Sof-Lex Discs Research Articles

Characterization of Water Sorption, Solubility, and Roughness of Silorane- and Methacrylate-based Composite Resins

The objective of this study was to evaluate the surface roughness (SR), water sorption (WS), and solubility (SO) of four composite resins after finishing/polishing and after one year of water storage. Two low-shrinkage composites (Filtek Silorane [3M ESPE] and Aelite LS [Bisco Inc]) and two composites of conventional formulations (Heliomolar and Tetric N-Ceram [Ivoclar Vivadent]) were tested. Their respective finishing and polishing systems (Sof-Lex Discs, 3M ESPE; Finishing Discs Kit, Bisco Inc; and Astropol F, P, HP, Ivoclar Vivadent) were used according to the manufacturers' instructions. Ten disc-shaped specimens of each composite resin were made for each evaluation. Polished surfaces were analyzed using a profilometer after 24 hours and one year. For the WS and SO, the discs were stored in desiccators until constant mass was achieved. Specimens were then stored in water for seven days or one year, at which time the mass of each specimen was measured. The specimens were dried again and dried specimen mass determined. The WS and SO were calculated from these measurements. Data were analyzed by two-way analysis of variance and Tukey post hoc test (α=0.05). Filtek Silorane showed the lowest SR, WS, and SO means. Water storage for one year increased the WS means for all composite resins tested. The silorane-based composite resin results were better than those obtained for methacrylate-based resins. One-year water storage did not change the SR and SO properties in any of the composite resins.

The effectiveness of four methods for stain removal from direct resin-based composite restorative materials.

Few studies investigated the best method for removing stains from different types of resin-based composite restorations and compared them to the more recently introduced nanocomposites. This study compared the effect of four methods for stain removal from composite resins; finishing with Sof-lex disks, using pumice and brush, bleaching with 10% carbamide peroxide and 38% hydrogen peroxide. Twenty disk specimens were prepared. Specimens were immersed in a staining solution for 3weeks. The stained surfaces of five specimens from each RBC material were treated with one of the treatment procedures. Colorimetric measurements were taken using spectrophotometer prior to and after staining, and then repeated after surface treatments. Color difference values were calculated. One-way ANOVA indicated significant differences in color change of the three composite resin materials following staining. Filtek Z250 showed the least susceptibility to discoloration followed by Renamel, Filtek Supreme was the material most prone to discoloration. Two-way ANOVA and Tukey's Post Hoc showed that all stain removing procedures except polishing with pumice, were able to return Filtek Z250 to clinically acceptable color difference. While bleaching with 38% carbamide peroxide was not effective with Renamel. Only pumice and 10% carbamide peroxide were able to return Renamel to clinically acceptable color difference. Compositions of resin-based composite resins play an important role in their susceptibility to stain and their amenability to stain removal procedures. Home bleaching showed good results for the three materials, while office bleach was the least effective.

Profilometric study to compare the effectiveness of various finishing and polishing techniques on different restorative glass ionomer cements

Objective: The aim of the present study was to evaluate the effect of various finishing and polishing techniques on the surface roughness of different types of glass ionomer (GI) restorative cements. Materials and Methods: Surface roughness of conventional, resin modified and nano-ionomer cements was evaluated after different polishing regimens. Totally 20 specimens of 12 mm thick and 10 mm diameter were prepared using Teflon mold. Prepared specimens were subjected to polishing (n = 5) by Sof-Lex discs, diamond finishing points and 30-fluted carbide burs. Control specimens did not receive any polishing treatment, but mylar trip was used as matrix. Average surface roughness (Ra) in micrometers was measured using Surtronic 3 + profilometer. Results were analyzed using Kruskal-Wallis and Mann-Whitney test. Results: Control specimens (mylar strip) showed least Ra values followed by Sof-Lex disc, carbide finishing burs and diamond finishing points with all types of glass ionomer cements used in the study. Among the GIs tested, Nano-ionomer showed least Ra followed by resin-modified GI and conventional GI. Conclusion: Mylar strip produced the smoothest surface on all the GIs tested. Nano-Ionomer showed the best polish ability with least Ra values.Clinical Relevance to Interdisciplinary DentistryGlass ionomer cements (GIC) is one of the most commonly used direct restorative material used in non-stress bearing areas especially to restore cervical lesion at tooth gingival interfacePolished GIC surface reduces plaque accumulation and thus decreases the incidence of gingival inflammation and thereby prevents periodontal problemsFinishing and polishing of the GIC enhances the longevity and color stability of the restoration.

