Spectrophotometric assessment of the color stability of composite resins polished with different techniques.

This study aimed to use spectrophotometry to assess the color stability of composite resins polished with different polishing techniques and scanning electron microscopy (SEM) to evaluate the surface micromorphology of the specimens. In this in vitro experimental study, a total of 96 disc-shaped specimens were fabricated from microfilled (Renamel Microfill, shade SB3) and nanohybrid (Estelite Sigma Quick, shade BW) composite resins in bright white shades (n = 48). Each group was randomized into 1 control and 2 experimental subgroups (n = 16): no polishing (control), polishing with aluminum oxide discs (experimental), or polishing with diamond-impregnated spiral wheels (experimental). In each subgroup, half of the specimens were immersed in a coffee solution and the other half in a tea solution for 48 hours after finishing (control) or polishing (experimental). Spectrophotometry was used to measure the color of the specimens at baseline, after finishing, after polishing (experimental groups only), and after immersion in tea and coffee. The surface micromorphology of a randomly selected specimen from each subgroup was assessed under SEM. The color change (ΔE*) of the specimens between measurements was calculated and analyzed using 1-way, 2-way, and 3-way analyses of variance (ANOVAs) and the Tukey test. Both tea and coffee caused significant color change in the composite resin specimens, with specimens immersed in coffee undergoing significantly greater color change than those immersed in tea (P < 0.001; 2-way ANOVA). The nanohybrid composite specimens polished with polishing discs had a significantly greater color change than nanohybrid specimens polished with spiral wheels (P = 0.041). The Tukey test revealed that there was no overall significant difference between the 2 polishing techniques (P = 0.505), but both of these subgroups exhibited a significantly lower color change than the control group (P < 0.001). In general, SEM did not reveal substantial differences between the 2 polishing techniques, but specimens polished by spiral wheels appeared to have a smoother surface. All polished specimens demonstrated clinically acceptable mean color change values (ΔE* < 3.5). The type of coloring agent had a greater effect on color stability than either the polishing technique or type of composite resin, with coffee causing a greater color change than tea.

Efficacy of air polishing in comparison with hand instruments and/or power-driven instruments in supportive periodontal therapy and implant maintenance: a systematic review and meta-analysis.

BACKGROUND: Supportive periodontal therapy (SPT) is the key for a stable periodontal health following active treatment. Likewise, implant maintenance is crucial following implant placement. This systematic review aimed to assess clinical outcomes, patients' perception, and cost-effectiveness of repeated periodontal therapy with air polishing devices (APDs) in comparison with hand instruments and/or power-driven instruments (conventional interventions) in SPT and implant maintenance. METHODS: Electronic search for randomised controlled clinical trials with minimum 6 months follow-up for SPT and implant maintenance programme was conducted for data published from 01 January 2000 to 30 April 2020 using multiple databases and hand searching. Risk of bias was assessed using the Revised Cochrane Risk-of-Bias tool (RoB 2). RESULTS: A total of 823 articles were screened. 4 SPT and 2 implant maintenance studies were eligible for inclusion. For SPT, repeated APDs interventions revealed no statistically significant difference when compared to the conventional interventions (weighted mean difference [WMD] 0.11 mm, p = 0.08). Likewise, no statistical difference was noted in terms of percentage of bleeding on probing (BOP) and clinical attachment level (CAL) gain. APDs were associated with lower pain score (based on Visual Analogue Scale) and higher patient acceptance in SPT studies. For implant maintenance, APDs resulted in reduction in PPD and percentage of BOP. However, CAL gain was comparable between the two groups. In terms of patient reported outcomes, no implant maintenance studies recorded any forms of patient reported outcomes. In addition, no studies reported on economic evaluation of APDs in both SPT and implant maintenance. CONCLUSION: Within the limitations of this systematic review and meta-analysis, repeated subgingival debridement using APDs in SPT resulted in similar clinical outcomes but better patients' comfort when compared to the conventional interventions. For implant maintenance, there is limited evidence to show that repeated application of APDs leads to improved clinical outcomes when compared to conventional treatments.

Clinical outcomes of performance of dental students using erythritol powder by means of air polishing with ultrasonic debridement with students' assessment: Part II.

