Clinical Evaluation of Low-shrinkage Giomer Resin Composite Versus Resin-Modified Glass Ionomer in Treatment of Cervical Caries Lesions: A Randomized Clinical Trial
Phase: NA
Conditions: Caries, Cervical
Sponsor: Cairo University

 
 
Clinical Evaluation of Low-shrinkage Giomer Resin Composite 
versus Resin-Modified Glass ionomer in Treatment of Cervical 
Caries Lesions: A Randomized Clinical Trial 
 التقييم السريرى لمركب الراتنج ذ ى 
 االنكماش المنخفض مقابل االيونمر الزجاجى المعدل بالراتنج فى عالج
 آفات التسوس العنقية: تجربة سريرية عشوائية 
Protocol 
Submitted to the Faculty of Oral and Dental Medicine, Cairo University for partial 
fulfilment of the requirements of PhD degree in Conservative Dentistry 
                                      
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TRIAL REGISTRATION NUMBER: NCT05930548 
Date: 27-11-2023 
 
 
 
Faculty of Dentistry 
Cairo University 
2023 
 

 
 
I. Protocol checklist 
Section and topic 
Item no. 
Checked item 
Reported 
on page No. 
Reviewer’s 
check 
I. Administrative information 
1 
Title 
1 
 
2 
Protocol registration 
1 
 
3 
Protocol version 
1 
 
4 
Funding 
1 
 
5 
Roles and responsibilities 
1-2 
 
 
II. Introduction 
 
 
 
A) Background and Rationale 
6 a 
Research question  
3 
 
Statement of the problem 
3 
 
Rationale for carrying out the trial 
3-4 
 
Review of literature 
5-7 
 
6 b 
Choice of comparators 
7 
 
B) Objectives 
7 
Aim of the study  
8 
 
Hypothesis 
8 
 
C) Trial design 
8 
Trial design 
9 
 
 
III. Methods 
 
 
 
A) Participants, interventions 
& outcomes 
9 
Study setting 
10 
 
10 
Eligibility criteria 
10 
 
11 
Interventions 
10-11 
 
12 
Outcomes 
12 
 
13 
Participant timeline 
13 
 
14 
Sample size 
13 
 
15 
Recruitment 
13 
 
B) Assignment of interventions 
16 
Allocation 
 
 
16 a 
Random sequence generation 
(Randomization) 
14 
 
16 b 
Allocation concealment 
mechanism 
14 
 
16 c 
Implementation 
14 
 
17 
Blinding (masking) 
14 
 
C) Data collection, 
management, and analysis 
18 
Data collection methods 
15 
 
19 
Data management 
15 
 
20 
Statistical methods 
15 
 
D) Monitoring 
21 
Data monitoring 
15 
 
22 
Harms 
15 
 
23 
Auditing 
15 
 
 
IV. Ethics and dissemination 
24 
Research ethics approval 
16 
 
25 
Protocol amendments 
16 
 
26 
Informed Consent  
16 
 

 
 
 
 
 
27 
Confidentiality 
16 
 
28 
Declaration of interests 
16 
 
29 
Access to data 
16 
 
30 
Ancillary and post-trial care 
16 
 
31 
Dissemination policy 
16 
 
 
V. Appendices 
 
32 
Informed consent materials 
17-18 
 
 
VI. Statement of originality 
33 
Statement of originality 
19 
 
VII. References 
 
 
 
20-21 
 
 
Evidence based committee (Reviewers) 
 
Name 
Signature 
Date 
1. 
 
 
 
2. 
 
 
 
 
Research plan committee 
 
Name 
Signature 
Date 
1.  
 
 
 
2.  
 
 
 

1 
 
I. Administrative information: 
1. Title: 
Clinical Evaluation of Low-shrinkage Giomer Resin Composite versus Resin-
Modified Glass ionomer in Treatment of Cervical Caries Lesions: A Randomized 
Clinical Trial 
2. Protocol Registration: 
   The study is registered on www.clinicaltrials.gov under ID NCT05930548. 
3. Protocol version:  
 
   This is the second version of the protocol (July - 2023). 
4.  Funding:  
 
 
  This study is self-funded research by the main researcher.  
 
5. Roles and responsibilities: 
a) Principal Investigator 
• Assistant Lecturer of Conservative Dentistry, School of Dentistry, New Giza 
University.  
• Main Researcher and principal investigator responsible for patients' recruitment, 
screening, and clinical work. Also, responsible for writing the protocol, the research 
and the final manuscript retrieved from the research, baseline data collection, 
application of intervention. 
 
b) Main supervisor  
• Professor of Conservative Dentistry, Faculty of Dentistry, Cairo University.  
• The main supervisor and responsible for randomization, auditing, and data 
monitoring.  
• Supervising clinical work and contributing in writing and revising of the research 
work.  
 
c) co-supervisor: 
• 
Lecturer of Conservative Dentistry, Faculty of Dentistry, Cairo University. 
• 
The co-supervisor and responsible for outcome assessment.  
• 
Supervising clinical work and contributing in writing and revising of the research 
work.  
 
d) Name, Contact information and trial sponsor.  
• Faculty of Dentistry, Cairo university in Egypt  
• Mail: dentmail@dentistry.cu.edu.eg  
• Physical mail: 11 Al-Saraya Street, Al-Manial, Cairo, Egypt  
• Phone number: +2-0223634965  
 
e) Role of study sponsor and funders  

2 
 
 The principal investigator will fund the trial and all the materials required for the 
research. Funding will be sought and attempted upon approval of protocol. 
 