Influence of finishing/polishing on color stability and surface roughness of composites submitted to accelerated artificial aging

To assess the influence of finishing/polishing procedure on color stability (ΔE ) and surface roughness (R(a)) of composites (Heliomolar and Tetric - color A2) submitted to accelerated artificial aging (AAA). Sixty test specimens were made of each composite (12 mm × 2 mm) and separated into six groups (n = 10), according to the type of finishing/polishing to which they were submitted: C, control; F, tip 3195 F; FF, tip 3195 FF; FP, tip 3195 F + diamond paste; FFP, tip 3195 FF + diamond paste; SF, Sof-Lex discs. After polishing, controlled by an electromechanical system, initial color (spectrophotometer PCB 6807 BYK GARDNER) and R(a) (roughness meter Surfcorder SE 1700, cut-off 0.25 mm) readings were taken. Next, the test specimens were submitted to the AAA procedure (C-UV Comexim) for 384 hours, and at the end of this period, new color readings and R(a) were taken. Statistical analysis [2-way analysis of variance (ANOVA), Bonferroni, P < 0.05] showed that all composites demonstrated ΔE alteration above the clinically acceptable limits, with the exception of Heliomolar composite in FP. The greatest ΔE alteration occurred for Tetric composite in SF (13.38 ± 2.10) statistically different from F and FF (P < 0.05). For R(a), Group F showed rougher samples than FF with statistically significant difference (P < 0.05). In spite of the surface differences, the different finishing/polishing procedures were not capable of providing color stability within the clinically acceptable limits.

THE EFFECT OF FINISHING AND POLISHING SYSTEMS ON SURFACE ROUGHNESS, MICROHARDNESS AND MICROLEAKAGE OF A NANOHYBRID COMPOSITE

The aim of this study is to examine the effect of different finishing and polishing systems on the surface roughness, microhardness and microleakage of a nano-hybrid composite. The effect of four different finishing and polishing systems (Mylar-strip, Diamond finishing bur, Sof-lex disc, PoGo) were evaluated on a nanohybrid composite (Ceram-X mono, Denstply). The surface roughness was measured by profilometer, microhardness was measured by Vicker's icrohardness tester. For microleakage evaluation, class V cavities (3x4x2 mm) were prepared at cemento-enamel junction of 60 third molars. Teeth were thermocycled 500 times (5-55°C) and immersed in 0.5% basic-fuchsin for 24-hours and evaluated. The two-way ANOVA and Posthoc tests were used for surface roughness, One-way-variance-analysis and Posthoc tests were used for microhardness and microleakage was analyzed by Kruskal-Wallis and Mann-Whitney-U tests. Measured surface roughness scores listed according to the techniques as; PoGo＜Mylarstrip= Sof-lex＜Diamond bur (p=0.000), microhardness scores as; Mylar-strip=diamond bur＜Sof- Lex＜PoGo (p=0.010), microleakage scores as; PoGo＜diamond bur=Mylar-strip＜Sof-Lex (p=0.004). PoGo was found as the most successful group regarding the investigated properties. Conclusions: The findings revealed that finishing and polishing techniques have a significant effect on the surface roughness, surface hardness and marginal sealing ability of composite restorations.

The effects of finishing and polishing techniques on surface roughness and color stability of nanocomposites

