Smart Digital Denture Conversion (SDDC), a Technique for Full Arch Immediate Loading: A Randomized Trial
Phase: NA
Conditions: Complete Edentulism
Sponsor: Ain Shams University

 
 
Smart digital denture conversion (SDDC), a technique for 
full arch immediate loading. 
 
 
 
 
 
 
 
 
 
 
 
Document Date: November 1, 2023 

 
 
Topic 
 
Page 
I. 
Abstract 
 
1 
II. 
Background 
 
2 
III. 
Research Question 
 
3 
IV. 
Aims (Objectives) 
 
4 
V. 
Hypothesis 
 
4 
VI. 
Ethical Considerations  
4 
VII. 
Study Design 
 
5 
VIII. Material and Methods 
Study Setting 
Sample Size 
Study Procedures 
 
5 
IX. 
Statistical Analysis 
 
8 
X. 
Funding of the Study 
 
8 
XI. 
References 
 
9 
 
 

1 
 
 
I. Abstract 
 
State of the Problem 
In full arch implant rehabilitations, immediate loading is one of the advantageous aspects of these 
interventions. However, the conventional denture conversion technique is troublesome for both 
practitioner and the patient. 
Aim of the Study 
This article presents a smart digital approach to design and construct a screw retained immediately 
loaded full arch implant supported bridge based on the pre-treatment complete denture. 
Materials and Methods 
After intra oral scanning of the ridge form, implant positions, the denture is used to scan the 
intermaxillary relation and tooth positions and the fixed interim is designed and milled from 
PMMA. This technique is applicable when a single arch is treated or for bimaxillary implant 
rehabilitation cases. In this study 30 patients were grouped into two groups; group I in which a 
converted denture was made conventionally and Group II in which a converted denture was made 
digitally. General satisfaction, chair side working time, and esthetic outcome of the prostheses 
were recorded and quantified with a verbal rating scale following insertion of implant-supported 
prosthesis.  
 
 

2 
 
II. Background 
Immediate implant loading has been a reliable procedure for rehabilitation of edentulous 
and prospective edentulous arches. It shortens the treatment time, reinstate esthetics, function, and 
endorses the patient acceptance to the treatment. 1,2 
Using a rigid material for construction of the immediately loaded fixed interim is an 
absolute requirement for the overall success of the treatment as it ensures splinting, cross arch 
stabilisation and proper force distribution.3-5   Denture conversion technique was proposed by 
Balshi and Wolfinger for provisionalization of full arch implant rehabilitation cases with success 
rate of 80%. Most of the failures were in the form of fractures of the converted dentures due to 
hollowing and the holes made in the denture to ensure passive seating and pickup of the titanium 
sleeve abutments using self-cure acrylic resin. These different material phases and compromised 
flange thickness are the main causes of fractures.6,9  
Using a highly cross-linked resins such as Polymethyle Methacrylate PMMA would reduce 
the incidences of interim fractures and thereby enhancing the success rate of the implant 
treatments.7 
An alternative workflow for construction of the fixed interim requires impressions, model 
production, and jaw relation records then digitizing all these data then designing and milling the 
restoration. Fulfilling these steps is inconvenient and time consuming in addition to the limitations 
of the physical records.10 So, a digitalised workflow would be time and cost effective in such cases. 
However, acquisition of the ridge form, implant positions and jaw relation in edentulous patients 
are difficult and unpredictable. So, a modified workflow is presented in this article which is 
specifically tailored for immediate loading of full arch cases resulting in significant improvement 
of the treatment outcomes. 
 

3 
 
III. Research Question 
Will the digital conversion of the pre-treatment complete dentures in immediately loaded full arch 
implant cases, introduce a more time saving solution and better patient satisfaction? 
Problem 
 
the conventional denture conversion technique 
is troublesome for both practitioner and the 
patient 
Intervention 
 
An alternative workflow for construction of 
the fixed interim requires impressions, model 
production, and jaw relation records then 
digitizing all these data then designing and 
milling the restoration. 
Comparator 
 
A conventional denture conversion will be 
done following the conventional fabrication 
technique. 
Outcome 
 
General satisfaction, chair side working time, 
and esthetic outcome of the prostheses with a 
verbal rating scale following insertion of 
implant-supported prosthesis.  
 
Time of Follow-up 
 
One week for fabrication of the denture 
digitally, but no follow-up is needed. 
 
Study Settings 
 
Removable 
Prosthodontics 
Department, 
Faculty of Dentistry, Ain Shams University. 
 