f) Role of steering committee 
 
Scientific committee of the Department of Conservative Dentistry 
• 
Ensuring that the research idea follows the research plan of the department. 
• 
Approve the protocol and the research after being reviewed by the evidence-based 
dentistry committee and ethical committees. 
• 
Picots revision.  
• 
Protocol revision.  
• 
Approving the methodology.  
• 
E-mail: sc.cons@dentistry.cu.edu.eg 
 
 
Medical Biostatistics Unit (MBU), Faculty of Dentistry, Cairo University:  
• 
Sample size revision. 
• 
E-mail: mbu@dentistry.cu.edu.eg 
Ethical Committee, Faculty of Dentistry, Cairo University  
• 
Responsible for ensuring that the trial does not violate participant’s privacy.  
• 
Undertake review free from bias and influence.  
• 
Provide advice to the researchers on all aspects of welfare and safety of research 
participants. 
• 
Protect dignity, rights, and well-being of the potential research participants.  
• 
Approval of informed consent form.  
• 
E-mail: rec@dentistry.cu.edu.eg 
 
g) Faculty and University board:  
Protocol approval following departmental approval. 
 

3 
 
II. 
Introduction 
A) Background and Rationale: 
6.a)  
Research Question: 
In patients with cervical caries lesions, will low-shrinkage giomer resin composite have 
similar clinical performance as resin-modified glass ionomer? 
Statement of the problem: 
Management of cervical lesions presents serious problems with any restorative 
material. The two most common reasons for restoration failure are secondary caries at the 
tooth-restoration interface and loss of retention (AlQranei et al, 2021). Class V lesions 
often exhibit a low retentive cavity configuration (C-factor); which is responsible for 
marginal gaps around the restorations (AL-Gailani et al, 2019). Cervical margins -lying in 
either dentin or cementum- show  unfavorable bonding performance (Kim et al, 2017), 
besides being usually subgingival where moisture control is difficult (Zhang et al, 2021). 
The subgingival margin is not clinically desirable due to difficulty in cleaning and 
increased biofilm accumulation (AlQranei et al, 2021). Therefore, the selection of the 
restorative material can be challenging. 
Resin composites are known for their high mechanical properties, excellent esthetic 
properties, and ease of clinical application. However, when compared with glass ionomers, 
resin composite has no cariostatic effect on tooth structure (Tonprasong et al, 2021). In 
addition, microleakage caused by polymerization shrinkage of resin composite leads to 
plaque accumulation and secondary caries (Huang et al, 2021). On the other hand, resin-
modified glass ionomer has many advantages, yet still it has lower weakness and esthetic 
properties compared to resin composite (AlQranei et al, 2021).   
 
Rationale for carrying out the trial: 
 
Many factors may impede the ability to achieve optimum cervical restorations with 
perfect marginal seal and long-term success (AlQranei et al, 2021). In high caries-risk 
patients, restoring class V caries lesions requires a material with high mechanical, esthetic, 
and biological properties.  
 
Resin-modified glass ionomer bonds chemically to tooth structure, and releases 
fluoride, but has poor esthetic and wear resistance properties. Resin composite has enhanced 
esthetic properties, but show high failure rates due to marginal discoloration, secondary 

4 
 
caries because of polymerization shrinkage (Toz-Akalin et al, 2023). Low-shrinkage giomer 
resin composite has been developed to deal with such defects. However more investigations 
are needed to compare between resin-modified glass ionomer and giomer low-shrinkage 
resin composite regarding microleakage and secondary caries in cervical carious lesions 
(AL-Gailani et al, 2019). 
Surface reaction PRG (S-PRG, known as giomer resin composite) is formed using 
fluoro-boro-aluminaosilicate glass. The surface layer of the glass filler is coated with a 
porous inorganic silica glass layer “surface-modified layer” through the sol-gel method. 
Then, polyacrylic acid is sprayed on the fillers leading to formation of glass ionomer 
phase. This glass ionomer phase is located between the surface modified layer and the 
surface of fluoro-boro-aluminaosilicate glass core, giving a tri-laminar structure. Such 
unique structure gives giomer resin composites the capability to release six key ions which 
are fluoride, aluminum, borate, silicate, strontium, and sodium ions. These ions exhibit 
acid neutralizing ability and help to prevent demineralization of enamel and dentin, 
reducing the possibility of secondary caries (Toz-Akalin et al, 2023).  
Giomers have other advantages such as low volumetric shrinkage and hence low 
polymerization shrinkage stresses. Thus, they can be used in areas where bonding to dentin 
is poor as the gingival margin in cervical lesions (AL-Gailani et al, 2019).  The most 
remarkable feature of the low-shrinkage giomer resin composite is its unique shrinkage of 
0.85 percent by volume. Such remarkable feature is due to the novel SRS (Steric Repulsion 
Structured) molecule which is designed to decrease polymerization shrinkage through 
molecular steric repulsion resulting in a stable restoration microstructure (AlQranei et al, 
2021). Thus, it is claimed to help prevent marginal leakage, secondary caries, marginal 
discoloration, and postoperative sensitivity.  Its main benefits are low volumetric shrinkage, 
chameleon effect, easy to handle, and sustained fluoride release and can be recharged due to 
the integrated S-PRG filler technology (Toz-Akalin et al, 2023).  
However more investigations are needed to compare between resin-modified glass 
ionomer and low-shrinkage giomer resin composite regarding microleakage and secondary 
caries in cervical carious lesions (AL-Gailani et al, 2019). 
 
