Al-Rafidain Dental Journal

Aims: To evaluate the biocompatibility and osteogenic potential of calcium silicate-based cements (CSCs) modified with casein phosphopeptide – amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide – amorphous calcium fluoride phosphate (CPP-ACFP). Materials and method: Commercially available CSCs were modified with CPP-ACP or CPP-ACFP to prepare CPP-ACP and CPP-ACFP-modified Biodentine™ (0%, 0.5%, 4.0% w/w), Angelus® MTA (0%, 0.5%, 2.0% w/w) and NEX® MTA (0%, 0.5%, 3.0% w/w). For each group, 50 mg, 300 mg and 1500 mg of the cement mixed according to manufacturers’ instructions were placed and adapted at the bottom of 96 well, 24 well and 6 well (respectively) cell culture plates. After 24 h, the cement-coated plates were sterilised by ultraviolet light for 1 h. MG-63, MC3T3-E1, HGF-1, NIH3T3 cells were grown in the cement-coated plates and the cellular proliferation, cellular toxicity, alkaline phosphatase activity, cytokine production (interleukin-1α; IL-1α and interleukin-6; IL-6) and expression of mineralisation-associated proteins (collagen type 1, osteocalcin and osteopontin) were determined. Results: The addition of 0.5% CPP-ACP and 4.0% CPP-ACFP to Biodentine™, and 2.0% CPP-ACFP to Angelus® MTA significantly reduced the proliferation of MG-63. The addition of 4.0% CPP-ACP and 4.0% CPP-ACFP to Biodentine™, 2.0% CPP-ACFP to Angelus® MTA and 3.0% CPP-ACFP to NEX® MTA significantly reduced the proliferation of MC3T3-E1 cells. The tested cements, with and without CPP-ACP and CPP-ACFP, did not induce cellular toxicity nor IL-1α release. The addition of CPP-ACP and CPP-ACFP to Biodentine™ and NEX® MTA, and the addition of CPP-ACP to Angelus® MTA significantly increased the alkaline phosphatase activity of MG-63 cells. The presence of 4.0% CPP-ACP in Biodentine™, 0.5% and 2.0% CPP-ACP in Angelus® MTA, 0.5% CPP-ACFP in Angelus® MTA, and 0.5% CPP-ACFP in NEX® MTA significantly increased the alkaline phosphatase activity of MC3T3-E1 cells. All the tested cements significantly increased the release of IL-6 from MG-63 compared with negative control. The presence of CPP-ACP and CPP-ACFP in NEX® MTA significantly increased the release of IL-6 from MG-63 compared with unmodified NEX® MTA. MC3T3-E1 cells grown on Biodentine™ (unmodified and modified groups) and 3.0% CPP-ACFP-modified NEX® MTA released significantly higher IL-6 compared with negative control. 0.5% CPP-ACFP-modified Biodentine™ and 3.0% CPP-ACFP-modified NEX® MTA induced significantly higher IL-6 release from MC3T3-E1 compared with unmodified Biodentine™ and unmodified NEX® MTA respectively. The tested cements (especially Biodentine™, Angelus® MTA and CPP-ACFP-modified cements) induced the secretion of mineralisation-associated proteins (especially collagen type 1 and osteocalcin).Conclusions: The tested cements are biocompatible, and they could serve as a suitable scaffold which supports cellular proliferation. The addition of CPP-ACP and CPP-ACFP to CSCs improved the cements’ potential to induce osteoblastic differentiation.

Aims: To investigate the effects of the incorporation of hydroxyapatite nanoparticles (HA NPs) with size (20 nm) at two concentrations (0.5% and 1%) on the hardness of heat-cured acrylic resin. Materials and methods: The total number of specimens was thirty divided into ten specimens (control, 0.5 % HA NPs, and 1 % HA NPs), the hardness was performed using shore D (Durometer), FTIR test was performed using (BRUKER LASER CLASS 1). The statistical analysis was done by using the SPSS program including descriptive statistics, ANOVA, and Duncan's test at p ≤ 0.05. Results: The results demonstrated that there was a significant increase in the hardness for the PMMA-HA nanocomposite at HA nanoparticles (0.5%) and (1% when compared to the control. Conclusion: the use of hydroxyapatite nanoparticles as dental fillers at 0.5% and 1% by weight increased the hardness of PMMA denture base material.