ObjectivesThe aim of this in vitro study was to evaluate the effects of different finishing and polishing techniques on the surface roughness and color stability of nanocomposites. MethodsTwo nanohybrid (Grandio, Aelite Aesthetic Enamel), two nanofill (Filtek Supreme XT Dentin and Translucent), and a microhybrid (Filtek Z250) composites were used. Two hundred and eighty disc-shaped specimens were cured under a mylar strip. Seven specimens of each resin composite were randomly assigned to one of the seven polishing systems. A profilometer was used for assessing surface roughness. ΔE was calculated with a colorimeter at baseline and 48h after storage in a coffee solution. The results were analysed by two-way ANOVA and Tukey's HSD test (α=0.05). Regression analysis was used to examine the correlation between surface roughness and color stability (α=0.01). ResultsThere was no significant difference in Ra values between mylar strips and Sof-Lex polishing discs (p>0.05). The highest ΔE and Ra values were obtained from Grandio (p<0.05), and Aelite Aesthetic Enamel had the lowest ΔE values (p<0.05). The Enhance system showed the lowest color differences among all the finishing systems. The highest ΔE values were found in the composite resin groups under mylar strips and finished with diamond burs (p<0.05). ConclusionsWhile the Sof-Lex discs provided the lowest surface roughness, the Enhance Polishing system provided the most stain-resistant groups. Grandio presented the highest surface roughness and staining susceptibility after storage in coffee solution. Aelite Aesthetic Enamel, which did not include TEGDMA in its composition, showed the least discoloration. Clinical significanceThe composites with smaller filler size did not necessarily show low surface roughness and discoloration. Staining of composite resins was dependent on monomer structure, as well as surface irregularities.

Effects of polishing systems on the surface roughness of tooth-colored materials

Background/purposePolishing systems may affect the surface characteristics of the tooth-colored restorative materials. In this in vitro study, we evaluated the surface roughness of various tooth-colored restorative materials after polishing them with three different polishing systems. Materials and methodsThe tooth-colored restorative materials evaluated were conventional glass–ionomer cement, compomer, microhybrid, and nanofil composite. In total, 112 specimens (10 mm in diameter and 2 mm thick) were prepared in a metal mold using four different tooth-colored restorative materials. After the light curing and setting cycle, seven specimens from each group which received no polishing treatment were used as controls. Specimens were randomly polished with Sof-Lex disks, Poli-pro disks, and the HilusterPlus systems for 30 seconds. The mean surface roughness of each polished specimen was determined with a profilometer and examined using scanning electron microscopy. Data were analyzed using a two-way analysis of variance and Bonferroni's post-hoc multiple-comparison test, with a probability level of 0.05. ResultsAccording to the two-way analysis of variance, the type of tooth-colored materials, polishing technique, and their interactions were statistically significant (P < 0.001). The smoothest surfaces of all materials were obtained with the Mylar strip. Glass–ionomer cement demonstrated statistically significantly higher Ra values (1.36 ± 0.77) than the other restorative materials tested (P < 0.05). Compomer (0.65 ± 0.28) produced the smoothest surface and did not significantly differ from the microhybrid composite (0.78 ± 0.39; P > 0.05). No significant difference was observed between the microhybrid and nanofil composites (1.08 ± 0.83; P > 0.05). According to the scanning electron microscopy observations, the surface irregularities of the materials were consistent with the surface roughness profilometric findings. ConclusionThe effectiveness of a polishing system on the surface roughness depends on both the polishing system and restorative material.

Evaluation of the surface roughness of a standard abraded dental porcelain following different polishing techniques

Background/purposeTo evaluate the surface roughness of the metal ceramic VITA VMK 95, a standard dental porcelain used for metal-ceramic restorations. Materials and methodsGlazed ceramic blocks of VITA VMK 95 were grinded using a rugby-shaped diamond bur in order to mimic the chairside-adjustment process and then polished using two polishing techniques. Polishing was performed using Sof-Lex discs or Sof-Lex discs followed by polishing with brushes and a prophylaxis paste. To evaluate the surface roughness, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) using the Genie digital image capture system were performed. Average roughness (Ra), root mean square roughness (Rq), valley roughness (Rv), and peak roughness (Rp) were evaluated using CLSM. ResultsThe results were analyzed using one-way analysis of variance with the post hoc Tukey test at a significance level of 5%. There were statistically significant differences between the rough group and the two polished groups (P<0.05). There was no statistically significant difference between the two polished groups (P>0.05). ConclusionsAlthough the Sof-Lex discs significantly reduced the surface roughness, their use with the prophylaxis paste and polishing brushes did not cause a further reduction in the surface roughness.