Review of literature: 
The development of cervical lesions in permanent dentition may be related to 
carious or non- carious origin. Class V caries lesions may occur due to different factors 

5 
 
such as poor oral hygiene, dietary habits, or xerostomia (Akarsu et al, 2021).  
Management of cervical lesions presents serious problems with any restorative 
material. The two most common reasons for restoration failure are secondary caries at the 
tooth-restoration interface and loss of retention (AlQranei et al, 2021). Class V lesions 
often exhibit a low retentive cavity configuration (C-factor); which is responsible for 
marginal gaps around the restorations (AL-Gailani et al, 2019). Cervical margins -lying in 
either dentin or cementum- show unfavorable bonding performance (Kim et al, 2017), 
besides being usually subgingival where moisture control is difficult (Zhang et al, 2021). 
The subgingival margin is not clinically desirable due to difficulty in cleaning and 
increased biofilm accumulation (AlQranei et al, 2021). Therefore, the selection of the 
restorative material can be challenging. 
In this context, fluoride containing adhesive materials are considered ideal in 
restoring class V carious lesions. Resin modified glass ionomers (RMGI) are highly 
recommended in the restoration of cervical lesions. The most important advantages of glass 
ionomer are its chemical adhesion to the tooth structure, and its fluoride release (Toz-
Akalin et al, 2023). However, RMGI has lower weakness and esthetic properties compared 
to resin composite (AlQranei et al, 2021).   
Resin composites have been widely used in dental practice; because of their high 
mechanical properties, excellent esthetic properties, and ease of clinical application. 
However, when compared with glass ionomers, resin composite has no cariostatic effect 
on tooth structure (Tonprasong et al, 2021). In addition, polymerization shrinkage of resin 
composite is of major concern; where mechanical stresses are developed due to 
contraction leading to break the marginal seal between resin composite and tooth 
structure. Polymerization shrinkage can cause clinical issues such as restoration or tooth 
fracture, bond degradation and solubility, and microleakage (Algailani et al, 2022). The 
microleakage caused by polymerization shrinkage of resin composite leads to plaque 
accumulation and secondary caries (Huang et al, 2021). Thus, choosing a fluoride-
releasing and low-shrinkage resin composite may play a critical role in success of cervical 
restorations (AL-Gailani et al, 2019). 
The continued development of resin composites has led to the introduction of 
Giomer technology. By combining the characteristics of resin composite and glass 
ionomer, hybrid products called giomers have been obtained. Giomer resin composite 

6 
 
offers protection against caries, along with improved functional and esthetic properties; 
through incorporating particles of pre-reacted glass fillers (PRG) into the matrix of resin 
composite (Rusnac et al, 2019). The PRG-ionomer phase has the capability to release six 
key ions which are fluoride, aluminum, borate, silicate, strontium, and sodium ions. These 
ions exhibit acid neutralizing ability and help prevent demineralization of enamel and 
dentin, leading to decrease the possible incidence of secondary caries (Toz-Akalin et al, 
2023). This PRG technology provides giomer with both fluoride release and recharge, 
similar to glass ionomer while still maintaining the original physical properties of resin 
composite (Bheda et al, 2020). 
Beautifil™ II LS (Low shrinkage) giomer resin composite (Shofu Inc, Kyoto, 
Japan) shows both sustained fluoride release and recharge, and low volumetric shrinkage 
of less than 1% with low resultant polymerization shrinkage stress. Such remarkable 
feature is due to the novel SRS (Steric Repulsion Structured) molecule which is designed 
to decrease polymerization shrinkage through molecular steric repulsion resulting in a 
stable restoration microstructure (AlQranei et al, 2021). Thus, low shrinkage giomers are 
best indicated in class V cavities where the dentin bonding agent does not have high 
strength (Algailani et al, 2022). 
A recent clinical trial compared the clinical performance of giomers versus resin 
modified glass ionomer in proximal lesions. Marginal adaptation was higher in giomers 
than resin-modified glass ionomers after 12 months (Inthihas et al, 2019). Also, a 
systematic review investigated in vivo longevity of giomers compared to other adhesive 
restorative materials (hybrid resin composite, compomer, and RMGIC), and concluded that 
RMGIC was the most successful material in terms of biological properties while giomers 
had the longest survival rate (Bheda et al, 2020). An in-vitro study evaluated the surface 
roughness and fluoride release of Beautifil II and Fuji II LC (resin-modified glass 
ionomer). Resin-modified glass ionomer showed the highest fluoride release, while the 
giomer showed an intact, smooth surface with no irregularities as those found in glass 
ionomer. Thus, the smooth surface of giomers inhibit biofilm formation, decreasing the 
risk of dental caries and periodontal diseases (Komalsingsakul et al, 2022). Regarding the 
mechanical properties of giomers, it has exhibited a higher flexural strength value when 
compared to glass ionomer cements. The hardness values were twice as high for the 
giomer when compared to self-curing and light-curing glass ionomer cements (da Silva et 
al, 2021).  

7 
 
 
6.b) Choice of comparators: 
In our study, the comparator material will be light cured resin modified glass 
ionomer restorative. RMGI is recommended to restore carious cervical lesions; especially 
with its ability to inhibit secondary caries due to its fluoride releasing ability. The main 
advantage of RMGI is its capability to chemically bond to tooth structure, even in the 
presence of moist dentin. RMGI reaction can be achieved by both acid-base reaction 
(induced by glass ionomer component) and polymerization reaction (induced by resin 
component). Thus, RMGI has better mechanical properties, wear resistance, and improved 
esthetics compared with conventional glass ionomer (AlQranei et al, 2021). In addition, the 
coefficient of thermal expansion of glass ionomer which is similar to that of tooth structure, 
allows for proper marginal adaptation without marginal leakage (Bollu et al, 2016). 
 