Aims: To investigate the effects of the incorporation of hydroxyapatite nanoparticles (HA NPs) with size (20 nm) at two concentrations (0.5% and 1%) on the flexural strength and impact strength of heat-cured acrylic resin. Materials and methods: The total number of specimens was sixty which were divided into two groups, thirty specimens for each test (flexural strength test and impact strength test), ten specimens for each subgroup (control, 0.5 % HA NPs and 1 % HA NPs), the flexural strength was performed using the universal testing machine, and impact strength using Charpy impact tester. The statistical analysis was done by using the SPSS program including descriptive statistics, ANOVA, and Duncan's test at p ≤ 0.05. Results: The results demonstrated that there was a significant increase in the flexural and impact strength for the PMMA-HA nanocomposite at HA nanoparticles (0.5%) and (1%), when compared to control. Conclusion: the use of hydroxyapatite nanoparticles as dental fillers at 0.5% and 1% by weight enhanced the flexural strength and impact strength of PMMA denture base material.

Abstract
Aims: The study aimed to assess the tensile bond strength of modified-Heliosit orthodontic adhesive with different concentrations of seashell or zirconium oxide nanoparticles. Materials and methods: Thirty-five sound-extracted human premolars were collected. Hydroxyapatite nanoparticles were manually prepared from natural snail seashells. Heliosit orthodontic adhesive was modified by (8%, 10%, and 12% seashell), and (1%, 3%, and 5% zirconium oxide) nanoparticles. Standard edgewise brackets were bonded to buccal enamel surfaces of the samples of control and six modified adhesive groups. At 24 h after bonding, tensile bond strength was measured. The adhesive remnant index was scored under (10X) magnification power of the stereomicroscope after de-bonding. The chemical characteristics of orthodontic adhesive material were explored before and after mixing with seashell and zirconium oxide nanoparticles by using Fourier Transform Infrared Spectrometry. Results: Seashell groups (8, 10, & 12 %) containing hydroxyapatite nanoparticles and zirconium oxide nanoparticles groups (1%, 3%, and 5%) had a higher tensile bond strength mean value than the control group, (10%) seashell group had the highest mean value, while the least mean value was in the control group with statistically significant differences between them. Regarding the adhesive remnant index, no significant differences were found among the studying groups. Conclusions: the addition of (10%) seashell nanoparticles had the best performance and improved the tensile bond strength of Heliosit orthodontic adhesive without violating the remnant of adhesive on the buccal enamel surface after brackets de-bonding or inducing any chemical reactions with the resin adhesive.

Aims: To evaluate the effect of adding salinized zirconium oxide (ZrO2) and silicon oxide (SiO2) nanoparticles in two concentrations on the translucency of heat-cured denture base material. Materials and methods: Fifty discs (15×2.5mm) were prepared in accordioning to the manufacturer's instructions and divided into five groups, control without nanoparticles reinforcement, 1%ZrO2, 3%ZrO2, 1%SiO2 and 3%SiO2 NPs reinforcement. Translucency was measured using a colorimeter. Results: The result showed a highly significant (P ≤ 0.01) decrease in the translucency. The ZrO2 Np reinforced more reduced in translucency than the SiO2 Np reinforced group. The 3% by weight is more reduced than 1% by weight. Conclusions: Both nanoparticles reduced the translucency

Aims: The purpose of this study was to test different design parameters for ISFPD frameworks fabricated from fiber-reinforced composite and polyetheretherketone. Material and Methods: 12 different framework digital designs made using the AutoCAD program were sent to Autodesk Inventor 2023 for finite element analysis (FEA), these designs included 6 different connector designs according to cross-sectional shape and height-to-width ratio as follows: (ellipse3:2, ellipse 4:3, round, ellipse3:4, ellipse2:3 and triangular9:8) with 2 different connector cross-sectional areas (12mm2 and 16mm2) and were presented to the FEA program as two different materials (PEEK and FRC) to study stress distribution and displacement under 800N load. Stress and displacement values were used to determine the suitable framework material, connector cross-sectional area, and design. Results: FEA had resulted in FRC frameworks exhibiting higher resistance to bending than PEEK frameworks. 16mm2 connector cross-sectional area resulted in higher resistance to loading than 12mm2 connectors. Ellipse connectors with 3:2 height-to-width designs also resulted in the highest resistance to bending compared to other designs. Triangular designs resulted in the highest areas of stress concentration among other designs. Conclusions: Framework design should be considered to allow safe usage of PEEK and FRC as framework materials, FRC framework is more resistant to bending, and increasing the height of the connector increases the resistance to bending thus making ellipse designs with higher height-to-width ratio better in resistance to bending, triangular cross-section designs are not recommended.

