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Esthetically pleasing temporary prostheses are often necessary for extended periods in a variety of clinical scenarios. Adjustments to the occlusion or margins are commonly needed before cementing the temporary prosthesis. Therefore, it is clinically necessary to repolish the rough surface to avoid biological and esthetic issues associated with rough surfaces. The purpose of this in vitro study was to assess and compare the impact of various polishing protocols on the surface roughness and color stability of three resin materials used for provisional crowns. A total of 150 specimens were fabricated from auto-polymerizing polymethyl methacrylate, bis-acryl composite, and Methyl methacrylate-LC resin using a stainless steel mold. Each material group was divided into five groups (n = 10) based on the applied surface treatment: positive control group (G1): no roughening or surface treatment, Negative control group (G2): acrylic bur-roughened surface without any polishing, the different surface treatment groups of silicon carbide and aluminum oxide stone polishing (G3), diamond-coated rubber twist (G4), and Surface Glaze (G5). An optical profilometer was used to assess the surface roughness of all samples. After undergoing 6000 cycles of thermocycling followed by immersion in a coffee solution for 15 days at 37 °C, color parameters were measured using a spectrophotometer both before and after a storage period to evaluate color differences. A two-way ANOVA test with α = 0.05 significance level was carried out to determine the impacts of both the materials utilized and the polishing protocol. Among the three types of resin examined, the bisacryl group exhibited superior surface quality in positive control groups, while PMMA resin demonstrated higher polishability. The diamond-coated rubber twits resulted in lower Ra values of 0.36 (0.01) µm, 0.52 (0.11) µm, and 0.28 (0.05) µm for PMMA, BAMA, and MMLC resins, respectively. The application of photo-polymerized surface glaze led to a plaque accumulation threshold of 0.2 µm across all resin groups. The greatest mean color change occurred in the negative control group, indicating a propensity for more staining on rougher surfaces. The Bisacryl resin exhibited higher ΔE values, whereas PMMA showed better color stability. The lowest ΔE values were found when the surface glaze was applied to all of the provisional crown resins. Untreated Bisacryl resin exhibited the lowest Ra values, while PMMA resins demonstrated superior surface morphology after polishing. PMMA provisional crown resins showed increased resistance to staining. The use of surface glaze enhanced both smoothness and color stability on the surfaces. [ABSTRACT FROM AUTHOR]

BACKGROUND: The issue of an increase in pulpal temperature affects direct and indirect techniques, where the fabricating material will come in direct contact with the prepared teeth. OBJECTIVE: The aim of this study was to assess the pulpal thermal variations during provisional fabrication using direct and indirect-direct techniques, with three commonly commercially available provisional fabricating materials. METHOD: In this vitro analytical study, 120 extracted human teeth were placed in a dentulous mould and dental stone was poured, to create a working model with an embedded natural right maxillary central incisor. Recording of thermal changes in the pulp chamber during provisionalization with direct (technique 1) and indirect-direct (technique 2) using three common types of provisional crown materials. 120 provisional crowns were fabricated using polymethyl methacrylate (DPI) (Group 1), Bis-acryl composite (Protemp 4) (Group 2) and Visible-light polymerizing (VLP) Urethane Dimethacrylate (Revotek LC) (Group 3) by two techniques and recording of peak temperature changes were done. Temperature rise in the pulp chamber was recorded using a thermocouple. RESULTS: The mean initial and final temperature of the pulp chamber recorded for Groups 1, 2 and 3 was 31.52, 32.56; 31.01, 32.34; 32.29, 34.47 for technique 1 and 29.13, 30.5; 29.29, 31.11; 30.31, 32.65 for technique 2. The mean change in temperature was higher in Group 3 compared to the other groups. CONCLUSION: The temperature rise detected according to this study was within the safer pulpal health limits with all the investigated materials and techniques. The resin material recommended for clinical use when the direct technique is employed for the fabrication of provisional crowns is bis-acryl composite resin (Protemp-4) as it caused minimal temperature rise in the pulpal chamber. [ABSTRACT FROM AUTHOR]

Esthetically pleasing temporary prostheses are often necessary for extended periods in a variety of clinical scenarios. Adjustments to the occlusion or margins are commonly needed before cementing the temporary prosthesis. Therefore, it is clinically necessary to repolish the rough surface to avoid biological and esthetic issues associated with rough surfaces. The purpose of this in vitro study was to assess and compare the impact of various polishing protocols on the surface roughness and color stability of three resin materials used for provisional crowns. A total of 150 specimens were fabricated from auto-polymerizing polymethyl methacrylate, bis-acryl composite, and Methyl methacrylate-LC resin using a stainless steel mold. Each material group was divided into five groups (n = 10) based on the applied surface treatment: positive control group (G1): no roughening or surface treatment, Negative control group (G2): acrylic bur-roughened surface without any polishing, the different surface treatment groups of silicon carbide and aluminum oxide stone polishing (G3), diamond-coated rubber twist (G4), and Surface Glaze (G5). An optical profilometer was used to assess the surface roughness of all samples. After undergoing 6000 cycles of thermocycling followed by immersion in a coffee solution for 15 days at 37 °C, color parameters were measured using a spectrophotometer both before and after a storage period to evaluate color differences. A two-way ANOVA test with α = 0.05 significance level was carried out to determine the impacts of both the materials utilized and the polishing protocol. Among the three types of resin examined, the bisacryl group exhibited superior surface quality in positive control groups, while PMMA resin demonstrated higher polishability. The diamond-coated rubber twits resulted in lower Ra values of 0.36 (0.01) µm, 0.52 (0.11) µm, and 0.28 (0.05) µm for PMMA, BAMA, and MMLC resins, respectively. The application of photo-polymerized surface glaze led to a plaque accumulation threshold of 0.2 µm across all resin groups. The greatest mean color change occurred in the negative control group, indicating a propensity for more staining on rougher surfaces. The Bisacryl resin exhibited higher ΔE values, whereas PMMA showed better color stability. The lowest ΔE values were found when the surface glaze was applied to all of the provisional crown resins. Untreated Bisacryl resin exhibited the lowest Ra values, while PMMA resins demonstrated superior surface morphology after polishing. PMMA provisional crown resins showed increased resistance to staining. The use of surface glaze enhanced both smoothness and color stability on the surfaces.

