The association between patient's compliance and age with the bonding failure of orthodontic brackets: a cross-sectional study

Debonding Characteristic and Survival Probability of Adhesive Flash-Free Ceramic Orthodontic Brackets Following pH Cycling

OBJECTIVES

 Orthodontic bracket bond failure is an obstacle in clinical orthodontics. This study investigated the influence of pH cycling on the shear bond strength (SBS), adhesive remnant index (ARI), and survival probability of adhesive-precoated flash-free ceramic brackets.

MATERIALS AND METHODS

 Forty mandibular premolars were randomly divided into two groups (n = 20): C: noncoated orthodontic brackets, and F: flash-free adhesive-precoated orthodontic brackets. Each group was subdivided into two subgroups according to storage medium solutions (n = 10): in subgroup AS, specimens were immersed in artificial saliva for 24 hours, and in Subgroup ASL, specimens were recycled between a demineralizing solution and an artificial saliva for 42 days. Within each subgroup, specimens were subjected to SBS and ARI testing. SBS data were analyzed using one-way ANOVA (analysis of variance) and Tukey's post-hoc test. Weibull analysis was performed on the SBS data to determine the characteristic SBS and their survival probabilities.

RESULTS

 Flash-free adhesive-precoated brackets had higher significant (p < 0.001) SBS values in both the AS group (17.74 ± 1.74 MPa) and the ASL group (12.61 ± 1.40 MPa) compared with the noncoated bracket (10.67 ± 1.55 and 7.89 ± 1.39 MPa, respectively). The ARI scores for the noncoated brackets in the AS group were 70% occurrence for score 1, while 90% for score 1 in the ASL group. For the flash-free precoated brackets, ARI scores were 70% occurrence for score 2 in the AS group, while 80% for score 2 in the ASL group. Flash-free brackets had higher SBS in both AS and ASL groups (14.07 and 9.76 MPa, respectively), at 95% survival probability.

CONCLUSION

 Flash-free orthodontic brackets performed better in terms of significantly higher bond strength and higher ARI scores. Meanwhile, noncoated brackets revealed acceptable SBS results in both storage medium groups. Flash-free brackets showed higher survival than the noncoated brackets in both storage medium groups at 90% survival probability.

Orthodontic bracket failure rate after bonding with and without primer - A systematic review and meta-analysis

OBJECTIVE

To compare the difference in failure rates between orthodontic brackets bonded with light-cured primer and those bonded without primer.

MATERIAL AND METHODS

An electronic search of five databases and additional manual searches were performed until January 2024. Randomized and prospective non-randomized controlled trials directly comparing the bracket failure rate with and without primer. Two authors independently collected study characteristics by extracting outcome data from pre-defined sheets. After evaluating the risk of bias, the odds ratio and 95% confidence intervals (CIs) were calculated with random-effects models.

RESULTS

Four studies were evaluated using qualitative and quantitative analysis. The analysis included data from 199 patients (1691 brackets with primer and 1646 brackets without primer). Random effects of pooled meta-analysis demonstrated statistically significant differences in the bracket failure rates (odds ratio=1.50, p=0.010, [95% CI 1.10 to 2.05]). The risk of failure was 1.5 times greater when brackets were bonded without primer.

CONCLUSION

The results should be interpreted in the context of the limited sample size, even though there was a substantial difference in the failure rates of brackets with and without a primer, favouring the use of a primer. Furthermore, the validity of the finding may be limited by potential variables such as patient factors, clinician expertise, and isolation. More extensive research is required to validate these findings (PROSPERO CRD42024593134).

Metallic vs Ceramic Bracket Failures After 12 Months of Treatment: A Prospective Clinical Trial

INTRODUCTION

Orthodontic treatment with fixed vestibular appliances is still widely used worldwide. When choosing the aesthetic alternative of ceramic brackets, the possibility of failure and cracking of braces should be considered. Therefore, the aim of the present study was to compare the failure rates of ceramic and metal brackets in a 12-month clinical study.

METHODS

Eighty patients undergoing fixed orthodontic treatment with vestibular appliances were enrolled and divided into 2 equal groups: MET for metal brackets and CER for ceramic brackets. After bonding, bracket failures were recorded for 12 months, along with the archwire placed at the time of failure. Angle's dental class, skeletal class, Wits appraisal, Little's irregularity index, overjet, overbite, age, and gender of the patients were recorded from pretreatment cephalometric tracings and study casts. The data were statistically analysed (P < .05).