 
 

8 
 
B) Study Objectives: 
7. Aim of the study: 
This study is conducted to evaluate the clinical performance of low-shrinkage giomer resin 
composite versus resin-modified glass ionomer in restoration of cervical caries lesions, 
using both Modified USPHS and Revised FDI criteria.   
Hypothesis: 
This study will be designed to test the null hypothesis that the low-shrinkage giomer resin 
composite will have the same clinical performance as resin-modified glass ionomer in 
cervical restorations, using both Modified USPHS and Revised FDI criteria. 
Primary Objectives: 
Measure the functional, biological, and aesthetic properties of both restorations (using 
Revised FDI criteria for direct restorations) at baseline, after 6, and 1 2 months. 
Secondary Objectives: 
Measure Cost-Effectiveness Analysis: Cost-effectiveness will be assessed by calculating the 
Incremental Cost-Effectiveness Ratio (ICER) and the Cost per Success Ratio (CPSR).  

9 
 
C) Trial Design 
• Study design: Randomized clinical trial (parallel group, two arm study). 
• Triple-blinded (participants, outcome assessors and statisticians). 
• Allocation ratio; 1:1  
• Framework: Superiority frame.  
 
PICOTS Elements: 
P (Population): Adult patients with cervical carious lesions in maxillary anterior teeth 
(ICDAS II score 4). 
I (Intervention): Low Shrinkage, giomer paste-like resin composite (Beautifil™ II LS, 
Shofu Inc, Kyoto, Japan). 
C (Comparison): Light cured resin reinforced glass ionomer restorative Fuji II LC® 
(GC Corporation, Tokyo, Japan). 
Outcomes: 
a) Primary Objectives: 
Measure the functional, biological, and aesthetic properties of both restorations (using 
Revised FDI criteria for direct restorations) at baseline, after 6, and 1 2 months. 
b) Secondary Objectives: 
Measure Cost-Effectiveness Analysis: Cost-effectiveness will be assessed by calculating the 
Incremental Cost-Effectiveness Ratio (ICER) and the Cost per Success Ratio (CPSR). 
 
T (Time): 12 months; with follow up at baseline, 6, and 12 months. 
S (Study design): Randomized clinical trial. 
 
 

10 
 
III. Methods 
A) Participants, interventions, and outcomes 
9. Study setting: 
This clinical trial will be held in the Conservative Dentistry Department, Faculty of 
Dentistry, Cairo University, Egypt. 
 
10. Eligibility Criteria of study population: 
Inclusion Criteria of participants: 
• Moderate to high caries-risk patients with carious cervical lesions (ICDAS 
score 4) in maxillary anterior teeth. 
• Patients with at least 20 teeth under occlusion. 
• Age: 25-50 years. 
• Asymptomatic vital teeth. 
• Co-operative patients approving to participate in the trial. 
Exclusion Criteria of participants: 
• Patients younger than 25 years old or older than 50 years old. 
• Extensive cervical lesions extending beyond proximal line angles. 
• Teeth with signs and symptoms of irreversible pulpitis or pulp necrosis. 
• Teeth supporting removable prostheses, or orthodontic appliances. 
• Candidates with parafunction or bruxism. 
• Candidates with systemic diseases or disabilities that may affect participation. 
• Drug-induced xerostomia. 
• Known allergy to resin-based composites or RMGIs. 
• Heavy smoking. 
• Pregnancy. 
• Lack of compliance. 
 
 
11. Proposed Intervention: 
Clinical examination: 
• For every patient, medical and dental history, caries risk assessment profile, and 
salivary flow test will be obtained. If bleeding on probing of the gingiva is positive, 
scaling will be performed at least 1 week before restoration. 
• Clinical examination will be done by mouth mirror, explorer, dentin hypersensitivity 
test using compressed air through triple syringe, and standardized photographs. 
 

11 
 
Restorative procedures: 
- 
Cavity preparation procedures for both the intervention and control groups: 
After giving local anesthesia, the operative field will be isolated using rubberdam by 
performing multiple teeth isolation with at least two teeth before and after tooth to be 
treated. Using a water-cooled high-speed handpiece (380.000-480.000 rpm), class V 
cavity will be prepared on the facial surface of the tooth using a pear-shaped diamond 
bur (MANI Ltd., Utsunomiya, Japan), and then a bevel is prepared 45ᴼ on the incisal 
wall of the cavity using a diamond finishing tapered bur (MANI Ltd., Utsunomiya, 
Japan). The bur will not be used for more than 3 cavity preparations. Any remaining 
soft carious dentin will be excavated by a small, sharp excavator (Dentsply® Maillefer, 
Switzerland). 
Intervention: 
Low Shrinkage, giomer paste-like resin composite (Beautifil™ II LS, Shofu Inc, 
Kyoto, Japan). 
All materials will be applied according to the manufacturer’s instructions. The 
prepared tooth surfaces will be rinsed and dried by gently blowing with an air syringe. 
Selective enamel etching will be done; where the enamel margins will only be etched with 
35-40% phosphoric acid gel for 10-15 seconds, rinsed for 5 seconds and gently dried. 
The unfilled universal adhesive (Shofu Inc, Kyoto, Japan) will be applied onto the 
entire cavity surface and left undisturbed for 10 seconds. Then the adhesive will be air 
dried with gentle air for 3 seconds and then, dried with stronger air to dry the surface. It 
will be light-cured using LED light-curing unit (Light output: 1200 mW/cm2) for 20 
seconds. Beautifil™ II LS will be applied according to manufacturer’s instructions as 
follows: shade selection will be done before rubberdam isolation. The material will be 
applied into the cavity using a gold-plated instrument, where incremental filling and 
light-curing of the material in layers, does not exceed 2 mm each. Each increment will 
be light-cured using LED light-curing unit (Light output: 1200 mW/cm2) for 20 
seconds. The restorations will be finished using water-cooled microfine diamond 
finishing burs for contouring and removal of excess restorative material and will be 
polished with aluminum oxide polisher immediately after filling. 
Comparator: 
Light-cured glass ionomer restorative, available in premeasured unit dose capsules (Fuji 
II LC®, GC Corporation, Tokyo, Japan). 
All materials will be applied according to the manufacturer’s instructions. The 
prepared tooth surfaces will be rinsed and dried by gently blowing with an air syringe. 
Cavity conditioner (GC Corporation, Tokyo, Japan) will be applied for 10 seconds, 
rinsed, and gently dried without dessication. GC Fuji II LC™ will be dispensed 
according to manufacturer’s instructions, followed by LED light curing (Light output: 
1200 mW/cm2) for 20 seconds. The restorations will be finished using water-cooled 

12 
 
microfine diamond finishing burs for contouring and removal of excess restorative 
material and will be polished. Then, G-COAT PLUS™ (GC Corporation, Tokyo, Japan) 
will be applied to finished restorations following manufacturer`s instructions. 
 