Evaluation of surface roughness and hardness of different glass ionomer cements

The aim of this study was to evaluate surface roughness and hardness of a nanofiller GIC, a resin-modified GIC, three conventional GICs, and a silver-reinforced GIC. For each material, 11 spcecimens were prepared and then stored in distilled water at 37 °C for 24 h. The surface roughness of 5 specimens was measured using a surface profilometer before polishing and after polishing with coarse, medium, fine, superfine aluminum oxide abrasive Sof-Lex discs respectively. The hardness of the upper surfaces of the remaining 6 specimens was measured with a Vickers microhardness measuring instrument. All tested GICs showed lower surface roughness values after the polishing procedure. Surface finish of nanofiller GIC was smoother than the other tested GICs after polishing. This was followed by resin-modified GIC, Fuji II LC; then silver-reinforced GIC, Argion Molar, conventional GICs, Aqua Ionofil Plus, Fuji IX, and Ionofil Molar, respectively. The result of the hardness test indicated that the microhardness value of silver-reinforced GIC was greater than that of the other GICs. When the hardness values of all tested GICs were compared, the differences between materials (except Aqua Ionofil Plus with Ionofil Molar and Ketac N100 with Fuji II LC (P>.05)) were found statistically significant (P<.05). According to the results of this study, it can be concluded that the differences in the composition of GICs may affect their surface roughness and hardness.

Effects of resin luting agents and 1% NaOCl on the marginal fit of indirect composite restorations in primary teeth

ObjectiveThe purpose of this study was to provide information regarding the marginal adaptation of composite resin onlays in primary teeth previously treated with 1% sodium hypochlorite (NaOCl) (pulp irrigant) using two different resin luting agents. Material and MethodsForty extracted sound primary molars had their crowns prepared in a standardized machine and were randomly divided into 4 groups (n=10): G1 (1% NaOCl irrigation+EnForce); G2 (EnForce); G3 (1% NaOCl irrigation+Rely X); G4 (Rely X). The onlays were made with Z250 composite resin on plaster models. After luting, the tooth/restoration set was stored in 100% relative humidity at 37ºC for 24 h and finished with Soflex discs. Caries Detector solution was applied at the tooth/restoration interface for 5 s. The specimens were washed and four digital photos of each tooth were then taken. The extents of the gaps were measured with Image Tool 3.0 software. The percentage data were submitted to a Kruskal-Wallis test (α=0.05). The Relative Risk test analyzed the chance of a gap presence correlated to each group. ResultsThere were no statistically significant differences (p>0.05) among the groups. The relative risk test revealed that some groups were more apt to have a presence of gaps than others. ConclusionNeither the 1% NaOCl treatment nor the resin luting agents caused any alterations in the dental substrate that could have influenced the marginal adaptation of composite onlays in primary teeth.

Effect of finishing and polishing techniques on the surface roughness of a nanoparticle composite resin

Aim: To evaluate the surface roughness of the resin Filtek Z350 (3M ESPE) after different finishing and polishing techniques. Methods: Sixty specimens of 7x2 mm were made and distributed in 6 groups (n=10), according to the technique employed: G1 (control) – polyester strip – no finishing or polishing; G2- multi-blade burs; G3- diamond burs 3195F and 3195FF; G4- Diamond Pro Discs (FGM); G5- Sof-Lex Discs (3M ESPE); G6- Robinson bristle brushes with pumice paste for 20 s and felt disc with 2-4 µm diamond paste for 30 s. The specimens were stored in artificial saliva at 37°C for 7 days. After the finishing and polishing techniques, surface roughness (Ra, µm) was measured using Surf-Corder profilometer SE 1700. Data were subjected to one-way ANOVA and Tukey’s test at 5% significance level. Results: G3 presented the highest surface roughness mean value (0.61). G5 presented the lowest surface roughness mean value (0.15), but it was not significantly different from G1, G4 and G6. Conclusions: According to the obtained results, Z350 composite resin presented the lowest surface roughness when finishing and polishing systems were used (Sof-lex and Diamond Pro discs and Robinson bristle brush with pumice plus Diamond® felt disc with Diamond Excel® paste). The use of diamond burs (G3) resulted in the highest composite surface roughness. There was no significantly different between G1, G4, G5 and G6.