Aims: The purpose of the current study is to compare the impact of three different treatment approaches on the surface microhardness of the enamel of third molar teeth. Materials and Methods: An in vitro study was done on fifty extracted impacted third molars. All samples were immersed in solutions of pH cycle for 10 days (demineralizing solution for 3 hours, remineralizing solution for 20 hours, and artificial saliva for 30 minutes twice daily). Then the samples were divided randomly into 5 groups according to enamel surface treatment, group1: Colgate (containing Arginine) toothpaste, group2: GC (containing Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-tooth mousse, group 3: Sensodyne (containing NovaMin) toothpaste group 4: distilled water and group 5: pH cycle solutions. The microhardness numbers were calculated from the length of the indentation on the enamel surface, the indentation length was determined microscopically with 70X magnification. An ANOVA was constructed (value P ≤ 0.05) followed by Duncan’s post –hoc test for comparisons of mean values. Results: there were significant differences among the study groups with respect to Vickers microhardness (VMH) mean values of samples. The lowest value was for the control group after the pH cycle followed by the Colgate (containing Arginine) group and the highest value was for the control group before the pH cycle followed by the Sensodyne (containing NovaMin) group. Conclusions: Sensodyne (containing NovaMin) toothpaste is more effective in restoring the hardness of artificial WSLs when compared with GC (containing CPP-ACP) and Colgate (containing Arginine) toothpaste

Aims: To compare the extraoral and intraoral scanners' accuracy in obtaining implant impressions using an in-vitro reference model. Materials and methods: An upper master model was fabricated with two parallel dental implants at the first and second premolars missing regions in size (4.0mm in diameter and 10mm in length); twenty impressions were made using the intraoral and extraoral scanners to produce twenty digital impressions (10 for each one), which will result in twenty digital casts. The linear distance measurements were performed using (Medit Design) digital measurement by using Medit Intraoral Scanner. Results: In the digital part there was a highly significant difference between measurements for the oral scanner (MeditI500) and extraoral scanner Rainbow using Medit design, the intra-oral scanner (MeditI500) is the highest value which is at a level of significance p≤0.01. Conclusion: The Medit I500 Intra Oral Scanner is a more accurate impression technique than the Rainbow extraoral scanner in transferring implant position

Aims: This study aimed to compare the accuracy of implant position transfer using three impression materials with two techniques. Materials and methods: A master model was fabricated with two parallel dental implants at the first and second premolars missing regions in size (4.0mm in diameter and 10mm in length); Two traditional impression techniques (open and closed tray); Three silicone impression materials were used which are condensation, Additional (heavy and low) and Additional (medium) consistencies. Sixty conventional impressions were taken, ten impressions for each material and each technique. The linear distance measurements were performed using two methods: Digital Vernier and Digital measurement by using Medit Intraoral Scanner. Results: The open tray technique showed significantly fewer changes (P≤ 0.05) with linear distance measurements when compared to the control, while the closed tray technique showed significantly more changes (P≤ 0.05) with linear distance measurements when compared to the control. In comparing Medit Design and digital vernier as methods of measurement for both open and closed tray techniques; there was no significant difference in the accuracy of measurements for both of these two methods of measurement at a level of (P≤ 0.05). Conclusion: The additional silicone material is the best in its accuracy in transferring implant position for (open and closed tray) conventional impression technique. The condensation silicone material is the worst in accuracy in transferring implant position for (open and closed tray) conventional impression technique. The open tray technique showed significantly more accuracy than the closed tray technique in transferring implant position in the traditional impression technique

Aims: To assess the effect of fiber reinforcement materials on the flexural strength of
heat-cured denture-based resin. Materials and Methods: A sample of heat-cured
acrylic resin was created and divided into a control group (heat-cured with no fiber
addition) and two experimental groups (with fiber additive). The flexural strength was
evaluated, and calculated, and the information was statistically analyzed using
descriptive statistics, an analysis of variance (ANOVA), and Duncan multiple range
tests with p ≤ 0.01 in SPSS Version 19. Results: The result showed a highly significant
increase in flexural strength, untreated polypropylene fibers showed the highest flexural
strength followed by untreated glass fibers. Conclusion: Reinforcement with fibers was
an efficient approach for the improvement of flexural strength of heat-cured PMMA
denture base resin