(1) Purpose: The aim of the present study was to compare the bond strength between two 3D-printed resins designed for long-term provisional crowns and three different reline materials. (2) Materials and Methods: Rectangular specimens were prepared from two 3D-printed resins (Envision Tech and NextDent C&B) and a conventional self-cure PMMA. Transparent tubes filled with three different reline materials including composite resin, Bis-acryl, and PMMA were bonded to the 3D-printed specimens (n = 11 per group, total of 6 study groups). Tubes filled with PMMA were bonded to the prepared PMMA specimens which served as the control group (n = 11, control group). The specimens were subjected to a shear bond strength (SBS) test, and mode of failure was recorded using light microscopy. Statistical analysis was performed using a one-way ANOVA and post hoc Tukey's tests (alpha = 0.05). (3) Results: The highest SBS value was achieved to both 3D-printed materials with the PMMA reline material. The bond to both 3D-printed materials was lower with Bis-acrylic or composite resin relines in comparison to that with PMMA (p-value < 0.05). No significant difference was found between the control PMMA group and either 3D-printed material when relined with PMMA (p-value > 0.05). (4) Conclusion: The tested 3D-printed resins achieved a clinically acceptable bond strength when relined with PMMA. [ABSTRACT FROM AUTHOR]

Introduction: Dental caries remains a constant problem in clinical practice. The rates of recurrent caries around long-term provisional restorations may be even higher due to poor marginal adaptation and less stable materials. Since provisional crowns luted with provisional cement are susceptible to bacterial infiltration and caries, antibacterial and anticariogenic agents have been added to provisional cement, and retention of the provisional crown has been evaluated in this study. Materials and Methods: Ten extracted maxillary first premolar teeth were selected. Standardised tooth preparation was done. A total of 40 provisional crowns were fabricated using tooth-coloured auto-polymerising acrylic resin. The prepared provisional crowns were divided into four groups of 10 crowns each. Crowns were cemented on the prepared teeth after enriching with the three solutions individually. All specimens were stored in 100% humidity at 37°C for 1 h, thermocycler 100 times between 5°C and 55°C with a dwell time of 10 s and then stored at 100% humidity at 37°C. Cemented crowns were subjected to tensile dislodgement force using a universal testing machine with a crosshead speed of 5 mm/min. Results: Provisional cement enriched with Profluorid Varnish has shown properties of the highest tensile dislodgement force, with chlorhexidine-reduced retention. Conclusion: The present study concluded that Profluorid Varnish, as an additive in non-eugenol provisional cement (Provicol), is more effective in increasing retention.

Prosthetic treatment, in general, has a significant impact on quality of life, with clinically relevant indicators and statistically verified effects over time. Material and methods: our research involved 172 patients who were treated with dental bridges, partial removable dentures, or complete removable dentures. Replacement of partially detachable and complete removable dentures that no longer matched the stomatognathic system’s functionality, as well as the installation of new dental bridges, were among the treatments. Results: the results of the present study showed that the majority of patients initially assessed their dental health as moderate (36.3 percent) or good (48.6%), whereas their overall health was rated as superior (56.4%).

Introduction: As the adhesion of microorganisms to the surfaces of the dentures is a prerequisite for microbial colonization, the development of methods that can reduce the adhesion of C. albicans may represent a significant advance in the prevention of dentures-induced stomatitis. Although due to the increase in awareness about oral health care, the number of edentulous patients has decreased, but there are still a large number of denture wearers in countries such as Romania.