RESULTS

Significantly higher failure rates were found for ceramic brackets in the overall analysis, in the mandibular arch, and in the posterior region. Regression analysis revealed a significant influence of round nickel-titanium archwires on higher failure rates, whilst a significant influence of rectangular archwires was found on lower failure rates.

CONCLUSIONS

Ceramic brackets showed higher failure rates. Patients should be aware that orthodontic treatment with ceramic brackets may involve delays and inconvenience due to the higher failure rate compared to metal brackets.

Loss of attachments in patients during orthodontic therapy with clear aligners: A prospective clinical study

OBJECTIVE

This study aimed to assess the loss rate of attachments and investigate its probable influencing factors in patients during orthodontic therapy with clear aligners.

MATERIALS AND METHODS

A total of 55 patients treated with clear aligners were enrolled in this prospective clinical study. The loss rate of attachments was evaluated after a 6-month follow-up since the initial bonding was finished. The attachment survival curves were gone through Kaplan-Meier estimates. The Cox regression model with shared frailty was conducted to evaluate the hazard ratios (HRs) for the following factors, including sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount, arch, tooth position and attachment type.

RESULTS

There were a total of 47 patients (14 males and 33 females; and mean age: 26.77 ± 8.45) in which 722 attachments were involved in the final analysis. During the 6-month follow-up, 99 attachments were lost by 40 participants. The overall loss rate was 13.7%. The loss of attachments was more common in the early months of therapy. During the first 2 months, 71 attachments were lost. The loss rate of attachments was not significantly affected by sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount and attachment type (P > 0.05). The loss rate of mandibular attachments was 1.8 times that of maxillary attachments (HR = 1.8; 95% CI: 1.2-2.8; P = 0.009). The loss rate of molar attachments was 5.5 times that of incisor attachments (HR = 5.5; 95% CI: 1.6-19; P = 0.007).

CONCLUSION

During the first 6 months, the overall loss rate of attachments was 13.7%. In the early months of therapy, loss of attachments was more common. The loss rate decreased as treatment time increased. Loss of attachments was significantly affected by arch and tooth position, with higher loss rates in the mandibular arch and molars. Besides, loss of attachments was not affected by sex, age, dental malocclusion, vertical skeletal pattern, anterior overbite, operators, tooth extraction, attachment amount and attachment type.

Influence of Reminder on Enhancing Compliance in Patients with Fixed Orthodontic Appliance Treatment (a Randomized Controlled Clinical Trial)

Purpose

Patient compliance during orthodontic treatment has a significant effect on the aims, outcome, and duration of the treatment. The aim of this study is to evaluate the influence of reminders on enhancing orthodontic patient compliance.

Patients and Methods

Twenty-six subjects undergoing orthodontic treatment with fixed appliances were randomly assigned into two groups: control (Ct) and intervention (In) groups. The oral hygiene parameters of plaque index (PI), bleeding index (BI), and white spot lesion (WSL) with appointment adherence and bracket fracture were recorded at base line (T0), 2 months (T1), 4 months (T2), and 6 months (T3). In group participants received weekly reminders and subjects' compliances were classified into poor, fair, and excellent compliance.

Results

Statistically significant differences were found in PI level at T2 between Ct and In groups (p-value = 0.006), whereas a non-significant difference was found for BI (p-value>0. 05). There was a statistically significant increase in WSL for the Ct group across the study time points (p-value = 0.03), while no significant change in WSL was detected for the In group (p-value>0.05). The compliance levels of In and Ct groups were excellent and fair, respectively.

Conclusion

The study suggests that weekly reminders can enhance the oral hygiene status in patients with orthodontic appliances (POA) and elevate the level of compliance to excellent.

Registration number

ClinicalTrials.gov NCT05331820.