Aims: This study was carried out to evaluate the flexural strength of heat-polymerized
acrylic denture base material that is readily accessible commercially after
strengthening with two kinds of saline treatment fibers. Material and Methods:
Samples were created using traditional acrylic resin, the same resin that was
reinforced with glass and polypropylene fibers, and conventional acrylic resin alone .
A 3-point bending test was used to gauge the flexibility of the material, and the
findings were then examined using a one-way analysis of variance Results: The
flexural strength of all strengthened samples was greater compared to that of standard
acrylic resin; those reinforced with polypropylene fibers had the highest flexural
strength, followed by those reinforced with glass fibers. Conclusion: Heatpolymerized
PMMA denture resin's flexural strength was increased following
reinforcing with treated glass or polypropylene fibers, within the confines of the fibers
used in this study. These findings might be used as the bases of distal extension partial
dentures and temporary fixed partial dentures

Aims: to measure the shear bonding strength of self-adhesive resin-cement bonded to lithium disilicate glassceramic
with different surface treatments and compare it with that of conventional resin-cement. Materials
and Methods: eighty circular blocks (10mm-diameter x 3.0mm-thickness) of IPS e-max Press ceramic, were
fabricated in accordance with the manufacturer’s instructions. The samples were divided into four main groups
(n=20) according to surface treatments: group A no surface treatment, group B sandblasting with 50-μm
alumina particles for five seconds under two bars of pressure using a sandblasting device, group C acid-etching
with 9% hydrofluoric acid for 20-seconds, followed by rinsing with distilled water, group D combination by
sandblasting with 50-μm alumina particles as in group B and then were etched with 9% hydrofluoric acid as
in group C. For the bonding procedure, each main group was divided into two subgroups (n=10) according to
the types of resin cement that were used: sub-group1: specimens were prepared by applying one layer of silane
on the ceramic surface. The single bond universal was applied by micro-brush. Then specimens were light
cured, next, 2-mm-long transparent plastic tubes with 4-mm diameter were placed on the ceramic surface, and
filled with conventional resin-cement, it was light-cured, sub-group2: 2-mm-long transparent plastic tubes
with 4-mm diameter were placed on the ceramic surface and filled with self-adhesive resin-cement, then were
light-cured, and the shear bond strength was tested using the universal testing machine. The results were
analyzed statistically. Results: Comparisons of shear bonding strength between total conventional and selfadhesive
groups show that the highest mean was in the conventional adhesive group (49.13 ±3.05), while the
lowest mean was in the self-adhesive group (26.51 ±2.16). Conclusions: With all surface treatments, selfadhesive
resin-cement had a lower mean shear bond strength than conventional resin-cement

Aims: The aims of the current study were to investigated and compared the effects of different
concentrations of Thymus vulgaris and Lavandula angustifolia essential oils incorporated in orthodontic
adhesive on compressive strength. Materials and Methods: Thirty samples were prepared to be included
in the study groups. They were constructed from cylinders of 6 mm in height and 4 mm in diameter for each
one. The adhesive samples were modified by incorporating 1%, 3% of Thymus vulgaris and 1%, 3%
Lavandula angustifolia essential oils separately. After curing of the modified adhesive, each sample was
placed in a universal testing machine between its plate and arm that has a capacity of 1000 kN. The
compressive strength was tested by using a crosshead speed of 0.5 mm/min. The force of the machine was
delivered perpendicularly to the composite samples by a plate producing a compressive force on the sample.
The applied force at fracture time was recorded in Newton, then it was converted into mega Pascal (MP) by
dividing the applied force by the surface area of the composite samples. The data were statistically analysed
at p <0.05. Results: The results revealed that 1% Lavandula angustifolia group showed the highest mean
values of compressive strength among the groups except for the control. Whereas, Thymus vulgaris groups
showed the lowest mean values of compressive strength. The remaining groups were distributed on statistical
levels between the highest and lowest levels of mean value. One way analysis of variance demonstrated a
significant difference within and between the mean values. Multiple comparisons showed a significant
difference in compressive strength between control and of 3% Thymus vulgaris groups at (p < 0.05).
Conclusions: Compressive strength recorded similar reduction behaviour for the two materials regarding
the reduction in its value. However, the incorporation of 3% Thymus vulgaris showed evident decrease