Objective: To evaluate the performance of the indirect technique in peri‐implant soft tissue contour duplication after the delivery procedure in the anterior maxilla. Materials and Methods: Patients with single implant‐supported fixed restorations in the anterior maxilla were recruited. For the impression procedure, an intraoral scan was acquired by both the direct and the indirect techniques. For the delivery procedure, implants were randomly allocated into one of the two groups according to the approaches of digital impression preceding definite crown fabrication (A—direct technique; B—indirect technique) and were scanned again after the definite crown delivery. The stereolithography files were superimposed to analyze changes in peri‐implant soft tissue contour after the delivery procedure. The main outcomes were dimensional deviations of peri‐implant mucosa, and the secondary outcome was differences in the pink esthetic score (PES). Results: A total of 20 implants that underwent the complete workflow were included. After the delivery procedure, significant deviations in palatal tissue thickness between the provisional and definite crowns were observed in Group A but these were absent in Group B. Additionally, deviations in labial thickness (0.27 ± 0.12 mm vs. 0.08 ± 0.09 mm) and palatal thickness (0.17 ± 0.15 mm vs. 0.03 ± 0.08 mm), and labial volume of soft tissue (1.87 ± 0.94 mm3 vs. 0.75 ± 0.74 mm3) in Group A were significantly higher than those in Group B. No significant differences in PES were found. Conclusion: The indirect technique of scanning the provisional crown can more accurately duplicate the peri‐implant soft tissue contour than the direct technique, resulting in a smaller deviation of the soft tissue in the delivery procedure. [ABSTRACT FROM AUTHOR]

Objectives Provisional crowns play an integral role in prosthodontic therapy and need to be fabricated with high accuracy to ensure good marginal fit and proper contour. The aim of this study is to evaluate the effect of 3D printer's horizontal pixel resolution on trueness of the intaglio surface, external surface, and marginal area and the actual marginal adaptation of the interim crowns. Materials and Methods A gypsum reference model of mandible with a prepared right first molar was scanned with a dental laboratory scanner (AutoScan-DS-MIX, Shining 3D) and a digital provisional crown was design using the computer-aided design (CAD) software (Exocad). The provisional crown was manufactured by two printers with different horizontal resolutions (Sonic Mini 4K Printer and Sonic Mini 8K Printer). The printed crowns were scanned using the aforementioned scanner. The trueness of the external surface, internal surface, and marginal area of the provisional crowns was evaluated by comparing the scanned data with the reference CAD design data using a 3D inspection software (Geomagic Control X, 3D systems). The trueness of the crown manufactured by two printers was compared by a two-sided test (α = 0.05). Finally, the marginal adaptation of the provisional crowns was evaluated on the printed removable dies and compared. Results The results revealed that there was a significant difference in the trueness of the marginal area and the marginal adaptation (p < 0.05). Conclusions It can be concluded that the trueness of provisional crown marginal area and the marginal adaptation was affected by the horizontal resolution of the 3D printer. [ABSTRACT FROM AUTHOR]

Introduction: Provisional restorations must protect the fresh cut enamel, protect the dental pulp, produce occlusal rebalancing and especially restore the lost aesthetic function Data are needed to help predict color stability of provisional resins. The present study was conducted to assess discoloring of PMMA and bis-acrylic based interim crowns in different conditions, after a certain period of time, respectively 7 days and 60 day of submersing the samples both in artificial saliva and in solutions that will cause a change of color. The solutions that we chose were made of artificial saliva and coffee and artificial saliva and green tea, which are the most common beverage among patients.

Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30–50% carbon fibers can be a suitable material for the various implant components in dentistry. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impacts of finish line type and width on the fracture resistance of provisional crowns, and to determine the suitable type of crown material to use for that purpose. Chamfer and rounded shoulder preparations were done with stainless steel master models with a width of 0.6 mm and 1.0 mm and a total convergence angle of 6°. The provisional crowns were obtained using computer-aided design/computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA) material in the mandibular left first molar. From the obtained molar tooth, a silicon mold was used to obtain the provisional crowns from the CAD/CAM PMMA, bis-acrylic resin, and self-curing composite materials. The lowest fracture strength was found in the bis-acrylic resin group made using the rounded shoulder preparation with a width of 0.6 mm (699 N). The highest fracture strength was found in the CAD/CAM PMMA group made using the rounded shoulder preparation with a width of 1 mm (1339 N). The fracture strength is higher for CAD/CAM PMMA than the other provisional crown materials; thus, it is recommended that this material be used in provisional crown restorations due to its other advantages. [ABSTRACT FROM AUTHOR]

Introduction: Functional and aesthetic outcome is an indication of successfully dental implant treatment. Single implant with chairside immediate provisional crown loading is preferred treatment for patient aesthetic demand and implant survival success. Objective: This case report is to show an alternative procedure to get good functional, aesthetic, less morbidity, and reducing treatment period with a chairside immediate provisional crown. Case: A 54 years old women wanted to replace her missing upper left canine with a dental implant. She hoped that this procedure would not affect her appearance. A single implant with 4 mm diameter and 10 mm height was placed in the upper left canine area. A rigid abutment was installed, and a chairside provisional crown was built at a rigid cap immediately after surgery. Conclusion: A chairside immediate provisional crown after a single implantation procedure is a very good alternative to get an aesthetic, functional, morbidity, and shorter treatment.

Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30–50% carbon fibers can be a suitable material for the various implant components in dentistry.

