Provisional Restorative Materials Research Articles

Heat treatment during setting on properties of resin-based provisional-restorative materials

This journal suppl. entitled: Abstracts of the Academy of Dental Materials Annual Meeting, 8-11 October 2014 - Bologna, Italy

Shear bond strength of four different repair materials applied to bis-acryl resin provisional materials measured 10 minutes, one hour, and two days after bonding.

This study investigated the shear bond strength of repaired provisional restoration materials 1) to compare the bond strengths between bis-acryl resin and four different materials and 2) to investigate the effect of the amount of time elapsed after bonding on the bond strength. The self-cured bis-acryl resin (Luxatemp) was used as the base material, and four different types of resins (Luxatemp, Protemp, Z350 flowable, and Z350) were used as the repair materials. Specimens were divided into three groups depending on the point of time of shear bond strength measurement: 10 minutes, one hour, and 48 hours. Shear bond strengths were measured with a universal testing machine, and the fracture surface was examined with a video measuring system. Two-way analysis of variance revealed that the repair materials (p<0.001) and the amount of time elapsed after bonding (p<0.001) significantly affected the repair strength. All of the repaired materials showed increasing bond strength with longer storage time. The highest bond strength and cohesive failure were observed for bonding between Luxatemp base and Luxatemp at 48 hours after bonding.

Effect of Aging Treatment on the Flexural Properties of Polymer Provisional Restoration Materials

본 연구는 고등학생의 진로개발역량에 있어 부모의 영향을 살펴보고자 하였다. 구체적으로 부모의 역할은 자녀가 지각한 흥미와 적성, 미래직업, 학교 및 학과 선택에 관한 부모와의 대화 정도, 부모의 자녀 희망직업 인지 여부, 부모의 학교 진로교육 참여, 부모의 학교 진로상담 만족도를 포함하였다. 고등학생 자녀의 진로개발역량은 개인영역, 사회영역, 진로관리영역으로 나누어 살펴보았다. 연구목적을 위해 교육부와 한국직업능력개발원이 실시한 “2016년 진로교육 현황조사” 자료로부터 부모와 자녀 모두 조사에 참여한 고등학생 5,841명의 진로활동 및 진로정보 관련 자료들을 사용하였다. 주요 결과는 다음과 같다. 첫째, 고등학생 자녀가 지각한 부모와의 대화정도는 흥미와 적성 또는 학교 및 학과 선택에 관한 주제인 경우 자녀의 개인영역, 사회영역, 진로관리영역 진로개발역량에 유의한 정적 영향을 미치고 있었다. 또한, 부모의 자녀 희망직업 인지여부가 고등학생의 진로개발역량에 긍정적인 영향을 주고 있었다. 둘째, 부모가 학교 진로교육에 참여한 자녀가 참여하지 않은 부모의 자녀보다 개인영역, 사회영역, 진로관리영역의 진로개발역량이 더 높은 것으로 나타났으며, 부모의 학교 진로상담만족도가 높을수록 세 영역에 있어 자녀의 진로개발역량이 향상되었다. 이 결과는 고등학생 진로개발역량에 있어서 부모 역할의 중요성을 보여주었으며, 이에 부모와 자녀 간에 진로에 대한 대화를 통해 경험을 공유하는 것이 필요하며, 학교 진로교육에 대해 부모가 자녀의 입장에서 관심을 가지도록 격려하는 것이 요구된다.

Intrapulpal thermal changes during direct provisionalization using various autopolymerizing resins: Ex-vivo study