 
12. Outcomes 
Outcomes will be assessed by mouth mirror, dental explorer, standardized photographs and 
FDI probe according to modified USPHS criteria and Revised FDI criteria for direct and 
indirect restorations: 
• 
Primary outcomes: All restorations will be assessed for functional, biological, and 
aesthetic properties using Revised FDI criteria for direct and indirect restorations. 
They will be given a score (clinically excellent/very good, clinically good, clinically 
satisfactory, clinically unsatisfactory, clinically poor). 
 
• 
Secondary outcomes: Cost-Effectiveness Analysis 
Cost-effectiveness will be assessed by calculating the Incremental Cost-Effectiveness Ratio 
(ICER) and the Cost per Success Ratio (CPSR). These metrics will be used to compare the 
cost and clinical outcomes of LS-GRC and RMGI in treating class V cavities.  
 
Incremental Cost-Effectiveness Ratio (ICER) 
The ICER will be used to compare the cost-effectiveness of LS-GRC versus RMGI by 
evaluating the additional cost for each successful outcome provided by LS-GRC compared to 
RMGI. The ICER will be calculated using the following formula: 
𝐼𝐶𝐸𝑅=
(C₂−C₁)
(E₂−E₁)     
Where: 
• C2 and C1 are the total costs of LS-GRC and RMGI, respectively, 
• E2 and E1 are the respective effective outcomes (i.e., clinically excellent rates after 12 
months).  
The cost calculation methodology will account for several key factors, including the material 
cost per restoration, clinical application costs, and replacement or repair costs over time. 
Additionally, indirect costs, such as patient time, transportation, and the number of follow-up 
visits, will also be considered. 
 
Cost per Success Ratio (CPSR) 
The CPSR will be calculated to evaluate the cost per clinically successful restoration, 
determining the cost-effectiveness of each material in achieving successful outcomes, defined 
as restorations that will show no failure after 12 months. The CPSR will be calculated using 
the following formula: 
𝐶𝑃𝑆𝑅=
𝑇𝑜𝑡𝑎𝑙 𝐶𝑜𝑠𝑡
𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑆𝑢𝑐𝑐𝑒𝑠𝑠𝑒𝑠  
Where: 
• Total Cost refers to the overall cost per patient for each material, 

13 
 
• Number of Successes refers to the number of restorations that met the pre-defined 
criteria for clinical success (i.e., clinically excellent rate after 12 months). 
 
13. Participant timeline: 
 
-1 
T 
F2 
F3 
Activity 
Staff 
member 
1 month 
before 
intervention 
Intervention 
(Zero point) 
Follow up 
(6 
months) 
Follow up 
(12 months) 
Recruitment 
M.G. 
E.M. 
X 
 
 
 
Diagnosis 
M.G. 
X 
 
 
 
Consent 
M.G. 
X 
 
 
 
Baseline data 
collection 
M.G. 
X 
 
 
 
Cavity 
preparation  
M.G. 
 
X 
 
 
Randomization 
H.H 
 
X 
 
 
Application of 
interventions 
M.G. 
 
X 
 
 
Outcome 
assessment 
E.M. 
 
 
X 
X 
 
 
14. Sample size calculation: 
The sample size was calculated based on a previous study by Vural et al in 2021, in which 
percentage of successful class V restorations (Score A and B) using resin modified glass 
ionomer regarding marginal discoloration was 68.7%. By implementing a two tailed Z test 
for difference between two independent proportions with an alpha level of 5% and a power of 
80%. The minimum sample size needed was 23 per group in order to detect a difference of 
30%. Sample size was increased by 20% to compensate for possible dropouts to reach 28 
teeth per group. Sample size was performed using G*Power version 3.1.9.2 for windows. 
 
15. Patient Recruitment: 
Patients will be recruited by M.G. using stratified sampling method until reaching to the 
target sample size. They will be recruited from clinic of conservative dentistry department in 
Faculty of Dentistry, Cairo University, where there is a continuous and high patient flow 
from which eligible patients will be recruited to fulfill the eligibility criteria 1 month before 
intervention.  
 
 
 
 

14 
 
B)  Assignment of interventions: 
 
16. Allocation: 
16. a) Random sequence generation (Randomization): 
H.H. will perform simple randomization according to a check list, including the number of  
participants by generating numbers from 1 to 56, divided into two groups denoting with letter 
A and B. Randomization will be generated using (www.randomization.com).  
 
16. b) Allocation concealment mechanism:  
The allocation sequence will be kept with the contributor (E.M.) in sealed tight envelopes 
concealed from the primary investigator. The principal investigator (M.G.) will know the 
allocation of the consented participant just before starting the restorative procedures. 
 
16. c) Implementation 
All participants who fulfill eligibility criteria and who give consent for participation will be 
randomized by E.M. into two groups. 
 