Background: With the advent of new provisional crown materials, it has become imperative to evaluate their marginal fit and strength to select the ideal provisional crown material. Aim: The purpose of this in vitro study was to evaluate and compare the vertical marginal fit and flexural strength of provisional crowns prepared using computer-aided design-computer-aided manufacturing (CAD-CAM) temporary material versus those fabricated using bis-acrylic composite-based autopolymerizing resin material. Materials and Methods: Eighty samples were divided into two equal Groups (I and II). Group I consisted of forty samples that were evaluated for flexural strength and Group II consisted of forty samples that were evaluated for their vertical marginal fit. Group I was subdivided as Group IA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks and Group IB, i.e., CAD/CAM provisional material blocks. Similarly, Group II was subdivided as Group IIA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns and Group IIB, i.e., CAD/CAM provisional material crowns. Marginal adaptation was evaluated using stereomicroscope and image analyzing software to measure the amount of marginal gap. For flexural strength, all specimens were subjected to a standard compression load in the universal testing machine until fracture occurred. Data were analyzed using Student's t-test (P = 0.001). Results: CAD/CAM provisional crowns showed better marginal adaptation (34.34 μm) as compared to bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns (63.42 μm) (P < 0.001). The flexural strength of CAD/CAM blocks (94.06 megapascals [MPa]) was not statistically different from bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks (101.41 MPa) (P > 0.001). Conclusion: Protemp™ 4 and CAD/CAM provisional materials have comparable flexural strength. However, the marginal fit of temporary crowns fabricated by CAD/CAM was found to be superior to the ones fabricated using bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4).

The purpose of this study was to evaluate the dimensional accuracy of crowns fabricated using a polyvinyl alcohol (PVA) dental model. An intraoral scanner (LAVA TDS) was used to scan a prepared molar abutment as a master model. The STL file obtained from the scanning process was transferred into the FDM 3D printer (Value 3D Magix MF-1000) and then models were fabricated with PVA filament. In order to compare with the conventional method, an impression of the master model was taken using silicone impression material to fabricate the conventional stone cast model (Conv). An indirect resin composite (Gradia) and self-cured acrylic resin (Curergrace) were used to fabricate crowns (n = 20) according to the manufacturer's instructions. Surface accuracy of the Conv and PVA models and internal accuracy of the crowns set on the models were measured using two methods; 3D digital analysis and silicon-fitting evaluation. Statistical analysis of the results was done using t -test and Willcoxon signed rank test with Bonferroni correction at 5% significance. Digital analysis showed the Root Mean Square (RMS) value of PVA model surface was higher than that of Conv, while there was no significant difference between the two crown materials. However, the silicon-fitting analysis showed marginal discrepancy of crowns fabricated on PVA model were within 100 µm. 3D printed PVA model can be used for chairside crown fabrication with an acceptable accuracy. [ABSTRACT FROM AUTHOR]

Purpose: A key challenge in implant treatment in the esthetic zone is to provide patients with crowns and peri-implant mucosa that are in harmony with the adjacent teeth to restore both function and esthetics. The aim of the present study was to show the preliminary results of an immediate loading protocol in the maxillary esthetic zone that is designed to preserve the soft tissue. Materials and Methods: Patients were treated with immediately loaded single-tooth implants (Seven, MIS). Implants were inserted in fresh postextraction sites or in single edentulous sites with clinically and radiologically healed bone. After 8 weeks of loading, the provisional crowns and abutments were modified as needed to enhance the esthetics of the gingival margins. Definitive restorations were delivered 4 to 6 months postoperatively. Results: Seventy patients were treated; 25 implants were placed in fresh extraction sites, and the remaining 45 implants were inserted in healed single edentulous sites. All implants were stable, and radiographs showed complete osseointegration after 1 year of functional loading. Conclusions: The present study shows promising results for immediate loading of single implants. All implant sites fulfilled success criteria in terms of function and esthetics, and particularly promising results were seen following additional adjustments of the provisional restorations to preserve interdental papillae. [ABSTRACT FROM AUTHOR]

Objective: In part 1 of this study, the authors showed that coating polymethyl methacrylate (PMMA) provisional restorations with bonding resin (BR) or liquid polish (LP) significantly reduced early in vivo biofilm formation on these restorations. The aim of the present study was to determine the mechanism through which these materials inhibit biofilm formation. Method and Materials: The antimicrobial properties of the tested materials were examined using the agar diffusion test (ADT) and the direct contact test (DCT). Surface energy was determined using contact angle measurements; salivary protein adsorption was analyzed by polyacrylamide gel electrophoresis (SDS-PAGE). Results: ADT and DCT showed that the tested materials had no antimicrobial properties. Contact angle measurements revealed that liquid polish and PMMA have a similar contact angle, tending toward the hydrophobic region, and that bonding resin was more hydrophilic. SDS-PAGE analysis showed a significant reduction in salivary protein adsorption to the tested materials compared with that to the PMMA control. Conclusion: Liquid polish prevents biofilm formation by preventing protein adsorption. [ABSTRACT FROM AUTHOR]

Objective: Biofilm accumulation on provisional restorations may affect the surrounding tissues' integrity. The purpose of this study was to test in vivo biofilm formation on polymethyl methacrylate (PMMA) self-cured acrylic resin provisional crowns. Method and Materials: Three types of PMMA surfaces were tested: (1) polished, (2) polished and coated with bonding agent, and (3) polished and coated with light-cured liquid polish. After 12 hours in the oral cavity, the crown was removed and examined by confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM). Results: Biofilm, 250 μm thick, was observed with CLSM on the polished acrylic surface. Significantly less bacterial accumulation was observed on the crowns coated with bonding agent, whereas no biofilm was observed on the crowns coated with liquid polish (P < .001). SEM examination confirmed these findings. Conclusions: Bonding resin or liquid polish coatings significantly reduce early biofilm formation, which in turn might affect the overall plaque accumulation on provisional restorations. [ABSTRACT FROM AUTHOR]