OBJECTIVE: Assessment of a dental student's clinical performance is essential for providing feedback for improving education. This study evaluated the ability of undergraduate dental students to treat periodontal patients with two techniques, ultrasonic debridement with polishing (UD+P) and the erythritol powder air polishing with ultrasonic instrumentation (EPAP+UD) in a split-mouth design. METHODS: The study was conducted on undergraduate students with patients suffering from gingivitis and stage I periodontitis with grade A. The evaluation consisted of two parts: first, assessment of the student by clinical indices (full mouth plaque index (FMPI), calculus index (CI), remaining calculus index (RCI), modified gingival index (MGI) and papillary bleeding index (PBI)) at baseline, immediately and after 2 weeks. In addition to assessing treatment time for each student; and second, obtaining student feedback about the two methods used. RESULTS: Five undergraduate fourth years' students, and thirteen patients participated. Statistically significant decreases in FMPI, CI, MGI and PBI between baseline and 2 weeks post-treatment were noted in both test and control groups. At 2 weeks of inter-group comparisons, there was a statistically significant difference in FMPI and MGI indices, and immediately after the treatment, there was also a significant reduction in FMPI and CI. Treatment time was significantly less for the EPAP+UD method, and it got 10-time method preferring in comparison with the control group (UD+P) by students. CONCLUSION: The undergraduate dental student has the capacity to treat the periodontal patient using both approaches with a preference for the EPAP+UI approach over UI+P. In addition, this EPAP+UI is a promising method of education.

Assessment of the influence of selected electrolytic polishing process parameters on the surface roughness of casts made of the CoCrMo alloy.

BACKGROUND: To fabricate some prosthetic restorations, such as metal alloy frameworks for removable partial dentures (RPDs), casting techniques must be used. The penultimate stage of the cast finishing procedure is electropolishing. OBJECTIVES: The aim of the study was to assess the influence of selected electrolytic polishing process parameters on the resulting surface smoothness of the cobalt-chromium-molybdenum (CoCrMo) alloy. MATERIAL AND METHODS: The CoCrMo alloy, 3 experimental and 2 name-brand electrolytes, were used in the study. A total of 25 samples, 63 mm × 10 mm × 1 mm in size, were cast using the Nautilus® equipment. The cast samples were shaped using metal cutters and carborundum stones and separators, and were sandblasted. The prepared samples were placed in an electrolysis cell as an anode. For each sample, measurements were made by changing the potential of the electrode by 0.2 V in the range from 1.2 V to 7.0 V. The surface of the samples was analyzed using a profilometer. An optical microscope and a scanning electron microscope (SEM) were used to examine the structure of the surface. RESULTS: An analysis of the obtained results showed no statistically significant differences between the BEGO Wirolyt® electrolytic polishing liquid (WB) and experimental electrolytes K15, K8 and K13, all of which were significantly better than the Dentaurum Electrolyt® polishing solution (ED). The microscope images indicated differences in the surface structure of the samples; in the SEM images, inclusions were also visible. CONCLUSIONS: The experimental electrolytes did not differ in quality from one of the name-brand electrolytes and were even better than the other one. The obtained surface roughness values (Ra) did not differ significantly from those achieved by other researchers.

Subjective qualitative assessment of the finish line of prosthetic preparations submitted to different finishing instruments.

STATEMENT OF PROBLEM: Different instruments have been developed to improve crown finish lines after conventional preparation with diamond rotary instruments. However, more evidence on the effectiveness of these instruments is required. PURPOSE OF STUDY: The purpose of this in vitro study was to assess the effectiveness of 4 different instruments used for cervical margin finishing in regard to the external line angle (ELA). MATERIAL AND METHODS: Forty-eight freshly extracted third molar teeth with similar dimensions were conventionally prepared for crowns and randomly allocated into 4 groups (n=12) according to the finishing instrument: hand trimmer (HT), tungsten carbide bur (TCB), ultrasonic instrument (UI), and diamond rotary instrument (DRI) mounted in a contra angle handpiece with reduced speed. Photomicrographs from the margin profiles of each tooth were obtained with scanning electron microscopy (×40) before and after finishing procedures. The images were qualitatively analyzed (scores 1-4) by 9 experienced dental professionals. Average results were assessed with the paired t test and repeated measures ANOVA followed by Tukey HSD test (α=.05). RESULTS: HT, TCB, and UI demonstrated no significant differences between unfinished and finished mean ELA scores. DRI was the only group to demonstrate a significantly improved ELA (P<.001). Except for HT in relation to TCB (P=.989), all the other groups demonstrated statistically significant different ELA scores. CONCLUSION: DRI mounted in a contra angle handpiece was the only finishing instrument capable of significantly improving the ELA, while TCB and UI produced nonsignificant improvement, and HT was detrimental to the ELA.

Bonded functional esthetic prototype: an alternative pre-treatment mock-up technique and cost-effective medium-term esthetic solution.