Knowledge, attitude, and awareness on the protocols and trends in orthodontic retention among dental students

This survey aimed at evaluating the knowledge and awareness regarding the various retention protocols used in orthodontic practice. A survey has been conducted among the dental students by circulating 15 close-ended questions online to analyze the data collected on the protocols and trends in orthodontic retention. The male and female distribution among the study population was evaluated, and the retention protocols used were computed; statistical analysis was performed using SPSS software. Ninety-four percent accepted that Hawley retainers are predominantly used compared to fixed retainers. Eighty-seven percent agreed that they aim at a more stable dentition by the completion of orthodontic treatment. The Chi-square test on the knowledge of respondents on the permanent retention to be followed after orthodontic treatment to close generalized spacing is statistically not significant, P = 0.056. Within the considered limitations, it is clear that there is awareness among the dentists regarding the use of a retention appliance to ensure stability at the finish of orthodontic treatment. But the protocol for the same remains variable. Further studies can be performed to identify the effectiveness of each of the different retention protocols and their indications in various cases.

Effect of different enamel pretreating agents on bonding efficacy and survival rates of orthodontic brackets: In vitro study and split-mouth randomized clinical trial

INTRODUCTION

This double in vitro study and randomized clinical trial aimed to investigate the bonding failure rates of orthodontic brackets after enamel pretreatment with agents showing different particle sizes.

METHODS

For the in vitro study, 80 bovine teeth were randomly divided into 4 groups according to the pretreating method used and their particle sizes: erythritol (14 μm), glycine (18-22 μm), sodium bicarbonate (70 μm), and no pretreatment. Scanning electron microscopy microphotographs were performed after pretreatment. Then, brackets were bonded, and shear bond strength was calculated. For the clinical study, agents with low (erythritol) and high (sodium bicarbonate) particle sizes were chosen. Twenty consecutive patients willing to start fixed orthodontic treatment with vestibular stainless steel brackets were enrolled. Patients were randomly divided into 2 groups following a split-mouth design. Group A underwent a 5-second enamel pretreatment procedure with erythritol for teeth belonging to maxillary left and mandibular right quadrants, whereas the remaining quadrants were pretreated for 5 seconds with sodium bicarbonate powder. In group B, quadrants were inverted. Then, brackets were bonded on the vestibular surfaces of teeth, and patients were visited monthly for 12 months to assess bond failures. Periodontal evaluation of probing pocket depth, bleeding on probing, plaque index, and papilla bleeding index was conducted before bonding and after 1, 3, 6, and 12 months.

RESULTS

The in vitro study showed that erythritol and control presented significantly higher shear bond strength values for other agents. Bicarbonate showed the lowest values. In the clinical study, 20 patients (aged 16.4 ± 3.9 years) were enrolled, and all completed the study. Erythritol showed a significantly lower failure rate (3%) than sodium bicarbonate (7.5%). Kaplan-Meier survival plots showed statistically significant differences in risk of failure between the 2 groups during the 12-month follow-up.

CONCLUSIONS

Enamel pretreatment with erythritol can be a viable technique to reduce failure rates of orthodontic brackets.

REGISTRATION

The trial was not registered.

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

No funding or grant was received for this research.

Bracket Failure in Orthodontic Patients: The Incidence and the Influence of Different Factors

Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. Methodology. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. Results. A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. Conclusion. The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.

Residual Adhesive Removal Methods for Rebonding of Debonded Orthodontic Metal Brackets: Systematic Review and Meta-Analysis

Debonding of orthodontic brackets is a common occurrence during orthodontic treatment. Therefore, the best option for treating debonded brackets should be indicated. This study aimed to evaluate the bond strength of rebonded brackets after different residual adhesive removal methods. This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, The Cochrane Library, SciELO, Scopus, LILACS, IBECS, and BVS databases were screened up to December 2020. Bond strength comparisons were made considering the method used for removing the residual adhesive on the bracket base. A total of 12 studies were included for the meta-analysis. Four different adhesive removal methods were identified: sandblasting, laser, mechanical grinding, and direct flame. When compared with new orthodontic metallic brackets, bond strength of debonded brackets after air abrasion (p = 0.006), mechanical grinding (p = 0.007), and direct flame (p < 0.001) was significantly lower. The use of an erbium-doped yttrium aluminum garnet (Er:YAG) laser showed similar shear bond strength (SBS) values when compared with those of new orthodontic brackets (p = 0.71). The Er:YAG laser could be considered an optimal method for promoting the bond of debonded orthodontic brackets. Direct flame, mechanical grinding, or sandblasting are also suitable, obtaining clinically acceptable bond strength values.