Interim restoration protects abutment teeth and periodontal tissues until prosthetic treatment ends with the fabrication of a definitive prosthesis, restores and maintains the functions and morphology of the stomatognathic system, and preserves the occlusal contact relationship. Temporary prostheses are used for a short time, to confirm the diagnosis and treatment plan. However, because interim restorations are used only briefly, their importance in ensuring the success of definitive prostheses is often overlooked. This review includes a comprehensive literature review of interim restoration of molars and summarizes the current clinical understanding and status of this functionally important area. Peer-reviewed publications were identified by searching PubMed in November 2018. An interim restoration, even when used briefly, can help dentists evaluate many aspects of the treatment plan and contribute to accurate prognosis of prosthetic treatment. [ABSTRACT FROM AUTHOR]

Background: With the advent of new provisional crown materials, it has become imperative to evaluate their marginal fit and strength to select the ideal provisional crown material. Aim: The purpose of this in vitro study was to evaluate and compare the vertical marginal fit and flexural strength of provisional crowns prepared using computer-aided design-computer-aided manufacturing (CAD-CAM) temporary material versus those fabricated using bis-acrylic composite-based autopolymerizing resin material. Materials and Methods: Eighty samples were divided into two equal Groups (I and II). Group I consisted of forty samples that were evaluated for flexural strength and Group II consisted of forty samples that were evaluated for their vertical marginal fit. Group I was subdivided as Group IA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks and Group IB, i.e., CAD/CAM provisional material blocks. Similarly, Group II was subdivided as Group IIA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns and Group IIB, i.e., CAD/CAM provisional material crowns. Marginal adaptation was evaluated using stereomicroscope and image analyzing software to measure the amount of marginal gap. For flexural strength, all specimens were subjected to a standard compression load in the universal testing machine until fracture occurred. Data were analyzed using Student's t-test (P = 0.001). Results: CAD/CAM provisional crowns showed better marginal adaptation (34.34 μm) as compared to bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns (63.42 μm) (P < 0.001). The flexural strength of CAD/CAM blocks (94.06 megapascals [MPa]) was not statistically different from bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks (101.41 MPa) (P > 0.001). Conclusion: Protemp™ 4 and CAD/CAM provisional materials have comparable flexural strength. However, the marginal fit of temporary crowns fabricated by CAD/CAM was found to be superior to the ones fabricated using bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4). [ABSTRACT FROM AUTHOR]

PURPOSE. To compare and analyze trueness and precision of provisional crowns made using stereolithography apparatus and subtractive technology. MATERIALS AND METHODS. Digital impressions were made using a master model and an intraoral scanner and the crowns were designed with CAD software; in total, 22 crowns were produced. After superimposing CAD design data and scan data using a 3D program, quantitative and qualitative data were obtained for analysis of trueness and precision. Statistical analysis was performed using normality test combined with Levene test for equal variance analysis and independent sample t-test. Type 1 error was set at 0.05. RESULTS. Trueness for the outer and inner surfaces of the SLA crown (SLAC) were 49.6±9.3 µm and 22.5±5.1 µm, respectively, and those of the subtractive crown (SUBC) were 31.8±7.5 µm and 14.6±1.2 µm, respectively. Precision values for the outer and inner surfaces of the SLAC were 18.7±6.2 µm and 26.9±8.5 µm, and those of the SUBC were 25.4±3.1 µm and 13.8±0.6 µm, respectively. Trueness values for the outer and inner surfaces of the SLAC and SUBC showed statistically significant differences (P<.001). Precision for the inner surface showed significance (P<.03), whereas that for the outer surface showed no significance (P<.58). CONCLUSION. The study demonstrates that provisional crowns produced by subtractive technology are superior to crowns fabricated by stereolithography in terms of accuracy. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was 'to appraise the fracture strength of provisional crown and fixed partial denture resins with an in vitro test system. Materials and Methods: Bar-type specimens were fabricated according to American National Standards Institute/American Dental Association specification number 27. Reinforcement materials; polyethylene fiber and glass fiber are compared. Provisional crown-bridge materials are autopolymerising Poly Ethyl Metacrylate (PEMA), autopolymerising Poly Methyl Metacrylate (PMMA), bis-acryl composite resin and light cured composite resin). A total of 150 specimens are arranged for the flexural strength test. The specimens are divided into 5 groups according to the type of resin used (Dentalon Plus, Tetric Ceram, Charisma, Protemp 3, TAB 2000) and then every group was distributed into 3 subgroups rendering to the type of fiber reinforcement (Construct, Fiber-splint ML). Unreinforcement specimens functioned as the control. Specimens were fractured in a universal testing instrument until the point of rupture. Mean flexural strengths were calculated in MPa. Comparisons were completed with analysis of variance and then Duncan's multiple range tests. Results: Mean flexural strengths ranged from 63.45 to 397.8 MPa. There are statistical difference between the groups (Fiber-splint ML, Construct and control). Conclusion: Flexural strengths were material- rather than classification precise. Several, but not all, bis-acryl resins validated expressively superior flexural strength over traditional methacrylate resins. There was significant difference between Fiber-splint ML, Construct and control group. [ABSTRACT FROM AUTHOR]