As the economy has receded in recent years, many patients have been inclined to reject dental treatment beyond what they feel is the minimal amount necessary. Increasingly, there has been reluctance to take on the expense of full-mouth restorations and time-consuming procedures. Consequently, clinicians can benefit from innovative, conservative, interim solutions that enable them to provide segment treatment with long-term stability and esthetics, with lower initial cost. The bonded functional esthetic prototype (BFEP) allows fabrication of up to 14 teeth from composite in 1 hour, providing either a pre-treatment restoration or a long-term provisional solution until further treatment can be completed. As demonstrated herein, the BFEP enables superb function, stability, and esthetics in the interim while dispersing the cost of definitive treatment over time.

Performance assessment of Vita Easy Shade spectrophotometer on colour measurement of aesthetic dental materials.

Four different shades were used to produce 20 samples of resin-based composite and 20 samples of porcelain to evaluate the performance ability of an intra oral test spectrophotometer compared to a reference spectrophotometer. The absolute colour coordinates CIELAB values measured with both spectrophotometers were significantly different (p < 0.001). However, a high correlation was found (p < 0.001) despite the low concordance noticed. The colour difference deltaE* values calculated between different shades also were significantly different between both spectrophotometers (p < 0.05). Therefore, the Easy Shade can be used in dental practice and dental research with some limitations.

Teaching of direct posterior resin composite restorations in UK dental therapy training programmes.

AIM: With the numbers of dental therapists involved in the delivery of dental care within the UK on the increase, and the trend towards the use of direct resin composites (composites) for the restoration of posterior teeth, this study was undertaken to describe the teaching of posterior composites in dental therapy training programmes in the UK. A secondary aim was to identify differences in techniques for posterior composites taught within these dental therapy training programmes. METHODS: In 2008/9, a questionnaire seeking information on the teaching of posterior composites was distributed by email to 13 centres with dental therapy training programmes in the UK. This questionnaire sought information relating to the teaching of direct posterior composites to dental therapy students, including the amounts of preclinical and clinical teaching in respect of deciduous and permanent teeth, numbers of restorations placed, contraindications to placement, and details in respect of operative techniques. RESULTS: Ten completed responses were received (response rate = 77%). In ten programmes, student dental therapists received clinical training in the placement of composite restorations in the occlusal surfaces of premolar and permanent molar teeth, and nine programmes included such training for two and three surface occlusoproximal restorations. The mean proportions of posterior restorations placed clinically by the trainee dental therapists in permanent teeth using dental amalgam and composite were 52% and 46% respectively (range: amalgam = 20-95%; composite = 5-70%). CONCLUSION: With the exception of one programme, the teaching of posterior composites is a well established element of dental therapy training. Some variations were noted in the teaching of clinical techniques between respondent training centres. It is suggested that to ensure harmony in approaches to treatments provided by graduated therapists that training centres look to relevant consensus documents, such as those of the British Association for the Teaching of Conservative Dentistry. The findings of our study are important for the future provision of oral healthcare, given the growing evidence base in favour of minimally invasive dentistry.

Trends in dental education in the Persian Gulf--an example from Iran: contemporary placement of posterior composites.

In recent years, there has been expansion of dental education programmes from established European and North American schools into regions in the Middle East, the Persian Gulf States, and Asia. Accompanying this, there has been migration of dentists from these regions of the world to Europe and North America in the hope of finding employment or to pursue postgraduate education. Little awareness exists, however in western countries on the amount and level of clinical training provided in dental schools in which these dentists have trained. The aim of this paper is to investigate the teaching to undergraduate students in Iran of an important aspect of clinical dentistry which is showing continual development in western schools, namely the use of resin-based composites in the restoration of posterior teeth. In 2008, a questionnaire seeking information on the teaching of posterior resin-based composites was distributed by email to the person responsible for delivering teaching of operative dentistry in each of the 18 dental schools with undergraduate dental degree programmes in Iran. All 18 schools teach the placement of occlusal and occlusoproximal resin-based composite restorations in premolar and permanent molar teeth. Resin-based composites currently account for 42% of posterior direct restorations placed by undergraduates in Iran. Despite variations between dental schools being noted in the teaching of certain techniques for posterior resin-based composites, the overall extent and content of teaching of posterior resin-based composites in Iran could be described as comparable to that observed in western countries.

Teaching the placement of posterior resin-based composite restorations in U.S. dental schools.