BackgroundResin materials used in the fabrication of direct provisional restoration exhibit an exothermic reaction and the extent of damage may also depend on the remaining dentine thickness. An ex-vivo study was envisaged to compare the time related temperature changes in the pulp chamber during the fabrication of fixed partial denture provisional restorations using direct technique. The effect of differently prepared teeth (with varying remaining dentine thickness) on the above mentioned temperature changes were also evaluated. MethodsThermal changes were calculated in pulp chamber of three differently prepared tooth having different amount of remaining dentinal thickness (45 samples) and control with no tooth media (15 samples), using three different types of autopolymerizing provisional restorative materials using Cr/Al thermocouple connected to digital thermometer. ResultsThe data for the mean peak temperature rise was subjected to one way ANOVA analysis for relative comparison among subgroups within each main group and across the main groups. The results showed a statistically significant difference across both the subgroups and the main groups (p < 0.001). Then Turkey HSD test was applied to determine the significance of statistical difference between the means, within the groups. The differences in temperature rise were statistically significant for the three resins (p < 0.001). ConclusionPolymethylmethacrylate (DPI) showed the highest temperature rise value followed by polyethyl methacrylate (Tempron) and Bis-acrylate composite (CoolTemp). The maximum temperature rise was found on molar full veneer preparation followed by molar three quarter preparation and premolar three quarter preparation. Data and results from current study may assist clinicians to select an autopolymerizing provisional restorative resin when employing direct technique of fabricating provisional restorations for a specific tooth preparation which would cause minimal thermal trauma to pulpal tissue.

Evaluation of Colour Stability of Provisional Restorative Materials Exposed to Different Mouth Rinses at Varying Time Intervals: An In Vitro Study

The most important factor affecting esthetics is colour. Whether a definitive prosthesis or a provisional restoration, maintenance of esthetics is of prime concern along with restoration of function. Colour stability of provisional prosthesis is affected by various factors and various studies are documented in the literature on this. The purpose of this study was to evaluate the colour stability of provisional restorative materials exposed to different mouth rinses at varying time intervals. 120 discs, each of self cure tooth moulding material, Protemp 4 and Revotek LC were prepared and immersed in two mouth rinses, hexidine and periogard and evaluated for their colour stability after 1week, 1 and 3months. The data obtained was statistically analysed using ANOVA and Tukey's post hoc analysis. The results indicate that there is a significant difference in the colour variation of various materials in two different mouth rinses at different time intervals. Revotek LC was found to be the most colour stable material and periogard had the least staining potential at varying time intervals.

Microleakage of different provisionalization techniques for class I inlays

Background/purposeTo investigate the effects of different provisionalization methods on the microleakage of class I inlay cavities. Materials and methodsClass I inlay cavities were prepared on human molars (n = 60). Teeth were divided into six groups (n = 10). In the first group (ST-C), Structur 2SC (ST) was used with a provisional luting agent, and in the second group (SY-C), Systemp Inlay (SY) was directly applied and light-polymerized. In the remaining four groups, cavities in the third (SB-ST) and fourth (OS-ST) groups were, respectively, pretreated with the bonding agents, Single Bond (SB) and One Step Plus (OS), and the fifth (SB-SY) and sixth (OS-SY) groups were pretreated with the same bonding agents. The third and fourth groups were then restored with ST and the fifth and sixth groups with SY. The teeth were subjected to thermal cycling and immersed in a 0.5% basic fuchsin solution for 24 hours. Specimens were sectioned and examined for leakage. Data were analyzed using the Kruskal–Wallis and Mann–Whitney U tests (P < 0.01). The interface between the provisional material and dentin was observed using a scanning electron microscope (SEM). ResultsGroups treated with a bonding agent (SB-SY and OS-SY) before placement of the light-polymerized provisional material had significantly less microleakage (P < 0.01). No statistical differences were found between leakage scores of the remaining groups. The OS-SY group displayed the best cavity wall-inlay adaptation under SEM. ConclusionThe microleakage in class I inlay cavities could be reduced by the application of dentin-bonding agents after cavity preparation followed by the placement of light-polymerized provisional restorative materials.

An In Vitro Evaluation of Flexural Strength of Two Provisional Restorative Materials Light Polymerised Resin And Autopolymerised Resin.