17. Blinding (masking): 
Participants will be blinded to the intervention they were assigned too. Outcome assessors 
will be blinded as well as statisticians. The principal investigator cannot be blinded due to the 
difference in manipulation and application of restorative materials

15 
 
 
C) Data collection, management, and analysis: 
18. Data Collection methods: 
For every patient, medical and dental history and caries risk assessment profile will be 
obtained. The examination chart will be filled in by (M.G). M.G. will record telephone 
numbers and address of all subjects in the study as a part of the signed consent. M.G. will 
receive a phone call at the time of the pre-determined follow-up date.  
Patient retention:  
The patient's phone number will be recorded in their charts and before every visit the patient 
will receive a reminder call by (M.G. and E.M.). If the patient did not answer, another 
appointment will be scheduled within a week.  
 
19. Data management: 
All paper sheets that are concerned with the personal or outcome data will be stored in locked 
cabinet and in the computer at the Conservative department. The excel sheets of the patient’s 
data will be stored in the computer of the Conservative Department- Faculty of Oral and 
Dental Medicine. The computer will have a password only known to M.G. and D.K. to 
prevent unauthorized access to data and double data entry.  
 
20. Statistical analysis plan: 
a) Statistical Methods: 
Data will be analyzed using Medcalc software, version 19 for windows (MedCalc Software 
Ltd, Ostend, Belgium). Categorical data will be described as frequency and percentage. 
Intergroup comparisons between categorical variables will be performed using the chi square 
test, while intragroup comparisons within each intervention will be performed using 
Cochran's Q test followed by pairwise multiple comparisons. A p-value less than or equal to 
0.05 will be considered statistically significant and all tests will be two tailed. The statistical 
power of the study will be set at 80 % with 95 % confidence level. 
 
b) Primary and Secondary Outcomes: 
All outcomes will be assessed after 12 months; with follow up at baseline, 6, and 12 months. 
Prioritization of 
outcomes 
Outcome 
Measuring device 
Measuring unit 
Primary Outcome 
Functional, 
biological, and 
aesthetic 
properties. 
Revised FDI criteria for 
direct and indirect 
restorations (Hickel R, 
2022) 
Ordinal data 
(Scores) 
Secondary Outcomes Cost-Effectiveness 
Analysis 
Incremental Cost-
Effectiveness Ratio 
(ICER) and the Cost 
per Success Ratio 
(CPSR) 
Currency 

16 
 
 
c) Handing of missing data:  
All randomized participants will be included in the primary analysis according to the 
intention per protocol analysis. Participants who discontinue or are lost to follow-up will be 
analyzed in the groups to which they were originally assigned, regardless of adherence to the 
intervention. No imputation will be performed for missing outcome data unless otherwise 
specified. 
d) Interim analyses and stopping rules: 
The study will be designed to continue until the planned sample size was reached and all 
follow-up completed, with no provision for early stopping. The trial will be completed 
according to this original protocol without any interim evaluations or modifications. 
 
D) Data monitoring: 
21. Monitoring 
H.H. and D.K. will monitor this study, who will have full access to the results and will take 
the final decision to terminate the trial.  
22. Harms 
Operator M.G. should inform participants about the possible harms (pain, loss of restorations, 
leakage, and fracture of restoration). If present, participants should contact the operator at the 
moment through telephone. For assessment radiograph, inspection, percussion, and vitality 
tests are performed; the data should be reported to the main supervisor (H.H.) and managed 
through removal of the restorations and alleviation of pain. 
23. Audit 
In this trial auditing will be done by the main and co-supervisors (H.H. & D.K.) to assure 
quality of the research methods, restorative techniques, and interventions. 
 
IV. Ethics and dissemination 
24. Research ethics approval 
Application forms for accomplishing clinical trial, checklist and informed consent of 
Research Ethics Committee (REC) Faculty of Oral and Dental Medicine, Cairo University 
will be retrieved and filled, then will be delivered for REC committee for approval, this is 
done to prevent any ethical problems during the study or any harms for any of the 
participants. 
 
25. Protocol amendments 
If a new protocol is used a protocol amendment will be submitted, containing a copy of the 
new protocol and a brief explanation about the differences between it and the previous 
protocols. If there is a change in the existing protocol that affects safety of subjects, 
investigation scope, or scientific quality of the trial an amendment containing a brief 
explanation about the change must be submitted. If a new author is added to accomplish the 
study an amendment including the investigator’s data and qualifications to conduct the 
investigation will be submitted to prevent ghost authorship. 

17 
 
26. Informed consent 
M.G. is responsible for admitting and signing the informed consents during enrollment day. 
 
27. Confidentiality 
The name and the personal data of the participants will not appear on the protocol form and 
should be maintained secured for 10 years after the trial. This is done for protection of 
participants' privacy and civil rights. 
 
28. Declaration of interest 
There is no conflict of interest, no funding or material supply from any parties. 
 
29. Access to data 
Access to final data will be allowed to M.G. and the main and co-supervisors (H.H. & D.K.) 
of the study who are not involved in assessment of the outcome. 
 
30. Post-trial care 
Patients will be followed up after restoration to ensure oral hygiene measures. When there is 
any evidence of restoration failure, patients will be treated by immediate restoration removal 
and glass ionomer restoration will be placed. 
 
31. Dissemination policy 
Trial results will be available in the database department and a copy of the thesis will be 
available at the department library and at the official site of the Egyptian Universities 
Libraries Consortium. Final report of the trial will be also published in international journals. 
The trial will be further publicized via conferences, seminars and expert meetings in Egypt 
and abroad.  