BACKGROUND: In light of the increased use of and demand for posterior resin-based composite restorations in dental practice, the authors investigated U.S. dental schools' current teaching with regard to placement of posterior composite restorations. METHODS: In early 2005, the authors invited 52 schools to participate in an e-mailed survey. RESULTS: The authors received 47 completed responses, for a 90 percent response rate. Although all schools provided didactic and clinical teaching in the placement of occlusal resin-based composites in posterior teeth, the survey results showed variation in teaching the use of two- and three-surface occlusoproximal composites. CONCLUSIONS: The survey findings demonstrate a marked change in instruction in placement of posterior resin-based composite restorations in U.S. dental schools during the last five to 10 years. However, the authors found much variation in the nature and extent of the instruction and techniques taught. CLINICAL IMPLICATIONS: Dental schools need to ensure that their graduating students are well-prepared for independent clinical practice.

Avaliação in vitro da rugosidade superficial do amálgama em função da liga, técnica e momento de polimento / In vitro assessment of surface roughness of different amalgam varying alloy, technique and polishing time

Análise in vitro da rugosidade superficial de diferentes ligas para amálgama, em função da técnica e período de polimento. utilizou-se três ligas para amálgama: M1 - Velvalloy, M2 - Permite e M3 - Dispersalloy, duas técnicas de polimento: T1 - multilaminadas + borrachas abrasivas + pedra pomes com água e T2 - borrachas abrasivas + pedra pomes com água em dois momentos: P1 - imediato (após 15 minutos da condensaçào) e P2 - após 24 horas. Para cada condição experimental foram confeccionados 5 corpos-de-prova, utilizando-se uma matriz de teflon com um orifício central de 5mm de diâmetro de 2mm de altura, sendo realizadas quatro leituras em cada um deles num rugosímetro (Prazis). os dados foram submetidos à análise de variância (pú0,05) e teste de Tukey. As médias obtidas em micrômetros foram: para o material - M1: 0,93; M2: 0,75 e M3: 0,81; para a técnica - T1: 0,99 e T2: 0,67, e para o momento de polimento - P1: 1,05 e P2: 0,61. Concluiu-se que é necessário esperar 24 horas para realizar o polimento, sendo mais indicado realizá-lo com borrachas abrasivas e pedar pomes com água. As ligas ricas em cobre apresentaram melhores resultados que a liga convencional

Practical posterior composites. Efficient placement and predictable results.

Certainly, we could spend more time matching shades, applying characterizations, placing secondary anatomy, and even finishing. However, if posterior composite restorations are to be a viable alternative to amalgam in appropriate cases, we must accomplish efficient and predictable placement so that fees for the two types of restorations are somewhat in line. Contact must be solid, sensitivity must be kept to a minimum, and placement and finishing must be fairly simple and organized. If the problems with posterior composites aren't kept to a minimum, all of dentistry will suffer. Our contacts are excellent most of the time, but occasionally we need to redo a "light" one. Our best estimate is that about one in 100 fillings that had no preoperative symptoms needed some postoperative care after restoring. Usually these complaints are corrected by occlusal adjustment, and very rarely by replacing the restoration. We have not yet made a perfect restoration in our practice--we are still trying.

[Assessment of superficial roughness of 3 composite resins treated with different polishing techniques]. / Avaliação da rugosidade superficial de três resinas compostas submetidas a diferentes técnicas de polimento.

In this study, the superficial roughness of two composite resins classified as condensable and of a traditional hybrid composite resin was analyzed after different polishing techniques. Test specimens were confected, immersed in distilled water for 24 hours and submitted to two different techniques of superficial treatment, in which disc systems (Sof-Lex and Super Snap) and silicon tips (Enhance) were utilized. The results revealed the greater superficial roughness of Alert, when compared with Solitaire and Degufill Mineral--no statistically significant differences were observed between the last two materials. The superficial roughness of the specimens polished with Enhance tips was greater than that of the specimens polished with discs and there were no statistically significant differences between both disc systems.

Teaching of posterior resin-based composite restorations in Brazilian dental schools.