Statement of problem: Flexural strength is important in determining the strength of interim restorations and it is especially important in long span and long term interim restorations. Studies comparing the flexural strength of provisional restorative materials are limited and inconclusive. Aim: To compare the flexural strength of provisional restorative material fabricated using light polymerized composite resin, Urethane dimethacrylate (UDMA) and auto polymerized resin, Poly Methyl Methacrylate (PMMA) Materials And Methods: This study included 40 specimens. Twenty bar-shaped specimens were fabricated for each group Polymethyl Methacrylate (PMMA), and Urethane dimethacrylate (UDMA) with the use of a split machined metal mold. These specimens were stored in artificial saliva for 10 days. Flexural strength was calculated using three point bending test under universal testing machine. Data were analysed using student-ttest (α=0.05) @ 90% power. Results: The mean flexural strength of provisional restorative specimen fabricated using Poly Methyl Methacrylate (PMMA-134.1 Mpa) was significantly higher than Flexural strength of provisional restorative specimen fabricated using urethane dimethacrylate (UDMA-107.8 Mpa). Conclusion: Within the limitations of this study by analyzing the results, it was concluded that the flexural strength of polymethyl methacrylate (PMMA) is comparatively better than the flexural strength of Urethane dimethacrylate (UDMA). PMMA could be a better provisional restorative material for an extended period, when the patient exhibits parafunctional habits, or when long-span prosthesis is planned.

A comparative analysis of staining characteristics of mouthrinses on provisional acrylic resin: An in vitro study

Aim and Objective: Provisionalization is essential for tooth protection and treatment outcome evaluation. Utmost care should be taken to maintain the soft tissue health when provisionals are cemented. Mouthrinses are commonly used as an adjunct to protect against caries and periodontal diseases. Thesesolutions are responsible for discolouration of provisional materials. In the present study, the aim is to assess the staining potentials of a chlorhexidine gluconate rinse, a benzydamine hydrochloride rinse and a tea tree oil rinse on a provisional acrylic material in vitro by application of a digital system for colour analysis Materials and Method: In this study, the staining potentials of a tea tree oil, a chlorhexidine gluconate rinse, and a benzydamine hydrochloride rinse was investigated; whereas distilled water was used as the control. Results: Color change of a commercially available provisional restorative material was evaluated after 24 hours immersion in three different mouthrinses. ∆E values obtained were 1.76 for chlorhexidine gluconate, 1.55 for benzydamine hydrochloride and 1.88 for TTO. Conclusion: Within the limitations of the current study, it is concluded that benzydamine hydrochloride exerts the least perceptible change in colour of bisacryl composite provisional resin material. Clinical Relevance to Interdisciplinary Dentistry Dentistry today is vastly different from what it was before. Today it is in the era of interdisciplinary approach from independent to interdependent. It is more result oriented and more successful when any case or situation is handled combined by interdisciplinary experts. Action and role of mouthrinses and their interdisciplinary outcome is evaluated in the present study.

Abutment selection, designing, and its influence on the emergence profile: A comprehensive review

The implant evolution has become a restorative driven field, and it is therefore important to know the designing principles of abutments and its connection to the implants and its rationale for use in clinical practice. The key is to have an optimum selection and designing of the implant to meet the implant position and angulation in the clinical scenario. A search was conducted both manually and electronically to find terms that included dental implants, dental abutments, custom abutments, cast abutments, abutment-implant interface, emergence profile, soft tissue profile, provisional restoration, CAD/CAM abutments, abutment innovations, abutment designing, abutment selection, and abutment materials. A total of 4332 English titles were obtained in various combinations and were repeated and duplicated due to multiple searching. Proper short-listing of the articles was done and a comprehensive review was formulated. This review article highlights various methods and rationale behind selection, designing of various abutments, its influence on emergence profile, and the newer advances and trends that have emerged in the field of implant dentistry.

The Effect of Glass and Polyethylene Fiber Reinforcement on Flexural Strength of Provisional Restorative Resins: An In Vitro Study

The aim is to evaluate and compare the flexural strength of different provisional restorative materials reinforced with glass and polyethylene fibers. A total of 90 samples were prepared and divided into three groups based on the type of fiber reinforcement, unidirectional S-glass (Splint-It) and ultra-molecular weight polyethylene (Ribbond). Unreinforced samples served as control group. Again each group was subdivided into three subgroups based on type of provisional restorative resins, heats cure polymethyl methacrylate, self-cure poly methyl methacrylate and self-cure bis-acryl composite. Samples were loaded in a universal testing machine until fracture occurs. The mean flexural strengths (MPa) were subjected to the one-way ANOVA, followed by the Tukey-HSD test at a significance level of 0.001. The result shows all the fiber reinforced samples possessed greater strength than the control samples. In control samples, the heat cure poly methyl methacrylate resin (72.74±2.28MPa) had the greatest flexural strength, followed by self-cure bis-acryl composite (67.05±2.35MPa) and self-cure poly methyl methacrylate resin (52.88±1.90MPa). In both heat and self-cure poly methyl methacrylate resin, the polyethylene fiber reinforcement (96.00±2.63MPa, 86.17±1.92MPa) provides the greatest strength than glass fiber reinforcement (92.68±1.58MPa, 76.40±2.11MPa). In self-cure bis-acryl composite, the glass fiber (105.95±3.07MPa) shows better reinforcement than polyethylene fiber (99.41±1.74MPa).The fibers reinforcement increases the flexural strength of provisional restorative resins.