Aims: The current study aimed to compare implant stability and bone density using a
Concentrated Growth Factor placed before implant placement in the iliac crest of sheep.
Materials and Methods: Four healthy local breed male sheep were enrolled in the study. All
sheep served as two observation subgroups. The iliac crest of both sides of each sheep was
operated on a random basis at one- and three-months intervals. Before each surgery, two 10 ml
blood samples were drawn and immediately centrifuged in a specific centrifuge. After a cycle,
the membrane was shredded into small pieces to be placed inside the surgical site before implant
installation. Five standard osteotomy sites were created for the placement of five dental implants,
two served as a control in which the implant was installed without additives. The other three
osteotomy beds served as study groups in which shredded pieces of Sacco’s membrane were
placed before implant installation. Following implant installation, dental implant stability using
the Osstell Beacon device was recorded. Following animal sacrifice, bone specimens were
retrieved and secondary implant stability and bone density around dental implants using
Computed Tomography and Cone Beam Computed Tomography scans were measured
representing one- and three-months intervals. Results: For dental implant stability, the results
showed no significant differences at one-month intervals between both groups yet a statistically
significant difference was disclosed at 3 months favouring the tested group. Conclusions:
Within the limits of this study, it is possible to conclude that the application of CGF to the socket
walls before the placement of implants may enhance the healing of bone surrounding implants,
accelerate osseointegration, and offer a choice that is both convenient and affordable for implant
placement

Aims: to distinguish if the nanodrolone decanoate has any effect on the healing of facial muscular wounds
which are one of the issues that dentists face, and it is a challenge to find a useful treatment for this condition.
This study explores the idea that, when used in conjunction with surgical repair. The steroid Nandrolone-
Decanoate, when injected locally to the masseter muscle, improves healing. Materials and Methods: The
study comprised twenty-five healthy rabbits, were sorted into three equal groups at random. The animals were
classified randomly into 3 groups (5 rabbits/group). Group I: (control negative/5 rabbits) the rabbits were not
undergoing surgical procedure and not receive any treatment. Group II: (control positive/10 rabbits) the rabbits
were undergoing surgical procedure and receive distilled water injection. Group IIA: contained 5 rabbits that
were euthanized on the 3rd day of the surgical procedure. Group IIB: contained 5 rabbits that were euthanized
on the 7th day of the surgical procedure. Group III: (treatment/10 rabbits) the rabbits were undergoing surgical
procedure, and each rabbit, treated once daily with nanodrolone deconate (10 mg/kg) using Mantoux syringe
via intramuscular injection from the first day of the surgical procedure to the euthanizing day. Group IIIA:
contained 5 rabbits that were euthanized on the 3rd day of the surgical procedure. Group IIIB: contained 5
rabbits that were euthanized on the 7th day of the surgical procedure. Results: There are highly significant
differences in the serum aspartate aminotransferase (GOT) and Alanine aminotransferase (GPT). The results
demonstrate an increase (both enzymes) in the treatment group on the seventh day of the trial as compared to
the control group and the 3rd day. There is a decrease in the LDH (lactate dehydrogenase) level in the 7th day
of the treatment as compared with 3rd day of treatment group and with the control group. C –reactive protein
(CRP) serum results show a highly significant decrease in its level in 7th day as compared to the 3rd day and the
control group. Conclusions: Nanodrolone Decanoate may be used as an adjunctive therapy in the healing of
intramuscular wounds

Permanent teeth with incomplete root formation subjected to pulp exposure due to caries or
trauma, this cause interruption of root development and leave it with an open apex. Apexogenesis
aims to preserve teeth vitality while allowing complete root formation and apical closure. Many
materials had been used for this. This review article was conducted to highlight the indications,
advantages, and limitations of different materials used for apexogenesis