Performance of Different Polishing Techniques for Direct CAD/CAM Ceramic Restorations

This in vitro study evaluated the performance of three ceramic and two commonly used polishing methods on two CAD/CAM ceramics. Surface roughness and quality were compared. A glazed group (GLGR) of each ceramic material served as reference. One-hundred and twenty specimens of VITABLOCS Mark II (VITA) and 120 specimens of IPS Empress CAD (IPS) were roughened in a standardized manner. Twenty VITA and 20 IPS specimens were glazed (VITA Akzent Glaze/Empress Universal Glaze). Five polishing methods were investigated (n=20/group): 1) EVE Diacera W11DC-Set (EVE), 2) JOTA 9812-Set (JOTA), 3) OptraFine-System (OFI), 4) Sof-Lex 2382 discs (SOF) and 5) Brownie/Greenie/Occlubrush (BGO). Polishing quality was measured with a surface roughness meter (Ra and Rz values). The significance level was set at alpha=0.05. Kruskal Wallis tests and pairwise Wilcoxon rank sum tests with Bonferroni-Holm adjustment were used. Qualitative surface evaluation of representative specimens was done with SEM. On VITA ceramics, SOF produced lower Ra (p<0.00001) but higher Rz values than GLGR (p=0.003); EVE, JOTA, OFI and BGO yielded significantly higher Ra and Rz values than GLGR. On IPS ceramics, SOF and JOTA exhibited lower Ra values than GLGR (p<0.0001). Equivalent Ra but significantly higher Rz values occurred between GLGR and EVE, OFI or BGO. VITA and IPS exhibited the smoothest surfaces when polished with SOF. Nevertheless, ceramic polishing systems are still of interest to clinicians using CAD/CAM, as these methods are universally applicable and showed an increased durability compared to the investigated silicon polishers.

Surface roughness of the restored enamel after orthodontic treatment

After fixed appliance treatment, one concern is to restore the enamel surface as closely to its original state as possible. A variety of cleanup processes are available, but all are time-consuming and carry some risk of enamel damage. The purpose of this study was to examine tooth surfaces restored with different cleanup protocols. Ninety-nine premolars extracted for orthodontic purposes were used. The 2 materials tested were Sof-Lex disks (3 M ESPE AG, Seefeld, Germany) and fiberglass burs (Stain Buster, Carbotech, Ganges, France). These were used alone and in combination with high- and low-speed handpieces, with which they were also compared. Eight groups were ultimately tested. All groups were compared with intact enamel, which served as the control group. From each group, 10 samples were examined with profilometry and 1 with scanning electron microscopy. Adhesive remnant index scores were recorded to ensure equal distributions for the groups. The time required for the cleanup processes and profilometry test results were also recorded. The fastest procedure was performed with high-speed handpieces, followed by low-speed handpieces. Sof-Lex disks and fiberglass burs required more time than carbide burs but did not result in significantly longer times for the cleanup procedure when combined with tungsten carbide-driven low- or high-speed handpieces or when used alone with low-speed handpieces. Although Sof-Lex disks were the most successful for restoring the enamel, it was not necessary to restore the enamel to its original surface condition. Generally, all enamel surface-roughness parameters were increased when compared with the values of intact enamel. The average roughness and maximum roughness depth measurements with Sof-Lex disks were statistically similar to measurements of intact enamel. No cleanup procedure used in this study restored the enamel to its original roughness. The most successful was Sof-Lex disks, which restored the enamel closer to its original roughness.

Effects of different polishing techniques on the surface roughness of dental porcelains