In vitro color stability of provisional restorative materials

Discoloration of provisional restorations can result in esthetic problems which are critically important in, for example, anterior areas and may compromise the acceptability of the restoration. The purpose of this study was to investigate the effect of tea on provisional restorative materials. This study was designed to measure the degree of color change of three acrylic resin provisional materials, before and after immersion in artificial saliva and artificial saliva-tea solution for 2 and 4 weeks. Three types of acrylic provisional materials (duralay, tempron, acropars TRP), were studied. Twenty disks (20 ± 0.1 mm by 2 ± 0.05 mm) were fabricated from each material. Specimens were polished with acrylic bur using pumice and diamond polishing paste. Base line color was measured using a spectrophotometer. Ten disks were stored in artificial saliva and 10 were stored in a solution of artificial saliva and tea at room temperature. Color measurements were made after 2 and 4 weeks of immersion. Differences in color changes were compared by two way ANOVA, across the six groups, followed by a Turkey-Kramer's multiple comparison test. For specimens immersed in artificial saliva, the color change of methyl methacrylate materials; duralay (ΔE=4.94) and tempron (ΔE=6.54), was significantly more than butyl methacrylate material; acropars (ΔE=4.10). After immersion in an artificial saliva- tea solution, tempron exhibited less color change (ΔE=8.50) compared to duralay (ΔE=10.93) and acropars (ΔE=15.64). Color stability of methyl methacrylate is higher than butyl methacrylates so if provisional materials are used for extended periods of time; tempron is preferred.

A Comparative Evaluation of Temperature Changes in the Pulpal Chamber during Direct Fabrication of Provisional Restorations: An In Vitro Study

To compare the temperature changes in the pulpal chamber during fabrication of provisional restorations by direct method. A total of 108 three-unit FPD provisional restorations were fabricated on a study model and divided into three main groups according to the material used for the fabrication of matrix. Group A-Alginate impression index group, Group B-Polyvinylsiloxane putty impression index group, Group C-Vacuum formed template group. Each group comprising of 36 specimens, was subdivided into three subgroups based on the provisional restorative material used: polymethylmethacrylate (subgroup 1), polyethylmethacrylate (subgroup 2), bis-acryl composite resin (subgroup 3). Intrapulpal temperature changes were observed with the help of a thermocouple probe (connected to a digital microprocessor thermometer) inserted into the pulp chamber of an extracted mandibular second molar mounted on a study model, during the fabrication of provisional restorations by direct method. The subgroups mean temperature rise observed in Group A-A1, A2, A3 was 2.6250±0.2491, 1.0500±0.1382, 0.4083±0.1165, respectively. The subgroups mean temperature rise observed in Group B-B1, B2, B3 was 4.6250±0.2454, 3.3750±0.3415, 2.5917±0.2678, respectively. The subgroups mean temperature rise observed in Group C-C1, C2, C3 was 4.7694±1.8361, 3.0611±1.5767, 2.3806±1.5713, respectively. The observations were statistically significant. The intrapulpal temperature rise during fabrication of a provisional restoration depended both on the type of provisional restorative material and the type of matrix used. The clinician should choose carefully the resin and the matrix material while fabricating provisional restorations with direct method.