18 
 
V. Appendices 
32. Informed consent 
 
الموافقه المستنيرة للمتطوعين 
 
:البحث البحث باللغة العربية عنوان 
 التقييم السريرى لمركب الراتنج ذات االنكماش المنخفض مقابل اسمنت االيونمر الزجاجى المعدل بالراتنج فى عالج
آفات التسوس العنقية: تجربة سريرية عشوائية 
الهدف من إجراء البحث :
 
 معرفة األداء السريري
ل حشوات الراتنج االمهجنة 
 ذات االنكماش المنخفض مقارنة باألداء السريري لحشوات 
 اسمنت االيونمر
 الزجاجى المعدل بالراتنج فى
عالج آفات التسوس .
 
 )العمل خطة( بالتفصيل المريض على  اجراؤه سيتم وما  عن مقدمة 
1.
 
 .الكشف على المرضى و تشخيصهم 
2.
 
 شرح خطة العمل و الهدف من البحث و اخذ الموافقة المستنيرة من المرضى المناسبين للتجربة و الموافقين على
 .الخوض في التجربة 
3.
 
 التوزيع العشوائي للمرضى على(  مجموعتي التجربة
حشوات الراتنج االمهجنة ذاتية اللصق( ) و 
 الحشوات للراتنج
 )المعتاد 
4.
 
 .عالج المرضى بالحشوات المستخدمة في التجربة بخطوات مطابقة لترشيحات و خطوات المصنع 
5.
 
 .تقييم الحشوات سريريا بإستخدام معايير الواليات المتحدة للصحة العامة المعدلة 
6.
 متابعة المرضى لتقييم أداء الحشوات عند ست شهور و بعد مرور عام 
 و عام و نصف 
 .ثم عامين 
 المتطوع  للشخص الفائدة المباشرة 
 عالج ضرسه المسوس بحشوة تطابق المعايير التكنولوجية الحديثة و التي من المتوقع ان تعطي أداءا سريريا جيدا وذلك خالل
 .زيارة واحدة فقط 
 البحث  من  المرجوة العامة  والفائدة العلميه الفائده 
 متابعة و تقييم األداء السريري ل
حشوات الراتنج ا المهجنة ذات االنكماش المنخفض
في حشو ا ألسنان
األمامية 
 خالل12
 
شهر.
 
 األعراض 
 الجانبية و درجة المخاطرو المتوقع حدوثها وكيفية 
 التعامل 
 معها 
 متوقع انها تكون قليلة الحدوث و هي حدوث كسر في الحشوة او تسوس ثانوي و سيتم التعامل معها بإعادة العالج مرةاخرى
 .بإستخدام حشوة كمبوزيت من نوع اّخرذات جودة عالية و مطابقة لمعايير العالج الحديثة 
 ]     [ أخرى               ] √    [ شرح شفهي           ]     [   قراءة      :المعرفه الكامله للمريض بخطوات البحث
     
1.
 
 لقد 
 اطلعت 
 بعناية وفهمت الغرض من إجراء 
 البحث وطبيعة 
 هذه الدراسة ، 
 وأنا أفهم ما هو ضروري إلنجاز هذه 
اإلجراءات.
 
2.
 قد 
 أعلمنى 
 الطبيب الباحث بالبدائل العالجية 
 الممكنة 
 لهذا البحث .
 
3.
 
 لقد أبلغنى الطبيب الباحث بجميع المخاطر المحتملة 
 لهذا 
 البحث  و كيفية 
 التعامل 
 معها.
 

19 
 
4.
 أوافق 
 على 
 التصوير 
 والتسجيل ، وجميع 
 أنواع 
 األشعة 
 والتي يتعين القيام 
 بها 
 فى 
 هذا الدراسة  ، 
 بشرط عدم الكشف 
 عن 
هويتي.
 
5.
 - 
 لقد قدمت تقريرا دقيقا 
 عن تاريخ 
 حالتى الصحية .وأبلغت الطبيب بجميع أنواع ردود األفعال 
 الصحية  
 أو الحساسية غير 
العادية من 
 األدوية أواألغذية 
 أولدغ 
 الحشرات أومواد 
 التخدير 
 أوالغبار أو 
 أى 
 ردود أفعال حدثت لى من 
 أى مواد أخرى  ، 
أونزيف 
 غير 
 طبيعي 
 أو أي 
 ظروف أخرى 
 ذات 
 صلة 
 على 
 صحتي 
 
6.
  أقر 
 بأننى 
 غير 
 مشترك فى أى 
 بحث 
 أخر 
 منذ بداية هذا البحث و حتى 
 إنتهائه  و أننى سأعلم الطبيب 
 الباحث لو دخلت 
 أى 
بحث أخر طوال 
 فترة 
 هذا 
 .البحث 
7.
 
 .أتعهد باعادة األجهزة (األدوات ) الطبية المستخدمه في البحث في حالة التوقف أو عند انتهاء البحث 
 
 
بعد  معرفة  المعلومات  المتاحة  الخاصة  بالبحث  يتفضل  الشخص  المتطوع  أو  المسئول  عنه باالختيار  بحرية  ما  
 بين 
االشتراك من 
.عدمه في حال الموافقة يتفضل بملء البيانات 
. الموضحة من حق المتطوع اإلنسحاب من البحث 
 بدون 
إبداء األسباب مع مراعاة حق إسترجاع الباحث ألى أجهزة 
 أو أدوات طبية مستعملة بغرض البحث بحوزة 
 المتطوع 
(تسمى من قبل 
 )الباحث 
 
 
 تعهد 
 الطبيب 
 المسئول 
 عن 
 البحث 
 بالحفاظ 
 على 
 سرية 
 المعلومات الخاصة 
 بالشخص المتطوع بالمشاركة 
 في 
 البحث مع ذكر الطرق
 )..المستخدمه لذلك مثل استبدال االسماء بارقام كوديه أو اخفاء معالم الوجه عند التصوير الفوتوغرافي ان امكن (الخ 
 