 
 
 
 
 

4 
 
IV. Aim of the Study Outcomes and Clinical Relevance 
 
Aim 
The objective of this study is to find out if a digitalised workflow will be time and cost 
effective when converting the pre-treatment complete denture into a screw retained immediately 
loaded full arch implant supported bridge. 
Outcome 
General satisfaction, chair side working time, and esthetic outcome of the prostheses with 
a verbal rating scale following insertion of implant-supported prosthesis.  
Clinical Relevance 
Providing proof for the use of a modified workflow which is specifically tailored for 
immediate loading of full arch cases resulting in significant improvement of the treatment 
outcomes. 
V. Hypothesis 
The null hypophysis considered for this study is that there will not be a significant statistic 
difference in patient satisfaction between the digitalized modified workflow presented in this 
article and the conventional one. 
IV. Ethical Considerations 
In this study each patient will be rehabilitated with a full arch implant supported prosthesis 
when immediate loading will be the chosen protocol in which a fixed interim prosthesis should be 
properly constructed after the conversion of a pretreatment complete denture either following the 
conventional fabrication technique or following the digitalized technique proposed.  
• Risks and Discomfort to Patients: There are no serious risks regarding this study, however, 
mucosal irritation, slight pain, and discomfort are commonly related to conventional procedures 
during denture conversion. 
• Minimization of Risk: mouth rinses and oral gel medications will be prescribed in case of 
mucosal irritation. 
• Criteria for Discontinuation of Study or Enrollment or Modification of Intervention: In 
case of patient sickness, incompliance, or refusal to continue in treatment. 

5 
 
• Benefits to the Patients and to the Community: Digitized database for the patient’s ridges, 
implant positions and intermaxillary relation will save time, and effort for both the dentist and the 
patient. 
• Privacy: Privacy for participants is protected by several procedures, such as informed consent 
and transparency in how patient data is accumulated and analyzed. Data will be kept in a specific 
folder on a computer with passwords known only by the main operator. 
• Confidentiality: Confidential data of the patients will be privately kept with the main operator. 
• Data Management: Data will be saved in a specific folder with passwords known only by the 
main operator on his personal computer. 
• Consent Procedures if Applicable: Before the provision of the treatments, each patient will 
read and sign a consent form supplied by the ethical committee of the Faculty of Dentistry, Ain 
Shams University, written in the Arabic language. The consent describes the steps of each 
procedure, their rights, and their role in the study. The consent will be kept with the main operator. 
• Adverse Event Reporting: Any adverse reaction will be reported and written in the patients’ 
data folder. 
V. Study Design 
This is a clinical cross over study. 
VI. Materials and Methods 
Study Settings 
Faculty of Dentistry – Ain Shams University. 
Sample Size Calculation 
Sample size calculation was performed using G*Power version 3.1.9.7 based on the results 
of previous studies. A power analysis was designed to have adequate power to apply a two-sided 
statistical test of the null hypothesis that there is no difference between the tested items. By 
adopting an alpha level of (0.05) and a beta of (0.2), i.e., power =80% and an effect size (d) of 
(1.050) calculated based on the results of previous studies. (23,24) The predicted sample size (N) is 
(30), i.e., 15 samples per group (n = 15).  
Study Procedures 
1. Sample Grouping 

6 
 
This study will comprise two equal groups of converted dentures based on their fabrication 
techniques in pateintes rehabilitated with a full arch implant supported prosthesis as follows: 
Group I: fifteen dentures were converted conventially to be used as a fixed interim prosthesis 
for immediate loading. 
Group II: fifteen dentures were converted digitally to be used as a fixed interim prosthesis for 
immediate loading. 
2. Patient selection 
Thirty patients will be selected from the outpatient clinic of the Oral and Maxillofacial 
Prosthodontics Department, Faculty of Dentistry, Ain Shams  
• Inclusion criteria 
-Nonsmokers 
-Free from any systemic disease 
-Non-bruxers 
-With sufficient quality and quantity of bone 
-Prepared to comply with the follow-up and maintenance program 
• Exclusion criteria 
− Patients with bad oral hygiene. 
− Patients with limited mouth opening. 
− Vulnerable groups. 
− Uncooperative patients. 
• Patient evaluation 
* History 
Precise medical and dental history will be taken from all patients. 
* Examination 
Comprehensive extraoral and intraoral examinations will be carried out to verify patients 
fulfilling the selection criteria. 
3. Clinical and Laboratory Procedures 
For both groups, multiunit abutments will be inserted for each implant and secured to them 
according to the recommended torque. A small amount of putty rubber base will be mixed and 