Evaluation of the effect of various beverages and food material on the color stability of provisional materials - An in vitro study

Aim:This study evaluated the color stability of four provisional materials: 1) Poly-methyl methacrylates (DPI); 2) Bis-acryl composite (ProtempTM II – 3M ESPE); 3) Bis-acryl composite (Systemp® c and b – Ivoclar Vivadent) and 4) Light polymerized composite resin (Revotek LC- GC).Materials and Methods:The color and color difference of each specimen after immersion in different staining solutions i.e. 1) tea and artificial saliva, 2) coffee and artificial saliva, 3) Pepsi and artificial saliva, 4) turmeric solution and artificial saliva was measured using reflectance spectrophotometer with CIELAB system before immersion and after immersion at 2, 5 ,7 , 10 and 15 days.Results:Revotek LC- GC (light polymerized composite resin) was found to be the most color stable provisional restorative material followed by Protemp II (Bis-acryl composite), Systemp (Bis-acryl composite) and DPI (Methylmethacrylate resin). Turmeric solution had the maximum staining potential followed by coffee, tea and Pepsi.

Multifactorial analysis of variables influencing the fracture strength of repair joints for provisional restorative materials using the statistically based Taguchi method

Background/purpose In this study, we investigated the relative contributions of design factors to the fracture strength of provisional materials after repair. Materials and methods The Taguchi method was used to investigate the optimal design with respect to four different design factors: subject material, repair material, repair design, and connector thickness. Each factor was assigned three levels. Using the Taguchi L 9 orthogonal array, nine rectangular bar-shaped experimental specimens with different parameter combinations were fabricated ( n = 5) and tested with a three-point bending test. The fracture load (in newtons) of each specimen group was recorded. The Taguchi method was employed to identify the significance of each design factor in controlling the fracture strength. The sensitivity of each design parameter was determined using an analysis of variance. Fractographic analysis was performed to identify the adhesive or cohesive failure mode for each specimen. Results The mean effect of the design factors at each level was determined. The subject material, with a contribution percentage of as high as 33.48%, had the most dominant effect on the fracture strength of the repaired provisional restorations, followed by the repair material (31.88%), connector thickness (19.70%), and joint design (14.94%). The strongest subject material was bis-acryl Protemp 3 Garant. The polymethyl methacry late material, Tempron, was the preferred repair material. A 4-mm connector thickness was the best level. A 45o bevel joint was superior to the butt or fiber joint. The predicted fracture strength of the optimum parameter combination (Protemp 3 Garant/45o bevel joint/Tempron/4 mm connector thickness) was 173.34 N. From the fractographic analysis, different bonding abilities between the same and different resin materials were investigated. Fiber joint groups were nearly all in the cohesive mode without complete catastrophic fracture. Conclusion Within the limitations of this study, these four design factors had different contributions to the fracture strength of repaired provisional restorations. Clinicians must be aware of the sequence of importance in determining better problem-solving methods.

The effect of dentin desensitizer with different layers on thermal changes on the pulp during fabrication of provisional restoration

This study investigated the effects of different desensitizers and an adhesive material application on pulpal temperature rise during direct provisional restoration polymerization. Two dentin desensitizers (Systemp, Ivoclar; BisBlock, Bisco) and a dentin adhesive (Prime Bond, Dentsply) were applied to the dentin surfaces as single layer or double layer. One autopolymerizing methacrylate (Prevision, Heraeus Kulzer) and one light polymerizing composite (Revotek LC, GC) provisional restoration materials were used in this study. A total of 160 dentin disks were prepared from extracted molars. These dentin disks were placed on an apparatus developed to measure temperature rise. After the desensitizer or dentin adhesive application, provisional materials were polymerized according to the manufacturers' instructions. The temperature increase was measured under the dentin disk with a J-type thermocouple wire that was connected to a data logger. Differences between initial and highest temperature reading were taken, and 10 readings were averaged to determine the mean value in temperature rise. Statistical analysis was performed with three-way analysis of variance followed by Tukey HSD test (alpha = 0.05). Temperature rise varied according to the provisional restoration material used (composite resin, methacrylate) (p < 0.001), the agent thickness (single, double) (p < 0.001), and the agent (desensitizer, adhesive) (p < 0.001). The composite resin-based provisional material induced higher thermal changes than methacrylate based provisional material (p < 0.01). The thickness of desensitizing agents affected the thermal changes; however, the desensitizers did not affect on the intrapulpal temperature although the type of provisional material used may be effective.