Aim: The present study was to evaluate the space provided for the temporary luting cement, after the application of various coats of die spacers, during the fabrication of provisional crowns and bridges. Materials and Methods: A total of 50 specimens of dental stone with provisional crowns on all these samples were prepared and were divided into five groups based on the application of various coats of different die spacers. Later these specimens were sectioned buccolingually and were observed using a stereomicroscope under 100X magnification. The images thus obtained were evaluated and noted for the amount of space between the inner surface of the provisional crown and the specimens at five different locations using Image Pro 6.0 Express software and the values were subjected to one-way ANOVA test, and unpaired t-test. Results: There was a significant increase of luting space thickness with various die spacer applications than the specimens of control group. Conclusion: Specimens of double coat applications of silver and gold die spacers showed higher luting cement space than the separating media application specimens.

This study concerned the effect of heat treatment during setting on the physical properties of four resin-based provisional restorative materials: Duralay (polymethyl methacrylate), Trim II (polyethyl methacrylate), Luxatemp (bis-acrylic composite), and Protemp 4 (bis-acrylic composite). Specimens were prepared at 23, 37, or 60 °C for evaluation of flexural strength, surface roughness, color change and marginal discrepancy. Flexural strength was determined by a three-point bending test. Surface profile was studied using atomic force microscopy. Color change was evaluated by comparing the color of the materials before and after placement in coffee. A travelling microscope helped prepare standardized crowns for assessment of marginal discrepancy. Flexural strength of all tested materials cured at 23 °C or 37 °C did not significantly change. The surface roughness and marginal discrepancy of the materials increased at 60 °C curing temperature. Marginal discrepancies, color stability, and other physical properties of materials cured at 23 °C or 37 °C did not significantly change. Flexural strength of certain provisional materials cured at 60 °C increased, but there was also an increase in surface roughness and marginal discrepancy. [ABSTRACT FROM AUTHOR]

The displacement of a dental implant into the maxillary sinus may lead to implant failure due to exposure of the apical third or the tip of the implant beyond the bone, resulting in soft tissue growth. This case report discusses dental implant placement in the upper first molar area with maxillary sinus involvement of approximately 2 mm. A new technique for progressive implant loading was used, involving immediately loaded implants with maxillary sinus perforation and low primary stability. Follow-up was performed with resonance frequency analysis and compared with an implant placed adjacent in the upper second premolar area using a conventional delayed loading protocol. Implants with maxillary sinus involvement showed increasing stability during the healing period. We found that progressive implant loading may be a safe technique for the placement of immediately loaded implants with maxillary sinus involvement. [ABSTRACT FROM AUTHOR]

Aim: The present study was to evaluate the space provided for the temporary luting cement, after the application of various coats of die spacers, during the fabrication of provisional crowns and bridges. Materials and Methods: A total of 50 specimens of dental stone with provisional crowns on all these samples were prepared and were divided into five groups based on the application of various coats of different die spacers. Later these specimens were sectioned buccolingually and were observed using a stereomicroscope under 100X magnification. The images thus obtained were evaluated and noted for the amount of space between the inner surface of the provisional crown and the specimens at five different locations using Image Pro 6.0 Express software and the values were subjected to one-way ANOVA test, and unpaired t-test. Results: There was a significant increase of luting space thickness with various die spacer applications than the specimens of control group. Conclusion: Specimens of double coat applications of silver and gold die spacers showed higher luting cement space than the separating media application specimens. [ABSTRACT FROM AUTHOR]

Abstract Provisional Crown Fabrication Maxillary Left Central Incisor is a video that teaches dental students how to manufacture a provisional crown on a maxillary central incisor in patient simulation using composite resin crown material. The videos have been used for the last 2 years and were well valued by both students and faculty.

Treatment of trauma to anterior teeth should aim at preserving the affected teeth so as to restore function and esthetic appearance. Recently, patients have come to expect adequate esthetics immediately after trauma. In the present case, a deep crown-root fracture compromised the pulp and extended subgingivally on the palatal aspect. After using the fractured fragment as a provisional crown, the patient received conventional root canal treatment, which provided immediately satisfactory esthetic results and reliable short-term restoration of the crown-root fractured tooth. Rehabilitation of the fractured central incisor was performed with a post-core-supported prosthetic restoration. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: This study aimed to investigate the flexural strength (FS) and flexural modulus (FM) of provisional crown and bridge materials at different storage times after mixing using materials with different curing mechanisms (dual-curing vs. self-curing). Methods: FS and FM of four proprietary materials (Trim, Luxatemp AM Plus, Luxatemp AM Plus Solar and Cool Temp Natural) were tested in a 3-point bending test according to EN ISO 4049:2000 at various times after mixing (37°C dry/water) including thermocycling (5000×, 5–55°C). Mean values of all measurements were calculated and subjected to the Games–Howell test (p =0.05) as well as a regression analysis (p =0.05). A two-way ANOVA (p =0.05) was used to identify the influence of the curing mechanism and chemical nature of the materials used. Results: FS ranged between 11.1 and 24.0MPa and FM between 82.5 and 548.2MPa for all tested materials except for the dual-curing material (FS: 82.4MPa; FM: 2060MPa) 10min after mixing. The r 2-values, describing the goodness-of-fit of the regression curve for the relation between the mechanical properties and storage time, ranged from 0.701 to 0.979 for the composite based materials and 0.671 to 0.685 for the methacrylate resin. The chemical nature and curing mechanism significantly influenced (p <0.001) the mechanical properties, however, the influence of the curing mechanism disappeared at progressive points in time after mixing comparing Luxatemp AM Plus versus Luxatemp AM Plus Solar. Conclusions: FS and FM significantly depend on the time after mixing. Composite resin based materials are preferred versus methacrylate resins due to more favourable mechanical properties. If a high mechanical strength is indispensable directly after fabrication, a dual-curing provisional material is recommended. [Copyright &y& Elsevier]