7 
 
placed into the fitting surface of the pre-treatment denture, which then will be seated intraorally to 
mark the sites of the multiunit abutments. The denture will then be relieved over the marked sites 
until it was fully seated without interference. 
For group I a conventional denture conversion will be made. For group II; the denture will be 
scanned extraorally using intraoral scanner. An intra oral scan will be made for the ridge form and 
multiunit abutments scan bodies and the scan will be extended to include the buccal and labial 
aspect of the ridge following the continuous scanning strategy.8 
A scan of the opposing arch will be done then a large vent hole will be drilled in the denture, 
removing a portion of the flange and anterior teeth while maintaining the integrity of the lingual / 
palatal aspect to connect to the other side base and teeth. The denture will be inserted intraorally 
and the patient will be instructed to bite in centric occlusion to make an intra oral bite scan which 
records the exposed area of the ridge, the opposing arch, and the remaining portion of the denture. 
Alignment of scans will be done on Medit compare application. These scans will be exported to 
the design software and alignment will be done by a software as well, virtual alignment of all scans 
to each other will be performed except for the denture scan which will be loaded separately as a 
pre-operative wax up. On the aligned scans, multi-unit abutments scan bodies will be matched to 
the digital library scan bodies and virtual multiunit abutment analogues will be generated then, 
titanium sleeves abutments will be selected. Alignment of denture scan to the jaw scan guided by 
the bite scan will be done and then teeth will be arranged, guided by the denture scan. Design of 
virtual gingiva will be made with flat fitting surface without overhangs or ridge lap parts. 
The screw access holes will be aligned and the area surrounding these channels will be thickened. 
 The STL file will be exported for millin from shaded PMMA disc A 3.5. After milling, 
the gingival portions will be coated with pink or red resins, NextDent Base and curing will be 
done. Titanium sleeve abutments will be cemented with the proper length to their respective sites 
with resin cement and cured. The interim fixed PMMA bridge will be delivered intra orally by 
sequential screwing of the prosthetic screws after verification of the seating and the proper tissue 
contact. Occlusion will be checked and equalised intraorally to establish centric balance with the 
opposing arch. Then the prosthetic screws will be torqued, and screw access holes will be sealed 
with flowable resin. 
 
 

8 
 
4. Methods of Evaluation 
General satisfaction, chair side working time, and esthetic outcome of the prostheses were recorded 
and quantified with a verbal rating scale following insertion of implant-supported prosthesis. 
Questionnaire about patient satisfaction level with different techniques of 
denture conversion: 
 
Questions  
0 
1 2 
3 
4 
5 
1 
How do you feel about the pleasure you get from food compared to 
your complete denture? 
 
 
 
 
 
 
2 
With respect to appearance, how satisfied are you with your fixed 
restoration in comparison to your denture? 
 
 
 
 
 
 
3 
With respect to speech, are you satisfied with your current fixed 
prosthesis? 
 
 
 
 
 
 
4 
How comfortable were you during the process of denture fixation? 
 
 
 
 
 
 
5 
With respect to time, how satisfied are you with the process of 
denture fixation? 
 
 
 
 
 
 
 
IV. Data Management 
The data will first be recorded manually and then transferred into digital form. The obtained data 
will be stored in the Oral and Maxillofacial Prosthodontics Department, Ain Shams University 
library. 
V. Statistical Analysis 
The obtained data will be recorded, tabulated, and statistically analyzed using the Mann-Whitney 
U Test was used for comparison between the two groups. Statistics was done with IBM SPSS 
statistics v20. Data was presented as median and interquartile range. 
 
 

9 
 
VI. Funding 
This study will be self-funded. 
 
 
 
 
VII- References 
1. Nj Z. Immediate and early implant loading protocols: A literature review of clinical studies. J 
Prosthet Dent. 2005;94(3):242–58.  
2. Biscaro L, Ferlin P, Becattelli A, Vigolo P. Prosthetic procedure for simultaneous immediate 
loading of opposing edentulous arches. J Prosthet Dent [Internet]. 2014;112(4):713–6.  
3. Skalak R. Biomechanical considerations in osseointegrated prostheses. J Prosthet Dent 
[Internet]. 1983;49(6):843–8.  
4. Rangert B, Jemt T, Jörneus L. Forces and moments on Branemark implants. Int J Oral 
Maxillofac Implants. 1989 Autumn;4(3):241–7.. 
5. Brunski JB. Biomechanical aspects of the optimal number of implants to carry a cross-arch full 
restoration. Eur J Oral Implantol 2014;7:S111-S131. 
6. Misch CM. Immediate loading of definitive implants in the edentulous mandible using a fixed 
provisional prosthesis: The denture conversion technique. J Oral Maxillofac Surg 2004;62:106-
115. 
7. Zafar MS. Prosthodontic Applications of Polymethyl Methacrylate (PMMA): An Update. 
Polymers (Basel) 2020;12(10):2299. 
8. Imburgia M, Kois J, Marino E, Lerner H, Mangano FG. Continuous Scan Strategy (CSS): A 
Novel Technique to Improve the Accuracy of Intraoral Digital Impressions. Eur J Prosthodont 
Restor Dent 2020;28:128-141. 

10 
 
9. Balshi TJ, Wolfinger GJ. Conversion prosthesis: a transitional fixed implant-supported 
prosthesis for an edentulous arch--a technical note. Int J Oral Maxillofac Implants. 1996;11:106-
11 
10. Mobilio N, Fasiol A, Mollica F, Catapano S. Effect of Different Luting Agents on the Retention 
of Lithium Disilicate Ceramic Crowns. Materials (Basel). 2015;8:1604-1611.