Effects of Current Provisional Restoration Materials on the Viability of Fibroblasts

The aim of the present study was to evaluate the cytotoxic effects of three different provisional restoration materials on fibroblasts. Two bis-acrylic based [Tempofit Duomix (Detax), Protemp 3 Garant (3M ESPE)] and one urethan dimethacrylate [Revotek LC (GC Corporation)] based provisional restoration materials used. Materials were prepared according to the manufacturers' instructions in standard teflon disks (2x5 mm) and four samples were extracted in 7 ml of Basal Medium Eagle with 10% new born calf serum and 100 mg/ml penicillin/streptomycin for 24 hours. The L929 fibroblast cells were plated (25.000 cells/ml) in well plates, and maintained in a CO(2) incubator at 37 degrees C for 24h. After 24 hours, the incubation medium was replaced by the immersed medium in which the samples were stored and the L929 fibroblasts were incubated in contact with eluates for 24 hours at 37 degrees C for 24h. The fibroblast cell viability was analyzed by measuring the mitochondrial activity with the methyltetrazolium test (MTT). Twelve well used for each specimen and experiment repeated for two times. The data was statistically analyzed by Mann-Whitney U tests. The results showed that, Revotek LC and Protemp 3 Garant were not cytotoxic for fibroblast cells when compared to control group (P>.05). However, Tempofit duomix was cytotoxic for L929 fibroblasts when compared to control group and other tested materials (P<.05). Taking into consideration the limitations of an in vitro study, our study indicate that provisional restoration materials might have cytotoxic effects on fibroblasts and should be selected carefully for clinical applications.

Shear Bond Strength of Provisional Restoration Materials Repaired with Light-cured Resins

This study evaluated the repair bond strengths of light-cured resins to provisional restoration materials with different chemical compositions and polymerization techniques. Fifty discs (10 mm in diameter and 1.5 mm thick) were fabricated for each provisional resin base material, including a self-cured methacrylate (Alike), self-cured bis-acrylate (Protemp 3 Garant), light-cured bis-acrylate (Revotek LC) and a heat-cured methacrylate (Namilon). All specimens were stored in distilled water at 37 degrees C for seven days before undergoing repair with one of four light-cured resins, including AddOn, Revotek LC, Dyractflow and Unifast LC and a self-cured resin (Alike), according to the manufacturers' instructions, for a total of 200 specimens. After 24 hours of storage in 37 degrees C water, the shear bond strengths were measured with a universal testing machine and fracture surfaces were examined under a stereomicroscope. Two-way ANOVA revealed that provisional resin-base material (p < 0.001), repair material (p < 0.001) and their interactions (p < 0.001) significantly affected the repair strength. Tukey's multiple comparisons showed that the lowest bonding strengths were found in specimens of heat-cured methacrylate resin materials repaired with bis-acryl resins, with their failure modes primarily being of the adhesive type. The highest bond strengths were recorded when the provisional resin-base materials and repairing resins had similar chemical components and the failure modes tended to be of the cohesive type.

Temperature rise during polymerization of three different provisional materials

The purpose of this study was to evaluate the temperature rise during polymerization of three different provisional materials by direct method on two different dentin disc thicknesses. Two autopolymerizing; bis-acrylic composite (Fill-in; Kerr), polymethyl methacrylate (Temdent; Weil Dental), and one light polymerizing composite (Revotek LC; GC) provisional restoration materials were used in this study. Sixty dentin discs were prepared from extracted molars (diameter, 5 mm; height, 1 or 2 mm). These dentin discs (1 or 2 mm) were placed on apparatus developed to measure temperature rise. The temperature rise during polymerization was measured under the dentin disc with a J-type thermocouple wire that was connected to a data logger. Statistical analysis was performed with two-way analysis of variance followed by Tukey HSD test (alpha=0.05). Temperature rise values statistically varied according to the provisional restoration material used (light polymerized, auto polymerized; P<0.001) and the dentin thickness (1 and 2 mm; P<0.001). The polymethyl methacrylate based provisional material induced significantly higher temperature rise than other provisional restoration materials at 2-mm dentin thickness (P<0.01). At 1-mm dentin thickness, polymethyl methacrylate and composite induced significantly higher temperature increase than bis-acrylic composite provisional material (P<0.05). The risk for heat-induced pulpal damage should be taken into consideration during polymerization of provisional materials in deep cavities in which dentin thickness is less than 1 mm.