ObjectiveThe purpose of this study was to evaluate the effects of different polishing techniques on the surface roughness of dental porcelains.Material and MethodsFifty-five cylindirical specimens (15x2 mm) were prepared for each feldspathic (Vita VMK 95, Ceramco III) and low-fusing dental porcelain (Matchmaker). Fifty-five specimens of machinable feldspathic porcelain blocks (Vitablocs Mark II), (12x14x18 mm) were cut into 2-mm-thick slices (12x14 mm) with low speed saw. The prepared specimens were divided into 11 groups (n=5) representing different polishing techniques including control ((C) no surface treatment), glaze (G) and other 9 groups that were finished and polished with polishing discs (Sof-Lex) (Sl), two porcelain polishing kits (NTI (Pk), Dialite II (Di)), a diamond polishing paste (Sparkle) (Sp), a zirconium silicate based cleaning and polishing prophy paste (Zircate) (Zr), an aluminum oxide polishing paste (Prisma Gloss) (Pg), and combinations of them. The surface roughness of all groups was measured with a profilometer. The data were analyzed with a 2-way analysis of variance, and the mean values were compared by the Tukey Honestly Significant Difference test (α=0.05).ResultsFor all porcelain material groups, the lowest Ra values were observed in Group Gl, Group Sl, Group Pk, and Group Di, which were not significantly different from each other (p>0.05).When comparing the 4 different porcelain materials, the machinable feldspathic porcelain block group (Mark II) demonstrated statistically significantly less Ra values than the other porcelain materials tested (p<0.05). No significant difference was observed between the VMK 95 and Ceramco III porcelain groups (p=0.919), also these groups demonstrated the highest Ra values.ConclusionSubjected to surface roughness, the surfaces obtained with polishing and/or cleaning-prophy paste materials used alone were rougher compared to the surfaces finished using Sof-lex, Dialite, and NTI polishing kit. Polishing kits and discs were found more effective than the polishing pastes used alone or combined use with Sof-lex discs, thus improving surface smoothness.

Influência do Acabamento e polimento de Cimentos de ionômero de vidro na rugosidade superficial

The aim of this study was to compare methods of polishing of Ketac-Fil plus and Vitro-Fil. Class V cavities on extracted bicuspids were restored with Ketac-fil and Vitro-Fil. Replicas in Epoxy resin of the restored teeth were analysed on an MEV and profilometer. The Sof-Lex discs produced a smoother surface without irregularities. The Enhance system associated to the Kota II paste presented a surface with a vast amount of deep irregularities with some material detaching from the surface. The study can conclude that the polishing of the ionomeric restorations modifies the surface of the restoration material.

Effect of resin-removal methods on enamel and shear bond strength of rebonded brackets.

The objective of this study is to determine (1) the effect of different resin-removal methods on shear bond strength (SBS) of rebonded brackets, (2) condition of the enamel surface, (3) time spent to remove resin remnants, and (4) the location of the bond failure. A total of 80 premolars were included in the study. Fifty of them were divided into five groups and bonded using Light Bondtrade mark sealant and Quick Curetrade mark adhesive. Ten of the samples were debonded, and the SBS of the first debonding was calculated. Forty brackets were debonded using pliers and examined by an optical microscope (16x) to determine the location of the bond failure interface, using a modified Adhesive Remnant Index (ARI). The remnant adhesives were cleaned with four methods: (1) low-speed tungsten-carbide bur (TCB), (2) high-speed TCB, (3) Sof-Lex finishing disks, and (4) microetcher. The brackets were rebonded, and a second set of SBS and ARI values were calculated and statistically evaluated. Thirty of the premolars were divided into five groups receiving the same resin-removal methods and examined by scanning electron microscope. Rebonded teeth had a greater SBS than the initial bonding, except in group 4. The rebonded SBS values were similar in groups 1-3, and only group 4 showed a statistical difference. Sof-lex discs were the most time-consuming procedures and left much adhesive remnant. The high-speed TCB was found to be the most hazardous to the enamel. The scarring of enamel after the debonding is inevitable but can be reduced.

Redução de esmalte interproximal como alternativa no tratamento ortodôntico de casos limítrofes

INTRODUÇÃO: o plano de tratamento ortodôntico deve considerar fatores como apinhamento dentário, protrusão dentoalveolar, discrepâncias maxilares e necessidade de alteração do perfil facial. Também se deve ter em mente as características de normalidade conforme a raça do paciente. Assim, buscando uma abordagem individual do paciente, em casos limítrofes, a terapia ortodôntica pode ser realizada com ou sem extrações. OBJETIVO: realizar uma revisão da literatura sobre a terapia de redução de esmalte interproximal como uma alternativa de tratamento ortodôntico sem extrações para pacientes considerados limítrofes e exemplificar a técnica a partir do relato de um caso clínico. MÉTODOS: para a execução da redução, usou-se brocas Carbide em alta rotação para a remoção do esmalte, discos Sof-Lex para o acabamento e polimento das superfícies desgastadas e aplicação tópica de fluoretos, visando aumentar a proteção do esmalte. CONCLUSÃO: concluiu-se que a técnica é indicada na resolução de discrepâncias no comprimento do arco dentário de até 8,5mm, a fim de evitar as extrações dentárias em pacientes com bom perfil facial. Preferencialmente, os dentes submetidos à técnica devem ser largos, com forma triangular e paredes de esmalte espessas.

