Comparison of fit accuracy between conventional and CAD/CAM-fabricated band-loop space maintainers

Comparative evaluation of the clinical success of 3D-printed space maintainers and band-loop space maintainers

BACKGROUND

Exploring the integration of 3D-printing technology in space maintainer (SM) manufacturing could offer innovative solutions and insights for enhancing SMs.

AIM

To compare the clinical success, retention, and periodontal effect of traditional band-loop (TBL) SMs with 3D-printed SMs.

DESIGN

Seventy children (mean age: 6.99 ± 1.18) were divided into two groups. Laser sintering (LS) group (n = 34): Patients were scanned with an intraoral scanner. SMs were produced with LS 3D-printing method from a titanium-based metal powder. T group (n = 36): Impressions were taken with alginate. SMs were produced by adjusting the bands and soldering the wires on the model. The retention and effects on oral hygiene of the SMs were evaluated at the sixth month. Preference for impression technique was assessed by a five-question survey.

RESULTS

Thirty-eight percent of T SMs and 66% of LS SMs failed (p = .007). The mean survival time was significantly higher in the T group (p = .035). No difference was found between the initial and control full-mouth Gingival Index (GI) and Plaque Index (PI) values of the two groups. Both groups had increased GI/PI values in abutment teeth. Patients in the LS group interpreted their impression experience more positively.

CONCLUSION

It is important to provide oral hygiene education before applying fixed SMs and utilize more digital workflow in paediatric dentistry.

Clinical application of a digital semi-rigid bridge space maintainer fabricated from polyetheretherketone for premature loss of primary molars

BACKGROUND

Premature loss of primary molars can be treated with a band loop space maintainer (SM). However, fabricating a conventional band loop SM requires multiple clinical and laboratory procedures, which can potentially affect the accuracy of the SM. Moreover, the conventional SM is unable to fully restore masticatory function and maintain the vertical dimension of the edentulous space. In this current study, a fully digital workflow to fabricate a semi-rigid bridge SM made from polyetheretherketone (PEEK) has been described and evaluated for its clinical effectiveness.

METHODS

A total of 15 children (eight males and seven females) between the ages of 4-8 years, who experienced the premature loss of a single primary molar, were included in this study. Digital impressions were taken using the CEREC CAD/CAM chair system and imported into CAD software to design the semi-rigid bridge SM, which was fabricated using PEEK block as the maintainer material. The digital SM was tried-in and bonded to the abutment with resin cement. The edentulous space was measured immediately after bonding (T0) and 1 month (T1), 3 months (T2), and 6 months (T3) after treatment. The periodontal condition and mobility of the SM and abutment were also examined.

RESULTS

The use of digital impressions resulted in a decreased occurrence of the pharyngeal reflex. The digital semi-rigid bridge SM, fabricated with PEEK, was both convenient and aesthetically pleasing, and successfully restored the anatomy and masticatory function of the missing primary molar. None of the 15 semi-rigid bridge SMs or abutments became loose or fell off during the study, and only one child presented with gingivitis. Furthermore, the difference in the edentulous space at T0, T1, T2, and T3 was not statistically significant (all P > 0.05).

CONCLUSIONS

The digital semi-rigid bridge SM fabricated with PEEK was clinically effective in maintaining the missing space and had advantages over the traditional band/crown loop SM.

Longevity of Aesthetic Fixed Space Maintainers in the Anterior Area of the Pediatric Dental Patient

Space maintenance for children at very early ages in primary molars or posterior sectors is widely used and the scientific evidence is clear as to its indications. In the anterior sectors there are doubts as to whether there is a loss of space and its use is usually accompanied by aesthetic, phonatory requirements or the completion of certain habits. In this type of aesthetic anterior maintainer, there are many medium and long-term complications that can occur.

PURPOSE

To evaluate the factors determining possible complications capable of reducing the longevity of aesthetic fixed space maintainers placed due to premature loss of temporary upper anterior teeth.

METHODS

Data were collected on 100 patients of 1-5 years of age requiring fixed space maintainer placement in the upper anterior area due to caries or traumatisms.

RESULTS

Complications were recorded in the form of resin tooth fracture (in 41% of the cases), welding fracture (16%), detachments (28%), gingivitis (26%) and root resorptions (8%). Space maintainer placement in younger children (12-24 months of age) was associated with a significantly greater incidence of root resorptions (p < 0.05).

CONCLUSIONS

Within the limits of the present study, it is concluded that fixed space maintainers would be a good treatment option in patients with prematurely missing anterior teeth, though the use of temporary first molars as abutments could imply a greater risk of failure, with a lesser incidence of root resorptions. Periodic checks and adequate measures of hygiene are essential.

The effect of aging on the mechanical properties of 3-dimensional printed biocompatible resin materials used in dental applications: An in vitro study

INTRODUCTION

The mechanical properties of biocompatible printable resin materials in an intraoral environment is still being investigated. This study aimed to assess the effect of the aging process on the mechanical properties of resin samples produced by stereolithography appearance (SLA) and digital light processing (DLP) 3-dimensional printer systems.

METHODS

The cylindrical sample (4.00 × 20.00 mm) was designed by software, and the data were transformed into digital format. A DLP printer (n = 40) and an SLA printer (n = 40) carried out the printing process. The aging procedure was applied to 20 samples from each group using a thermocycling device. After the aging procedure, the samples were placed in the universal testing device for the 3-point bending test.

RESULTS

This study showed that the aging procedure decreased maximum load, bending stress, and Young's modulus values and increased maximum deflection values of the DLP group (P <0.01). However, no statistical difference was detected in the parameters compared with the SLA group except for the maximum deflection values. Furthermore, statistically significant differences were found between maximum deflection and Young's module values of SLA and DLP control and study groups (P <0.05).

CONCLUSIONS

This in vitro study revealed that the biocompatible printable resin materials produced by DLP and SLA printers had the mechanical strength to resist the values resembling the physiological occlusal forces even after the aging procedure and could produce intraoral appliances.

In vitro examination of fracture resistance of 3D-printed resin blocks in different diameters

Objectives:

The intraoral use of commercial printable polymers in dental patients is still a challenge due to the unknown physical properties of the materials. The present study aimed to comparably evaluate the maximum load and deflection values of three-dimensional-printed resin blocks in different diameters that can be used intraorally in dental patients.

Material and Methods:

Forty-five cylindrical resin blocks in diameters of 2 mm (Group 1, n = 15), 3 mm (Group 2, n = 15), and 4 mm (Group 3, n = 15) and lengths of 20 mm were designed and printed. The samples were placed in the universal testing device to conduct the 3-point bending test. According to the Shapiro–Wilk normality test results, Kruskal–Wallis and Mann–Whitney U tests were performed for the statistical analysis. The level of statistical significance was accepted as P < 0.05.

Results:

The values for the maximum load (N) and deflection (mm) in the study groups were 218.4 ± 31.9, 2.96 ± 0.86 in Group 3; 77.05 ± 61.5, 3.91 ± 0.92 in Group 2; and 19.67 ± 2.63, 4.06 ± 1.02 in Group 1, respectively. The mean values of maximum load for Group 3 were superior to Group 2 (P = 0.020) and Group 1 (P = 0.00). Group 2 revealed higher maximum load results than Group 1 (P = 0.003). The mean values of maximum deflection in Group 3 were lower compared to Group 2 (P = 0.014) and Group 1 (P = 005).

Conclusion:

The results of this in vitro study encourage the use of resin-printed intraoral appliances in place of conventional treatment modalities.