Clear aligners are gaining more popularity, as most patients, especially adults, dislike the appearance of fixed appliances. In 1997, Align Technology© (Santa Clara, CA) released the Invisalign® system. The company used both computer-aided design (CAD) and computer-aided manufacturing (CAM) to produce its orthodontic appliances. This technology, which allows for multiple tooth movements from a single impression, introduced the clear aligner as it is now known. At the beginning, the Invisalign® system was used to treat simple tooth movement. However, as it developed, the manufacturer began using attachments and intermaxillary elastics to obtain different movements, so Invisalign® became a viable alternative to fixed appliances. Different aligner systems similar to Invisalign®, such as ClearCorrect, etc., became available on the market, and they use the same principle to obtain the desired results. This review investigated the indications and contraindications of clear aligner therapy (CAT), including its efficiency and limitations; patient comfort and acceptance; and periodontal health, root resorption, and stability. In conclusion, CAT has been improved over the last 18 years and is still being improved. The treatment results depend on the clinician’s own experience, case selection, and patient adherence. The clinician should be clear about the advantages and disadvantages of CAT, and the patient should be made aware that he/she should wear the appliance for 22–23h/day and only remove it while eating. The limitations of this study are lack of comparison between available CAT systems, the types and mechanics of movement produced by different types of attachments, and the cost.

Aims and Objectives: This cross-sectional study aimed to determine the impacts of five-year incident tooth loss on oral health-related quality of life (OHRQoL) in Southern Thai adults and the differences in OHRQoL regarding the number of teeth. Materials and Methods: The study samples included 657 dentate men and women, aged 35–65 years. The Thai version of the Oral Impacts on Daily Performances (OIDP) index was used to assess oral impacts. The number of teeth was grouped as 1–19 versus ≥20 teeth. Self-reported five-year incident tooth loss was classified as none, 1–2 teeth, or ≥3 teeth. Odd ratio (OR) and 95% confident interval (CI) were presented. All analyses were carried out using STATA software, version 13.1. Results: Approximately 22% of participants had fewer than 20 teeth. More than half (54%) of the participants had lost ≥ 1 tooth. OIDP were experienced by approximately 54% of participants, where impacts on eating were frequently reported. Adjusted multinomial logistic regression analyses showed that ≥3 lost teeth and having 1–19 retained teeth was significantly associated with the greater prevalence of oral impacts (OR = 9.80; 95% CI = 2.96–32.51). Conclusion: Tooth loss and its impacts affecting daily life were common among these study samples. The largest effect on impaired OHRQoL was presented by those with fewer teeth and a greater number of incident tooth loss during the past five years.

Aims and Objectives: This study was carried out to evaluate the effect of artificial aging on the marginal leakage of crowns and the credibility of three different luting cements in preventing marginal percolation. Materials and Methods: Thirty-six extracted intact premolars were selected for the study. Tooth preparation was carried out to receive complete cast crown. Castings were microblasted with 50 μm alumina powder. Group I was cemented with zinc polycarboxylate (Poly-F® Dentsply De Trey GmbH, Konstanz, Germany), Group II with glass ionomer (Fuji I, Fuji I GC Corporation, Tokyo, Japan), and Group III with resin-modified glass ionomer (Fuji II Plus, Fuji II Plus GC Corporation, Tokyo, Japan). The specimens in the subgroup I served as the control group and those in the subgroup II were subjected to thermocycling to simulate the intraoral conditions. They were artificially aged using artificial saliva as a medium of thermocycling, with a temperature variation of 5°C–55°C. All specimens were treated with 0.5% basic fuchsin dye for 24h. The crowns were then embedded in clear self-cure acrylic resin and sliced buccolingually. The sectioned halves were then placed under the optical vision microscope, and the depth of dye penetration in the proximal region was qualitatively evaluated. Results: The results showed the mean marginal leakage score is highly significant in thermocycled group as compared to that in non-thermocycled group. The results were subjected to one-way analysis of variance and post hoc Tukey test. It was found that artificial aging did have an effect on the marginal leakage of zinc polycarboxylate group and glass ionomer group. The resin-modified glass ionomer group, however, did not show much significant difference. Conclusion: The artificial aging did have an effect on the marginal leakage of polycarboxylate group and glass ionomer group, whereas resin-modified glass ionomer group did not show much statistical significance. Zinc polycarboxylate cement had maximum micro-leakage followed by glass ionomer cement. Resin-modified glass ionomer showed minimum leakage and can be regarded as the best cement for clinical use.