Porcelain Refinishing with Two Different Polishing Systems after Orthodontic Debonding

To compare the effects of two polishing systems on the surface roughness of three types of porcelain after orthodontic debonding. A total of 90 porcelain discs were fabricated from feldspathic (n = 30), leucite-based (n = 30) or lithia disilicate-based (n = 30) ceramics. Ten samples in each group served as the control and received no surface treatment. The remaining 60 samples in three of the porcelain groups were bonded with lower incisor brackets and debonded using a testing machine in shear mode at a rate of 1 mm/minute crosshead speed. After debonding, the remaining adhesive resin was removed with a tungsten carbide bur. Then, two experimental subgroups (10 each) in each porcelain group were treated as follows: in the first subgroup, porcelain polishing wheel and polishing paste were applied, whereas in the second, polishing was performed using a series of Sof-Lex discs. The average surface roughness (Ra) of the all samples was evaluated using SPM/AFM (surface probe microscope/atomic force microscope). Data were statistically analyzed by analysis of variance for each porcelain material and polishing method. The polishing techniques affected surface roughness significantly. There were significant differences between the groups; higher Ra values were obtained with the use of porcelain polishing wheel and polishing paste (P < .001). The application of Sof-Lex discs can produce smoother porcelain surfaces than porcelain polishing wheel and polishing paste.

Usage of Fiber-Reinforced Resin Instruments in Interproximal Surfaces

The aim of this study was to investigate the effects of fiber-reinforced resin burs on the surface roughness of a nanofilled composite. Average surface roughness values (Ra, mum) were measured using a surface profilometer and surface textures after finishing procedures were evaluated using a scanning electron microscope (SEM). Thirty cylindrical specimens were prepared using sectional teflon molds. A nanofilled composite was chosen. After the preparation specimens were divided into three subgroups randomly. After profilometric measurements, representative samples of the mentioned finishing procedures were selected and SEM analyses were carried out. Mylar strip group was statistically different from the other two groups (P<.05). The smoothest surfaces occurred when composite resin samples were light cured against the strips. On the other hand there was no statistical difference between fiber-reinforced resin burs and Sof-Lex discs (P>.05). For fiber-reinforced resin burs scratches and pitting which may be due to plucking of the filler particles during finishing were observed on the surface topography of the composite resin material. On the other hand, for the Sof-Lex discs although scratches were noticed on the surface topography, no pitting was observed. Fiber-reinforced resin burs can be preferred for the grinding of composite surplus in interproximal surfaces, where the use of Sof-Lex discs can be harmful to soft tissues.

Effect of different splint removal techniques on the surface roughness of human enamel: a three‐dimensional optical profilometry analysis

Because there is no standard protocol for the removal of resin-based materials that retain semi-rigid trauma splints on teeth, iatrogenic enamel damage caused by various splint removal techniques has remained unknown. The purpose of this study was to evaluate the effect of five different resin removal techniques (H6/H7 scaler, ultrafine diamond bur, ultrasonic scaler, 16-blade tungsten carbide bur, and Sof-Lex disks) on the surface roughness of human enamel. Three-dimensional white-light interferometry, a non-contact profilometry technique, was used to obtain qualitative and quantitative measurements of surface roughness both at baseline and after finishing procedures. Statistical analysis using Friedman test and Wilcoxon signed ranks test showed that the roughest enamel surface was obtained after splint removal with the hand scaler (P < 0.05). Overall, the smoothest enamel surface was obtained after removal of resin with Sof-Lex disks and the 16-blade tungsten carbide bur (P < 0.05).