This study evaluated the surface roughness of polished provisional materials at baseline and after storage in artificial saliva and artificial saliva–coffee solutions. Ten specimens (25 mm × 25 mm × 2 mm) of 12 commercially available provisional crown materials (5 methacrylate and 7 bis-acryl resins) were fabricated and polished. Baseline surface roughness measurements (Ra) were made using a surface roughness tester. Specimens were divided into 2 groups and stored in artificial saliva or artificial saliva–coffee solution at 37°C for 2 weeks. Baseline surface roughness data were analyzed using the analysis of variance; multiple comparisons adjustment was made using the Tukey method. Multiple linear regression methods were used to analyze change in roughness relative to baseline and to assess the impact of storage medium, material, and baseline roughness on this change, including potential interactions among these 3 factors; descriptors of poststorage surface roughness were obtained. Alike demonstrated the greatest surface roughness, both at baseline and after storage ( p < 0.05 after adjustment for all Pairwise comparison by Tukey method). Temphase, Temporary Bridge Resin, Instatemp, Unifast, Jet, and Zeta had the lowest baseline surface roughness measurements. The lowest poststorage roughness scores were associated with Protemp Garant, Jet, and Integrity. Five materials (Protemp Garant, Instatemp, Unifast, Jet, and Zeta), formed the group having the lowest rough poststorage outcomes. The data provided strong evidence of a material effect ( p < 0.0001) at baseline. Evaluation of change in Ra following storage indicated that surface roughness increased for the majority of materials after storage in a moist environment, and that provisional crown materials that exhibit less initial surface roughness tend to undergo greater surface roughness change in a moist environment. Strong indications were found that the effect of the type of storage solution used differed among the materials. There were significant differences in surface roughness of provisional crown materials when polished under the same conditions. Methacrylate resins in general exhibited smoother surfaces after initial polishing. Surface roughness increased for nearly all materials after storage in either moist environment. [ABSTRACT FROM AUTHOR]

Objective: To observe the changes of peri-implant tissue around the individualized abutment that was grinded from zirconia provisional crown in one year. Methods: In this research, a prosthodontic-driven virtual implant planning and immediate provisionalization were conducted in computer assisted design software. And computer-aided design/computer-aided manufacturing (CAD/CAM) techniques were used to fabricate the zirconia provisional crown and surgical guide template before surgery. The implant was accurately placed with the surgical guide, and the zirconia provisional crown was immediately delivered after surgery. Three months later, the implant osseointegration was completed, and zirconia provisional crown was prepared intraorally to generate customized zirconia abutment for final prosthesis. The study included 30 patients with single anterior tooth loss, including 18 males and 12 females, aged from 26 to 50 years old, and the mean age was (36.2±6.1) years old. The patients were from the Center of Oral Implantology, The First Affiliated Hospital of Zhejiang University Medical College from January 2017 to February 2018. After cementation of the final prosthesis, the cases were followed up at 6 and 12 months time intervals. Implant survival rate, probing depth, bleeding on probing, marginal bone level loss and papilla index score (PIS) were recorded in every appointment. Results: The survival rate of 30 implants was 100%, and the probing depths were less than 5 mm. The bone resorption at 6 and 12 months follow-up after the final delivery was 0 (0, 0) mm and 0 (-0.2, 0) mm, respectively, and the difference was not statistically significant ( P >0.05). The PIS was 3.0 (2.0, 4.0), 3.0 (2.8, 4.0) and 3.0 (3.0, 4.0) on the final delivery, 6 and 12 months after final delivery, respectively. Conclusions: Marginal bone level and bone loss were stable with this new implant clinical protocol at the one-year follow-up.

Interim restoration protects abutment teeth and periodontal tissues until prosthetic treatment ends with the fabrication of a definitive prosthesis, restores and maintains the functions and morphology of the stomatognathic system, and preserves the occlusal contact relationship. Temporary prostheses are used for a short time, to confirm the diagnosis and treatment plan. However, because interim restorations are used only briefly, their importance in ensuring the success of definitive prostheses is often overlooked. This review includes a comprehensive literature review of interim restoration of molars and summarizes the current clinical understanding and status of this functionally important area. Peer-reviewed publications were identified by searching PubMed in November 2018. An interim restoration, even when used briefly, can help dentists evaluate many aspects of the treatment plan and contribute to accurate prognosis of prosthetic treatment.