Aims: The present study aims to investigate the effect of insulin on the healing of dental sockets in diabetic
rabbits. Evaluating oral mucosa healing and bone regeneration of the healing process during three intervals 3-,
10- and 30-days post-extraction. Materials and Methods: Twelve male albino diabetic rabbits were used in
this study, these were randomly sub-divided into three sub-groups (N=4) for the histological and
immunohistochemistry evaluation at 3, 10, 30 days post-extraction and compared to the controls. The rabbits
were euthanized at the corresponding time interval, each rabbit represented a control and treated sample.
Bilateral maxillary first premolar extraction (treated side and control side) was performed, followed by
treatment injection into the socket. A gel foam cylindrical insert of (3*5 mm) dimensions was placed in both
sockets. For the treated groups; a standardized dose 10 IU in 0.1 ml from a solution of 100 IU/ml concentration
of Insulin; for each corresponding group was injected into the gel foam whilst in the socket of the treated side,
while for the control side (was kept plain without injection). A secondary post-extraction standardized dose was
split equally and injected buccally and palataly around the gingival margins of the studied socket on the 2nd,
4th, and 6th day post-extraction only for the treated side. For each study interval, rabbits in each group were
euthanized, then specimens from the oral mucosa and maxillary alveolar bone from the extraction sockets with
sufficient margins were immediately harvested and arranged for laboratory examination. Assessment of
inflammatory response, granulation tissue formation, re-epithelialization, and bone healing and the expression
of CD34 and Ki67 was performed. Non-parametric statistical analysis was performed, and significance was
recorded at p≤0.05. Results: Histological evaluation results revealed a significantly reduced inflammation
response, reduced granulation tissue formation, higher and quicker re-epithelialization and enhanced bone
formation for treated group when compared to control at certain time intervals within the total period of the
study. The immunohistochemistry results revealed a significantly increased expression of CD34 and Ki67
markers in the treated group as compared to the control groups at certain study intervals. Conclusions: Within
the limits of the present study, local application of Insulin demonstrated a positive effect on the healing process
of oral mucosa as well as bone regeneration of the dental socket of diabetic rabbits. The local injection of Insulin
would be suitable candidate to be used in the enhancement of post-extraction healing

Aims: This study aimed to evaluate the effect of different tapers (4% and 6%) on the cyclic fatigue
resistance of the 2Shape endodontic system using three types of canal curvature 45°,60°, and 90°.
Materials and Methods: This research used Sixty (60) NiTi rotary files. Two sets of these files were
created. (n = 30 for each group), group one TS1 (0.25) taper 4%, group two TS2 (0.25) taper 6%. Then,
each group was subdivided into three subgroups (n = 10 for each subgroup) each subgroup was tested in
45°, 60° and 90° canal curvature respectively in a stainless-steel metal block containing an artificial canal
with a radius of curvature of 3mm and diameter of 1.5 mm. Each file was rotated continuously at 300 rpm
and 1.2 N.cm torque for TS1, 300 rpm, and 2.5 N.cm for TS2 until it fractured. The time it took to separate
the files was noted. Each file's number of cycles to failure (NCF) was computed. Kolmogorov-Smirnova
normality test was done for all instruments and One-way ANOVA was used to examine the data
statistically. Results: At 45º canal curvature there is a highly significant difference between 2Shape taper
4% and 2Shape taper 6% (p ≤ 0.01). Regarding canal curvature of 60º there is a highly significant difference
between 2Shape taper 4% and 2Shape taper 6% (p ≤ 0.01). For canal curvature of 90 º there is a highly
significant difference between 2Shape taper 4% and 2Shape taper 6% (p ≤ 0.01). Conclusions: This study
concluded that the 2Shape system resists cyclic fatigue better at canal curvature of 45° followed by 60° and
90°. Regarding the taper used 4% is better than 6%. To limit the possibility of separation, it is advised that
these files be used just once

Aims: Natural products are used in dentistry to treat various dental diseases. They are considered an active alternative to antibiotics and could offer prevention and therapeutic approaches for oral infections. The main objective was to study the available information regarding the applications of natural products in orthodontics. Materials and Methods: We defined the natural products, and reviewed and explained their applications in general dentistry and orthodontics. Conclusions: This literature shows that several herbal products can control many inflammatory processes and are safer for longer than those chemical drugs.

Aims: to assess the effects of gaseous ozone and microwave exposure (as a positive control) on surface hardness and surface roughness of heat cure acrylic resin. Materials and Methods: A total of 60 samples of heat-cured acrylic resin were prepared, and divided into three subgroups, control, microwave radiation (positive control), and gaseous ozone. Surface hardness and surface roughness were evaluated. At a level of significance of 5%, data were assessed using one-way ANOVA and Tukey’s post hoc test. Results: Surface hardness and roughness were significantly different among groups. (p <0.001). Significant differences were identified by the post hoc test between all multiple groups (p <0.001). Conclusions: It is possible to conclude that gaseous ozone exposure improves the surface hardness of heat-cure acrylic resin.