 من حق المتطوع االحتفاظ بنسخه مصورة من الموافقه
المستنيرة للبحث الذي تطوع فيه 
 
:اسم المتطوع                                                  
                            
   تاريخ الميالد :
 
 )الرقم القومي ( ان وجد 
  اسم ولي األمر أو 
                                                    :)المرافق(عند اللزوم:الرقم القومي  
:العنوان                                                                   
               
      الهاتف :
 
                                                                                                 
 :التاريخ 
 
توقيع 
 الباحث :
                                                                                                            
 التاريخ 
 .د منة عمر الغمراوى 
 .د دينا محمد كمال 
 الدين 
 .د هبة صالح الدين حمزة 
توقيع 
 المشرف على البحث (في حالة الرسائل):                                                                       التاريخ:
 
 بيانات تمأل بمعرفة اللجنة 
         هذا البحث تمت موافقة اللجنه عليه برقم 
 
 
 
 
 
 
 
 

20 
 
VI. Statement of originality 
33. Statement of originality 
The impact of cervical caries is bidirectional on both the tooth surface and 
periodontal tissues, increasing the impact of both diseases on a patient's oral health status. 
The ability to obtain a completely isolated field, gain proper access to the lesion, restore it 
while fulfilling the biological, esthetic, and mechanical properties should be considered. 
Thus, it will eliminate the financial burden for the community in return, through long 
standing restorations without the need for repair or replacement (AlQranei MS et al, 2021).   
 
 
 

21 
 
VII. References: 
 
• Algailani U, Alshaikhli LO, Al-Zahawi A, Alzbeede A, Diyya AS, Osman O. Comparing 
occlusal and cervical microleakage in class V restorations using two different nanohybrid 
resin composite with different insertion techniques. Materials Today: Proceedings. 2022 
Jan 1;60:1736-40. 
• AL-Gailani UF, Alqaysi SD. Estimation of the gingival microleakage of two composite 
resins with three insertion techniques for class V restorations (in-vitro comparative 
study). Sulaimani Dental Journal. 2019;6:15-21. 
• AlQranei MS, Balhaddad AA, Melo MA. The burden of root caries: Updated perspectives 
and advances on management strategies. Gerodontology. 2021 Jun;38(2):136-53. 
• Akarsu S, Atasoy S. Comparison of Microleakage in Class V Restorations Using 
Different Composite Resins and Techniques. Journal of Dental Materials & Techniques. 
2021 Oct 1;10(4). 
• Bheda RK, Mulay SA, Tandale AS. In vivo longevity of Giomer as compared to other 
adhesive restorative materials: A systematic review. Journal of the International Clinical 
Dental Research Organization. 2020 Jan 1;12(1):3-7. 
• da Silva AR, Feitosa VG, de Souza AN, Muniz RP, Ornellas MC, Silva EP, Braz R. 
Mechanical properties of composites with bioactive technology Giomer: a literature 
review. Research, Society and Development. 2021 Mar 21;10(3):e43310313413-. 
• Hickel R, Mesinger S, Opdam N, Loomans B, Frankenberger R, Cadenaro M, Burgess J, 
Peschke A, Heintze SD, Kühnisch J. Revised FDI criteria for evaluating direct and 
indirect dental restorations—recommendations for its clinical use, interpretation, and 
reporting. Clinical Oral Investigations. 2022 Dec 12:1-20. 
• Huang Y, Song B, Zhou X, Chen H, Wang H, Cheng L. Dental restorative materials for 
elderly populations. Polymers. 2021 Mar 8;13(5):828. 
• Inthihas SK, Nirmala SV, Rudhravarm VR. Clinical and radiographic success of three 
adhesive restorative materials in primary molar proximal lesions: A randomized clinical 
trial. Contemporary Clinical Dentistry. 2019 Jul;10(3):483-488. 
• Kim JH, Cho J, Lee Y, Cho BH. The survival of class V composite restorations and 
analysis of marginal discoloration. Operative dentistry. 2017;42(3):E93-101. 
• Koc Vural U, Kerimova L, Kiremitci A. Clinical comparison of a micro-hybride 
resinbased composite and resin modified glass ionomer in the treatment of cervical caries 
lesions: 36-month, split-mouth, randomized clinical trial. Odontology. 2021 Apr;109:376- 
84. 
• Komalsingsakul A, Srisatjaluk RL, Senawongse P. Effect of brushing on surface 
roughness, fluoride release, and biofilm formation with different tooth-colored materials. 
Journal of Dental Sciences. 2022 Jan 1;17(1):389-98. 
• Rusnac ME, Gasparik C, Irimie AI, Grecu AG, Mesaroş AŞ, Dudea D. Giomers in 
dentistry–at the boundary between dental composites and glass-ionomers. Medicine and 
pharmacy reports. 2019 Apr;92(2):123-128. 
• Tonprasong W, Inokoshi M, Shimizubata M, Yamamoto M, Hatano K, Minakuchi S. 

22 
 
Impact of direct restorative dental materials on surface root caries treatment. Evidence 
based and current materials development: A systematic review. Japanese Dental Science 
Review. 2022 Nov 1;58:13-30. 
• Toz-Akalin T, Öztürk-Bozkurt F, Kusdemir M, Özsoy A, Yüzbaşıoğlu E, Özcan M. 
Clinical Evaluation of Low-shrinkage Bioactive Material Giomer Versus Nanohybrid 
Resin Composite Restorations: A Two-year Prospective Controlled Clinical Trial. 
Operative Dentistry. 2023 Jan;48(1):10-20. 
• Zhang H, Wang L, Hua L, Guan R, Hou B. Randomized controlled clinical trial of a 
highly filled flowable composite in non-carious cervical lesions: 3-year results. Clinical 
Oral Investigations. 2021 Oct;25:5955-65.