Comparison of the failure rate, bonding time and ARI score of two orthodontic bonding systems: Self-Etch Primer and Conventional Etching Primer: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the failure incidence of brackets with at least six months follow-up between self-etch primer and conventional etch/primer, as well as to investigate the clinical duration of the bonding process and the amount of adhesive remnant index (ARI).

METHODS

Electronic search was conducted in databases including PubMed, Scopus, Web of Science, ProQuest, ClinicalTrials.gov, and ICTRP (International Clinical Trials Registry Platform). The electronic search targeted only randomized clinical trials and was limited from January 2000 to June 2021. Delphi list is used to evaluate the risk of bias and Stata Version14.2 software was used. This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recorded on the Ethics Committee of Research Institute of Dental Sciences, SBMU (IR.SBMU.DRC.REC.1398.240).

RESULTS

Out of 2288 extracted studies, 30 of them entered the full-text evaluation process. According to the inclusion criteria, 15 studies entered this systematic review. Containing 607 participants and 10,563 brackets/teeth. All the included studies were of randomized clinical trials (RCT) design with either parallel or split-mouth design. Comparing the two groups, the risk difference effect (RD)=0.007 CI 95% (-0.004,0.018) indicated a neglectable difference in the risk of bracket failure during treatment between the two groups. The index I²=53.9% indicated moderate heterogeneity in the results. Furthermore, the P-value=0.007 indicated statistical insignificance between the two interventions in terms of failure rate. The clinical duration of bonding time analysis were equal to SMD _Cohen=-2.67 CI95% (-3.49, -1.85), which indicated a statistically significant reduction in clinical process time, using the self-etch primer. Data synthesis for adhesive remnant index could not be conducted due to heterogeneity among included studies.

CONCLUSIONS

There was no difference between the self-etch primer and conventional etch/primer in bracket debonding at a medium level of evidence, However, there was statistically significant reduction in clinical bonding time using self-etch primer.

Assessment of preparation time and 1-year Invisalign aligner attachment survival using flowable and packable composites

OBJECTIVES

To compare preparation time and 1-year Invisalign aligner attachment survival between a flowable composite (FC) and a packable composite (PC).

MATERIALS AND METHODS

Fifty-five participants (13 men and 42 women, mean age ± SD: 24.2 ± 5.9 years) were included in the study. Ipsilateral quadrants (ie, maxillary and mandibular right, or vice versa) of attachments were randomly assigned to the FC group (Filtek Z350XT Flowable Restorative) and the PC group (Filtek Z350XT Universal Restorative) by tossing a coin. The primary outcome was preparation time. The secondary outcome was time to the first damage of an attachment. Preparation times were compared using the paired t-test, and the survival data were analyzed by the Cox proportional hazards model with a shared frailty term, with α = .05.

RESULTS

The preparation times were significantly shorter with the FC (6.22 ± 0.22 seconds per attachment) than with the PC (32.83 ± 2.16 seconds per attachment; P < .001). The attachment damage rates were 14.79% for the FC and 9.70% for the PC. According to the Cox models, attachment damage was not significantly affected by the attachment material, sex, arch, tooth location, attachment type, presence of overbite, or occurrence of tooth extraction.

CONCLUSIONS

The use of a FC may save time as compared with the use of a PC. With regard to attachment survival, there was no significant difference between the two composites. None of the covariates of attachment materials (sex, arch, tooth location, attachment type, presence of overbite, oir occurrence of tooth extraction) affected attachment damage.

Factors Influencing Patient Compliance during Clear Aligner Therapy: A Retrospective Cohort Study

Compliance is highly relevant during clear aligner therapy (CAT). In this retrospective cohort study, we assessed compliance and associated covariates in a large cohort of CAT patients. A comprehensive sample of 2644 patients (75.0% females, 25.0% males, age range 18–64 years, median 27 years), all receiving CAT with PlusDental (Berlin, Germany) finished in 2019, was analyzed. Covariates included demographic ones (age, gender) as well as self-reported questionnaire-obtained ones (satisfaction with ones’ smile prior treatment, the experience of previous orthodontic therapy). The primary outcome was compliance: Based on patients’ consistent use of the mobile application for self-report and aligner wear time of ≥22 h, patients were classified as fully compliant, fairly compliant, or poorly compliant. Chi-square test was used to compare compliance in different subgroups. A total of 953/2644 (36.0%) of patients showed full compliance, 1012/2644 (38.3%) fair compliance, and 679/2644 (25.7%) poor compliance. Males were significantly more compliant than females (p = 0.000014), as were patients without previous orthodontic treatment (p = 0.023). Age and self-perceived satisfaction with ones’ smile prior to treatment were not sufficiently associated with compliance (p > 0.05). Our findings could be used to guide practitioners towards limitedly compliant individuals, allowing early intervention.