Aims and Objectives: The finishing and polishing of removable orthodontic appliances can produce acrylic dust containing methyl methacrylate, which is potentially prejudicial to health. The aim of this study was to determine the average amount of acrylic dust produced by the finishing and polishing processes involved in removable orthodontic appliance fabrication and the associated risk factors. Materials and Methods: This descriptive observational study constituted samples of 93 orthodontic appliances (62 upper orthodontic plates and 31 lower orthodontic plates) manufactured by sixth semester students of the Dental Technology Study Program, Universitas Airlangga, Surabaya, Indonesia, between February and May 2016, which satisfied the criteria. The amount of acrylic dust produced was calculated on the basis of the difference between the weight of an orthodontic plate after acrylic processing and the weight after finishing and polishing. Data were tested statistically using Kolmogorov–Smirnov test, Mann–Whitney test, and Hosmer–Lemeshow test with P value < 0.05 and performed with the Statistical Package for the Social Sciences (SPSS) software, version 24.0. Results: The results showed that the average acrylic dust produced in the fabrication of a removable orthodontic appliance was 1.23g (range, 0.29–3.54g). The average acrylic dust produced by the upper orthodontic plate (1.34g) was greater than that of the lower plate (0.94g). Results also showed that the finishing process produced more acrylic dust (0.94g) than the polishing process (0.27g). Conclusion: The acrylic dust produced by the removable orthodontic appliance production process undertaken by sixth semester Dental Technology students at Universitas Airlangga, Surabaya, Indonesia, had an average weight of 1.21g. The finishing process produced more acrylic dust in comparison to the polishing process. Students’ skill in producing orthodontic appliances and orthodontic plate design represents a major factor affecting the amount of acrylic dust produced.

Aims and Objectives: This study aimed to determine the biometric dimensions of three human permanent teeth in the occlusal/incisal-cervical and apical, buccolingual, and mesiodistal directions, and its relationship with age in adults in Shiraz, Iran. Materials and Methods: The samples included 50 upper canines, 50 maxillary first premolars, and 50 maxillary second molars, extracted from patients aged 25–55 years. Total length, crown labial surface length, crown palatal surface length, crown mesiodistal width, root length, and some other biometrical characteristics of the teeth were measured by using a Vernier caliper with 0.05-mm accuracy. The samples were divided into two age groups: patients aged below 45 years (younger adults group), and those aged over 45 years (older adults group). The data were analyzed by using independent t-test. P < 0.05 was considered as the significance level. Results: Most parameters such as the total length, crown mesiodistal and labiopalatal width, as well as the root length decreased in older adults group in all the three tested permanent teeth. Conclusion: During a lifetime, the crown length, mesiodistal, and buccolingual dimensions seem to decrease because of the physiological and pathological tooth wear. The tooth wear in a mesiodistal dimension is more frequent in posterior teeth than in the anterior ones.

Aims and Objectives: The aim of this study was to assess crack formation using two different cutting motions (rotation and reciprocation) in nickel–titanium rotary instrument. Materials and Methods: One hundred extracted human mandibular incisors were selected for this study. Before root canal instrumentation, low-speed saw (under water cooling) was used to section the tooth horizontally at 3, 6, and 9 mm from the apex of 0.1 mm. A digital stereomicroscope at ×25 magnification with a cold light source was used to observe the slices. Then all teeth were placed again inside the mold. Samples were classified according to the system used into the following groups: Group 1: negative control, Group 2: the ProTaper Next files, Group 3: a primary reciprocating WaveOne Gold file, Group 4: a small reciprocating WaveOne Gold followed by primary reciprocating WaveOne Gold file, and Group 5: OneShape rotary file. Samples were scanned by using a digital stereomicroscope to detect crack formation. Results: Apical level: WaveOne Gold (primary) group showed the highest prevalence of cracks. Middle level: OneShape group showed the highest prevalence of cracks followed by WaveOne Gold (small and primary) group. Coronal level: The five groups showed no statistically substantial difference in the presence of cracks. Conclusion: All rotary systems can lead to the crack formation.

Aims and Objectives: The aim of this study was to access the relationship between health literacy and toothbrushing practice in young adults. Materials and Methods: This cross-sectional analytical study consisted of 218 respondents: college (except dental students) and noncollege students. All respondents completed a general health literacy questionnaire using the Newest Vital Sign (NVS) and the specific health literacy (SHL) questionnaire comprising questions on access, knowledge, and attitudes on toothbrushing. Respondents’ regular toothbrushing practice was evaluated by using a video camera recording. All the analyses were performed by using the t-test, analysis of variance, Pearson correlation or Spearman rank correlation, and multiple linear regression statistical technique. Results: The mean scores of NVS and SHL were significantly different among the education groups (P < 0.001). Toothbrushing practice showed significantly (P < 0.05) correlations with gender, education, access, attitude, and SHL, but not with the NVS. The correlation of toothbrushing practice and SHL as well as access remained significant in multiple linear regression models after adjusting for gender and education (P < 0.05). Conclusion: Health literacy had a significant correlation with toothbrushing practice when measured with SHL. Access and SHL were the most influencing factors for toothbrushing practice in this study.

Aims and Objectives: The aim of this study was to evaluate two-body wear and surface roughness of two different monolithic ceramics: polymer-infiltrated ceramic (PICN) and lithium disilicate. Materials and Methods: Chewing simulator was used to investigate two-body wear (75,000 cycles, 49N, and 60 cycle/min). The tested samples were divided into two groups according to their materials; each group comprised 14 ceramic discs. Subtractive weight loss was used to statistically analyze the wear of all samples before and after chewing simulation test. Surface roughness was measured before and after chewing simulation test using three-dimensional optical profilometry. Data were collected and analyzed using analysis of variance test, and then verified by unpaired t-test. Results: Statistically significant differences were found for two-body wear, with higher mean weight loss in PICN than lithium disilicate after chewing simulation. PICN had higher mean surface roughness value than lithium disilicate after chewing simulation. Conclusion: PICN showed higher wear regarding weight loss and surface roughness changes than lithium disilicate.