OBJECTIVE: The purpose of this study was to evaluate the teaching program of Class I and Class II resin-based composite (RBC) restorations in Brazilian dental schools and to observe if any differences were found from similar surveys conducted in North American, European, and Japanese dental schools. METHOD AND MATERIALS: A questionnaire containing 15 questions was distributed to 92 Brazilian dental schools, and 64 (70%) schools returned the questionnaire. The questions inquired the amount of time the curriculum dedicated to teaching of posterior RBC restorations, future expectation regarding the teaching time, limitation in extension of the occlusal width and the proximal box in Class II, contraindications for placing posterior RBC restorations, protocol for using bases and liners, brand of bonding agents and RBC used, instruments and techniques employed for finishing, cost relative to amalgam restorations, and biologic reactions related to the use of posterior RBC. The responses were calculated as percentages based on the number of schools that responded to the questionnaire. Where appropriate, the Chi-squared test and the Fisher exact test were used for statistical analysis. RESULTS: Of the dental schools that responded, 88% dedicated 10% to 50% of the teaching time in operative dentistry to posterior RBC restorations. A significant correlation (P = 0.041) was found between the percentage of time dedicated to the teaching of posterior RBC restorations and the higher cost of posterior RBC compared to amalgam restorations. Resin-based composite restorations cost 30% to 70% more than amalgam restorations in the 40% of dental schools that charged a fee. Posterior composites for large restorations in molars were used by 14% of the dental schools. Base and liner were not placed by 10% of dental schools in deep Class I or Class II RBC restorations. One school did not recommend acid etching of the dentin. CONCLUSION: No major differences were found in the teaching philosophy of posterior RBC restorations by comparing the Brazilian data to the data from similar surveys done in North America, Japan, and Europe.

Finishing techniques for amalgam restorations: clinical assessment at three years.

Use of the optimum finishing technique for an amalgam restoration may enhance the marginal integrity of the restoration and discourage its unnecessary early replacement. Two hundred and twenty-eight high copper amalgam restorations in 56 patients were evaluated, using clinical assessment criteria, up to three years after placement. Each patient had received at least one carved-only amalgam, at least one immediately finished restoration, and at least one amalgam that was polished at a subsequent appointment. Regardless of the finishing technique, the restorations exhibited similar marginal integrity up to three years after placement. Polished restorations were found to have substantially superior surface texture and less likelihood of surface discoloration. No evidence was found to support the use of immediate finishing techniques. The clinical significance of these findings, with respect to the need to polish amalgam restorations, is discussed.

Profilometer, SEM, and visual assessment of porcelain polishing methods.

Research has indicated that polishing ground porcelain is essential to control the wear of opposing occlusal surfaces and reduce the inflammation of contacted soft tissue. Five popular methods for polishing porcelain were evaluated by use of a profilometer, SEM, and normal vision. Seventy disks, 35 Biobond disks and 35 Ceramco disks, were roughened with a green stone and polished with one of the methods according to the manufacturers' directions. Brasseler, Dedeco, Dentsply, and Shofu porcelain polishing systems were suitable for restoring ground porcelain. However, clinical evaluations correlated to the profilometer and SEM readings revealed that the Brasseler system was superior for polishing Ceramco porcelain whereas the Den-Mat system was unacceptable.

[The enamel surface quality after interproximal stripping--a scanning electron microscopic assessment of different polishing procedures]. / Oberflächenbeschaffenheit des Schmelzes nach approximalem Beschleifen--Rasterelektronenmikroskopische Beurteilung unterschiedlicher Polierverfahren.

The surface features of stripped human enamel were studied with the scanning electron microscope. The efficiency of rotating diamond and polishing discs was compared with that of diamond and polishing strips in a newly developed handpiece. Interproximal stripping with fine and superfine grit diamond coated discs and strips created furrows which were 10 microns in width. At the interface between treated and untreated enamel no hard tissue damage could be observed. Under in vitro conditions the furrows resulting from stripping were almost totally eliminated by using aluminum oxide coated strips or discs in automatically driven handpieces. After 60 s of polishing with each polishing strip/disc the treated enamel surfaces were nearly smooth. Only a few isolated furrows of 1 to maximum 3 microns were detected. As a result, we can state that it is possible to produce surfaces which are smoother than untreated natural enamel with the rotating or the oscillating polishing procedure.

A comparison of different techniques for finishing and polishing amalgam.

Three different methods for finishing and polishing amalgam surfaces were studied by determining the roughness (Ra) of specimens at different stages of the procedures. Method I consisted of green stone, followed in sequence by finishing bur and pastes of pumice, powdered chalk, and SnO2. Method II was similar to method I but included brown and green Shofu polishers after the finishing bur. In method III medium and fine sandpaper and fine cuttle-paper discs were used before the pastes. A dramatic decrease in the Ra values was observed after the specimens had been ground with green stones, finishing burs, and sandpaper discs. Pumice resulted in a further reduction in Ra values. However, no significant differences in Ra values were found between the brown Shofu polisher, the fine cuttle-paper disc, and the different pastes. The lowest Ra value--that is, the highest smoothness--was obtained with green Shofu polisher.