Orthodontists' and patients' perceptions regarding techniques to reduce the orthodontic treatment duration

BACKGROUND

The purpose of this study was to evaluate patients' and orthodontists' perspectives on knowledge of techniques for reducing orthodontic treatment time and acceptance of these techniques.

METHODS

A total of 200 individuals were interviewed and equally divided into two groups: orthodontist group (62 female and 38 male; mean age, 38.07 years) and patient group (52 female and 48 male; mean age, 22.61 years; in the active stage of fixed orthodontic treatment). One questionnaire for each group was administered, including questions about the duration of orthodontic treatment and techniques used for treatment optimization, such as corticotomy, distraction osteogenesis, vibration, and laser therapy. The associations between variables were analyzed by the χ² test at a significance level of 5%.

RESULTS

Among orthodontists, 76% knew at least one technique to reduce the treatment duration, with corticotomy being the most frequently cited (66%); however, only 12% used one or more of these techniques. Laser therapy was the most frequently implemented technique (7%). Regarding the duration of orthodontic treatment, the mean time reported by orthodontists was 19 to 24 months, regardless of the technique or the experience of the orthodontist. Furthermore, 39% of patients expected their treatment to last for more than 24 months, with 50% accepting to undergo further procedures to reduce this duration.

CONCLUSIONS

Patients are willing to undergo additional procedures to reduce the treatment duration and to bear additional costs. However, despite their knowledge, orthodontists do not apply or offer these techniques to the patients.

Assessment of cooperation and compliance in adult patients at three stages of orthodontic treatment at a tertiary care hospital: A cross-sectional study

OBJECTIVE

The study was conducted to assess cooperation and compliance in adult orthodontic patients during the leveling and alignment, space closure/molar correction and finishing stages of orthodontic treatment.

MATERIALS AND METHODS

This cross-sectional study was conducted on adult patients undergoing fixed orthodontic mechanotherapy in a tertiary care hospital. Patient cooperation was assessed during orthodontic treatment stages using Orthodontic Patient Cooperation Scale (OPCS) and compliance by Clinical Compliance Evaluation (CCE) form. A sample size of 38 subjects was included for each stage of treatment; therefore, a total of 114 subjects were recruited for the study. Shapiro-Wilk test identified that the data were normally distributed. One way ANOVA was used to evaluate the percentage cooperation and compliance among three stages. Pair-wise comparisons among the three stages were performed using Post hoc Tukey test. Simple and multiple linear regression analysis were carried out to see the factors associated with cooperation and compliance.

RESULTS

A statistically significant difference was seen for scores of patient cooperation and compliance using CCE (P=0.01); however, the results of the OPCS were non-significant among the three stages of treatment (P=0.16). There was a significant difference in patient cooperation and compliance between space closure/molar correction and finishing stage (P=0.01). A highly significant decline in oral hygiene was found with the progression of orthodontic treatment, from space closure/molar correction to the finishing stage of treatment (P<0.001).

CONCLUSIONS

Improvement in the cooperation and compliance levels for adult orthodontic patients was observed during the space closure/molar correction stage, which then showed a decline as the treatment progressed. Maintenance of oral hygiene was gradually reduced with the progression of orthodontic treatment.

Mean Shearing Stroke Frequency of Orthodontic Brackets under Cycling Loading: An In Vitro Study

