the included studies.

Author (Year)	Outcomes Reported	Data Collection Method	Length of Follow-Up	Biological Outcomes	Implant Survival and Success Rates	Patient Satisfaction and Oral Health-Related Quality of Life (OHRQoL)
Fonteyne (2019)	-Articulation - Oromyofunctional behaviour - Patient satisfaction - Quality of life	Articulation: Digitally with video camera Oromyofunction: 3-point rating scale Patient satisfaction: with oral health and speech via 10 cm VAS scale OHRQoL: OHIP-14	6 months	Not specified.	Not specified.	Satisfaction with oral health: increased from 67% to 83% Satisfaction with speech: increased from 77% to 84% OHRQoL: improved- OHIP score decreased from 21.97 to 8.23.
Elsyad (2013)	- Peri-implant bone loss around MI - Mobility - Patient satisfaction - Survival rate of MI	Peri-implant bone loss: Radiographically Mobility: Periotest instrument Patient satisfaction: with retention and chewing measured via 10 cm VAS scale Survival rate: Kaplan–Meier life table analysis	24 months	Mean vertical bone loss: Group I- 5.38 ± 1.65 mm Group II- 6.29 ± 2.33 mm Mobility: increased over time in both groups. Mobility of Group II > Group I at T2 and T3	Survival rate: Group I—78.4% Group II—53.8% (significant difference)	Patient satisfaction with retention: Group I-2.5 ± 0.84; Group II—1.0 ± 0.99 (no significant difference) Patient satisfaction with chewing: Group I- 7.9 ± 0.73; Group II- 8.22 ± 0.97 (significant improvement in both groups).
Van Doorne (2020)	- Implant stability at surgery - Patient’s perception of pain - Patient satisfaction - Survival rate - Success rate	Implant stability: Torque wrench Perception of pain: Numeric rating scale of 1 to 10 Patient satisfaction: ‘yes’/ ‘no’ questionnaire Survival rate: Kaplan–Meier life table analysis Success rate: When >5 MDIs are lost.	24 months	Not specified.	Survival rate: 82.3% Success rate: 93.5% Initial MDI failure rate: 17.3%. All MDI failures occurred in initial healing phase.	Average final patient satisfaction score was 8.6 ± 1.7. 96% of the patients would recommend this treatment to others.
Mundt (2013, 2015)	- Surgical and prosthetic complications - OHRQoL- Implant and prosthetic status Changes in bone level	Surgical and prosthetic complications: Data from patient records, oral examinations, and questionnaires. OHRQoL: OHIP-14 scale Implant and prosthetic status: Compared with participants records Changes in bone level: Radiographically	27.1 ± 12.8 months 2.2 ± 1 years	10.3% MDIs TBL of >2 mm 3.3% MDIs TBL of >3 mm	Survival rate: 94.3% 15 maxillary implants lost after insertion.	Significant improvements for all participants in all single questions regarding OHRQoL Retention rated very high in 9 (16.7%), fair in 44 (81.5%), and low in one denture.
Preoteasa (2014)	-MDI status - Overdenture status - Patient’s perception regarding treatment	MDI Status: Radiographically, clinical evaluation, self-reported peri-implant bleeding. Overdenture status: Self-reported Patient perception: Self-reported	36 months	11 MDIs presented with bone loss >1 thread.	MDI health status: 8 failed	Patients generally satisfied with aesthetics, retention, function (mastication and phonation). Complaints mainly associated with occasional pain to soft tissue supporting overdenture.
Tomasi (2013)	- Patient satisfaction - Clinical assessments - Survival rate	Patient satisfaction: 10 cm VAS scale and ‘yes’/‘no’ questionnaire Clinical assessment: Plaque score, BoP, and implant stability judged by percussion	12 months	Mean plaque score of 20% for maxillary and mandibular MDIs. Mean BoP score of 30%. Mean pocket probing depth was 2.3 mm with a range from 1 to 6 mm.	Implant failure rate was significantly higher in maxilla than the mandible, 43% and 15%, respectively. 6 out of 14 implants failed	All patients said ‘yes’ when asked if they were satisfied with their denture. Patient satisfaction with chewing ability increased from 4.5 to 9.0 Patient satisfaction with speech increased from 5.8 to 9.3 Patient overall denture satisfaction increased from 3.3 to 9.0