Objective: Implants placed in the posterior region of the maxilla have a high incidence of implant failure due to poor bone quality, especially when immediate implant loading is needed. Immediate Progressive Loading (IPL) can enhance bone quality and may offer an alternative solution when Immediate Implant loading is needed., Methods: Six patients (one male and five females; 34-62 years old) were included in this study. Twelve implants were inserted in the posterior region of the maxilla. Resonance Frequency Analysis (RFA) was performed at the time of implant placement and after 1, 2, 3 and 6 months. ISQ (Implant Stability Quotient) values were compared between the Delayed Loading (DL) group after 2 months and the Progressive Loading (PL) group and between different time points for each group., Results: At implant placement, the mean ISQ values for PL and DL implants were 63 and 57, respectively. One month after implant placement, the mean ISQ value for PL implants was 73.Two months after implant placement, the mean ISQ value for PL implants was 75. Three months after implant placement, the mean ISQ values for PL and DL implants were 76 and 69, respectively. Six months after implant placement, the mean ISQ values for PL and DL implants were 79 and 76, respectively., Conclusion: Despite its limitations, this pilot study indicated that compared to DL, PL can enhance bone density and implant stability, resulting in greater early functionality and fewer surgery sessions.

Background: With the advent of new provisional crown materials, it has become imperative to evaluate their marginal fit and strength to select the ideal provisional crown material., Aim: The purpose of this in vitro study was to evaluate and compare the vertical marginal fit and flexural strength of provisional crowns prepared using computer-aided design-computer-aided manufacturing (CAD-CAM) temporary material versus those fabricated using bis-acrylic composite-based autopolymerizing resin material., Materials and Methods: Eighty samples were divided into two equal Groups (I and II). Group I consisted of forty samples that were evaluated for flexural strength and Group II consisted of forty samples that were evaluated for their vertical marginal fit. Group I was subdivided as Group IA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks and Group IB, i.e., CAD/CAM provisional material blocks. Similarly, Group II was subdivided as Group IIA, i.e., bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns and Group IIB, i.e., CAD/CAM provisional material crowns. Marginal adaptation was evaluated using stereomicroscope and image analyzing software to measure the amount of marginal gap. For flexural strength, all specimens were subjected to a standard compression load in the universal testing machine until fracture occurred. Data were analyzed using Student's t -test ( P = 0.001)., Results: CAD/CAM provisional crowns showed better marginal adaptation (34.34 μm) as compared to bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) crowns (63.42 μm) ( P < 0.001). The flexural strength of CAD/CAM blocks (94.06 megapascals [MPa]) was not statistically different from bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4) blocks (101.41 MPa) ( P > 0.001)., Conclusion: Protemp™ 4 and CAD/CAM provisional materials have comparable flexural strength. However, the marginal fit of temporary crowns fabricated by CAD/CAM was found to be superior to the ones fabricated using bis-acrylic composite-based autopolymerizing resin material (Protemp™ 4)., Competing Interests: There are no conflicts of interest.

Purpose: To compare and analyze trueness and precision of provisional crowns made using stereolithography apparatus and subtractive technology., Materials and Methods: Digital impressions were made using a master model and an intraoral scanner and the crowns were designed with CAD software; in total, 22 crowns were produced. After superimposing CAD design data and scan data using a 3D program, quantitative and qualitative data were obtained for analysis of trueness and precision. Statistical analysis was performed using normality test combined with Levene test for equal variance analysis and independent sample t-test. Type 1 error was set at 0.05., Results: Trueness for the outer and inner surfaces of the SLA crown (SLAC) were 49.6±9.3 µm and 22.5±5.1 µm, respectively, and those of the subtractive crown (SUBC) were 31.8±7.5 µm and 14.6±1.2 µm, respectively. Precision values for the outer and inner surfaces of the SLAC were 18.7±6.2 µm and 26.9±8.5 µm, and those of the SUBC were 25.4±3.1 µm and 13.8±0.6 µm, respectively. Trueness values for the outer and inner surfaces of the SLAC and SUBC showed statistically significant differences ( P <.001). Precision for the inner surface showed significance ( P <.03), whereas that for the outer surface showed no significance ( P <.58)., Conclusion: The study demonstrates that provisional crowns produced by subtractive technology are superior to crowns fabricated by stereolithography in terms of accuracy.

Interdental papillae regeneration remains a challenge in implant dentistry in cases in which papillae are lost following tooth extraction. This report presents an implant case with missing 1st and 2nd premolars and total papillary loss. We performed immediate provisionalization to the first premolar implant with a temporary abutment and crown, whereas the second premolar was submerged. Crown contouring and modifications to the shape and size were performed once every month (the temporary abutment and crown disconnected three times during the 3-month healing period). At the end of the 3-month healing period, papillae regeneration was observed between the implant and the adjacent tooth and between the adjacent implants. Papillae regeneration is possible with temporary abutment and a composite material crown that is properly contoured and polished, even with several abutment removals during the healing period.