Based on the development of many adhesive systems and bonding techniques, bonding strength of orthodontic brackets has become even more important in modern clinical orthodontics. The aim of this study was to determine mean shearing stroke frequency of different orthodontic bracket types and bonding agents under cycling loading. Therefore, 10 different types of orthodontic bracket from 4 different brands were divided into 2 groups. Two different adhesives, namely Transbond™ XT etch-and-rinse for Group 1 and Transbond™ Plus self-etching-primer adhesive for Group 2 were considered. The brackets were tested under cycling loading force of 10-N and a crosshead speed of 300 mm/min and 40 cycle/min. The frequency of strokes that the brackets failed were determined and these data were analyzed by statistical analysis using an independent sample t-test and one-way analysis of variance (ANOVA). The level of significance was set at p < 0.05. Generally, differences between the frequency of shearing strokes of the bracket failures were found to be statistically significant depending on the type of adhesives and brackets (p < 0.05). The bonding technique for Group 1 was found to have a significantly higher shear bonding strength than Group 2. It is also seen that different types of bracket belonging to the same or different brands had different shear bonding strength. It may be concluded that: (i) all bracket types used in this study can be applied with both bonding techniques, (ii) in order to minimize the risk of hard tissue damage, ceramic brackets should be carefully bonded using the self-etching primary adhesive technique.

Comparison of the Effects of Photobiomodulation with Different Lasers on Orthodontic Movement and Reduction of the Treatment Time with Fixed Appliances in Novel Scientific Reports: A Systematic Review with Meta-Analysis

Background: The duration of orthodontic treatment is one of the most important aspects considered by patients. Photobiomodulation (PBM) depends upon the exposure of the tissue to particular, therapeutic wavelengths of light in the "therapeutic window" (from 600 to 1200 nm). PBM increases cell metabolism, which leads to higher ATP production. Increasing the amount of ATP in well-vascularized bone cells promotes cell proliferation and differentiation, creating a favorable environment for tooth movement. Objective: The aim of the study is to discuss and compare the use of PBM in accelerating the orthodontic movement and reducing the time of treatment. Materials and methods: A systematic review was conducted. Literature searches were performed using Medline (PubMed), Web of Science, and Scopus (from September 13 to September 20, 2019). The quality assessment was performed using the Jadad scale for reporting randomized controlled trials for randomized clinical trial and randomized control clinical trial studies, and the Newcastle/Ottawa Quality Assessment Form for case/control studies. Results: Thirty-three articles from PubMed, 46 from Scopus, 5 from Web of Science were selected. After removal of duplicates, 82 articles were analyzed. Subsequently, 74 articles were excluded because they did not meet the inclusion criteria. The remaining eight articles were included in the qualitative synthesis. Conclusions and summary: PBM is an efficient, effective, and noninvasive method to accelerate orthodontic tooth movement. PBM should be introduced into the daily practice of treating various malocclusions as an additional procedure. Intraoral application gives better results and its introduction to treatment seems more reasonable.

Space Regaining Made Easy: The Case of a Severely Infraoccluded Primary Molar

Infraocclusion of deciduous molars is a quite common but challenging clinical situation that a paediatric dentist has to face in his everyday practice. This anomaly can lead to space loss, eruption disturbances of the permanent successor, and deformation of the occlusal plane. A case of a severely infraoccluded primary molar is presented. The treatment was carried out using a compressed NiTi wire applied only to the adjacent teeth. In three months, the space was recovered, and the infraoccluded temporary molar was extracted. After one year, the permanent successor erupted without any complication. The technique presented can be considered minimally invasive, and it involves cost- and time-efficient mechanics.

Shear bond strength of a flash-free orthodontic adhesive system after thermal aging procedure

Background

The aim of this study was to compare the shear bond strength (SBS) of a flash-free and precoated orthodontic adhesive with a compomer orthodontic adhesive before and after thermocycling. The adhesive remnant index (ARI) was also determined for both adhesives.

Material and Methods

The adhesive remnant index (ARI) was also determined for both adhesives. Material and Methods: A total of 120 human premolars were randomly divided into two groups (n=60) according to the orthodontic adhesive used: APC Flash-Free Adhesive Coated Appliance System (APC FF) or Transbond PLUS Color Change Adhesive (TP), as control. A SBS test was performed and ARI value for each specimen was also assessed. Results were analyzed by two-way ANOVA and Tukey's Chi-square test (p<0.05).

Results

SBS values were significantly influenced by thermocycling (p<0.01). Neither the orthodontic adhesive nor the interaction between adhesive and thermocycling statistically affected SBS results (p>0.05).

Conclusions

APC FF and TP showed similar bond strength results. Thermocycling induced a significant decrease in SBS values for the two adhesives tested, without differences between 10,000 and 20,000 thermal cycles. Moreover, APC FF left less adhesive remnants on the enamel compared to TP. Key words:APC Flash-Free, APC cement, aging, orthodontics, resin cements.