Marginal Adaptation and Color Stability of Four Provisional Materials

A number of provisional restorative materials exist on the market. This study tested marginal fit and color stability of three provisional restorative materials and a control. Two auto-cure materials, Protemp Garant and Integrity, and one dual-cure material, Luxatemp Solar, were tested against SNAP, a polyethyl methacrylate control. A maxillary right central incisor ivorine tooth was prepared for a full coverage all-ceramic crown, with a 1.5-mm chamfer margin. Four points were engraved at a point 1 mm below the facial, lingual, mesial, and distal margins, and replicas (n = 40) were produced by the manufacturer. Provisional crowns (n = 10 x 4) were fabricated on the individual replicas using a polyethylene coping template. The crowns were trimmed under magnification using an acrylic bur. The distance from the crown margins to a point tangent to the engraved markings was measured under 10x magnification and recorded. For color stability, 10-mm diameter x 2-mm thick discs (n = 10 x 4) were fabricated and immersed cyclically in tea for 1 week in a Tucillo/Nielson apparatus. Color measurements were recorded for each specimen at baseline and after staining. DeltaE values were calculated to determine the extent of the color change. The means of the four marginal discrepancy measurements for each specimen were analyzed using a 1-way ANOVA and Tukey post-hoc comparison. Luxatemp Solar had statistically significant marginal discrepancy (319 microm, p < 0.05) when compared to the other provisional materials. A significant color change (DeltaE = 4.33, p < 0.05) was found for Protemp Garant. The dual-cure temporary material (Luxatemp Solar) exhibited significantly more discrepancy at the margin than the auto-cure bis-acryl materials or acrylic control. Protemp Garant exhibited a clinically noticeable change in shade after 1 week in staining solution, whereas the other materials did not exhibit a clinically noticeable change. Provisional crowns fabricated from SNAP, Protemp Garant, and Integrity exhibited similarly low marginal discrepancy. SNAP, Luxatemp Solar, and Integrity did not demonstrate a clinically detectable change in shade after 1 week in a staining solution.

Evaluation and Comparison of the Surface Roughness and Porosity of Different Provisional Restorative Materials: An in vitro Study

ABSTRACT Aim The purpose of this study was to evaluate and compare the surface roughness and porosity of different provisional restorative materials. Materials and methods Provisional restorative materials were divided into following three groups: Dental products of india (DPI), Protemp, Tempofit. For each group, wax block with 20 × 10 × 3 mm was made for making vinyl polysiloxane impression material to give 12 samples in each group of three different provisional restorative materials. The acrylic resin was inserted into the silicon impression mold. A total of 12 specimens of one material were obtained. The specimens were finished with the help of lathe using a sequence of grit sand paper. The surface roughness was verified with the help of a micron dial indicator. To facilitate the porosity readings, the specimens were immersed in dye for 2 hours. The number of pores in each area was determined with a stereomicroscope with magnification 1× 50× to check the porosity of three different provisional restorative materials. Values were subjected to statistical analysis. Results Analysis of variance (ANOVA) test was used to compare between Tempofit, Protemp, and DPI. The results obtained indicated that surface roughness of Protemp was least compared with Tempofit and DPI. The ANOVA test was used to check surface area of porosities in each provisional material, followed by Kruskal–Wallis test and Mann–Whitney test (highly significant) (p &lt; 0.001). The results obtained indicate that Protemp material showed the least number of porosities and minimal surface roughness followed by Tempofit and DPI. Henceforth, it can be concluded that among the three tested materials, Protemp was the best material which can be used for provisional restorations. Conclusion Surface roughness and porosity were compared among Protemp, Tempofit, and DPI material; the best results were obtained with the use of Protemp material which had shown the least number of porosities and minimal surface roughness. How to cite this article Kumar GV, Devi R, Anto N. Evaluation and Comparison of the Surface Roughness and Porosity of Different Provisional Restorative Materials: An in vitro Study. CODS J Dent 2016;8(1):39-45.