CAD/CAM-based 3D-printed and PVS indirect bonding jig system accuracy: a systematic review, meta-analysis, and comparative analysis of hard and soft CAD/CAM transfer trays

BACKGROUND

The widespread use of CAD/CAM transfer trays warrants evaluation of their accuracy as compared to PVS transfer trays.

OBJECTIVES

To quantify the accuracy of CAD/CAM and PVS transfer trays, investigating any differences between soft and hard trays CAD/CAM transfer trays.

SEARCH METHODS

Eight different databases (Scopus, Web of Science, PubMed, Google Scholar, ProQuest, Embase, Cochrane Library, ClinicalTrials.gov) were searched, without restrictions, up to an end date of February 2023.

SELECTION CRITERIA

Clinical trials (randomized and non-randomized) and in vitro studies reporting average imprecision values for bracket positioning obtained by digital superimpositions of digitally planned and real positions.

DATA COLLECTION AND ANALYSIS

Data eligibility, data extraction, and risk of bias (RoB-2 and ROBINS-I) were conducted independently. The data, where possible, were synthesized and quantitatively analysed (meta-analysis of mean differences with 95% confidence intervals). The Grade of Recommendation, Assessment, Development and Evaluation (GRADE) analysis of the quality of evidence was performed. The t-test for independent samples was used to compare the transfer accuracy of hard and soft CAD/CAM transfer trays.

RESULTS

Thirteen studies were synthesized in this systematic review, and then eight studies were included in the quantitative meta-analysis. As regards linear measurements, there was a mean transfer error of 0.0752 mm (95%CI: 0.0428, 0.1076) for mesiodistal measures, 0.0943 mm (95%CI: 0.0402, 0.1484) for vertical, and 0.0815 mm (95%CI: 0.0469, 0.1160) for buccolingual. As for angular measurements, there was an average transfer error of 1.2279° (95% CI: 0.6011, 1.8548) for inclination, 0.9397° (95%CI: 0.4672, 1.4123) for angulation, and 0.8721° (95%CI: 0.4257, 1.3185) for rotation. CAD/CAM transfer trays were less accurate than polyvinylsiloxane (PVS) transfer trays, with those made of soft material being more accurate than the hard ones, except for vertical dimension. The GRADE quality of evidence ranged from very low to moderate.

CONCLUSIONS AND IMPLICATIONS

CAD/CAM transfer trays provide high bracket positioning accuracy, with soft transfer trays offering greater precision than rigid ones. Future randomized prospective trials are required to enhance the strength of the available evidence.

REGISTRATION

Prospero (CRD42023401278 number).

Evaluation of effectiveness and efficiency of fixed orthodontic treatment comparing standard and computer-aided design and manufacturing conventional bracket systems using indirect bonding for both: A retrospective study

BACKGROUND

To compare the effectiveness and efficiency of orthodontic treatment (OT) with standard versus computer-aided design and computer-aided manufacturing (CAD/CAM) indirect bonding of conventional brackets.

METHODS

This retrospective study examined two groups: standard indirect bonding group (12 males, 13 females; mean age 12.21 ± 0.52 years), and digital indirect bonding group (11 males, 14 females; mean age 12.76 ± 1.32 years), treated via a CAD/CAM indirect bonding system. Conventional brackets were used in both groups. Pretreatment and post-treatment records were acquired for all subjects. Weighted Peer Assessment Rating (W-PAR) index was used to assess the effectiveness of OT, in conjunction with five angular cephalometric measurements (ANB°, Sn-GoGn°, U1-PP°, IMPA° and FMA°) and comparatively analyzed using generalized mixed-effects models and post hoc test. Treatment efficiency was assessed in terms of the numbers of bracket repositionings, archwire bends, accidental bracket debondings, appointments and treatment months. Comparative analysis of efficiency was performed using the asymptotic Wilcoxon-Mann-Witney test. Statistical significance was set at 5%.

RESULTS

Total W-PAR and W-PAR component scores decreased significantly during treatment for both groups and in a similar way. Cephalometric measures ANB° and IMPA° significantly decreased and increased, respectively. Significantly fewer bracket repositionings, number of appointments and treatment months were recorded in group digital indirect bonding.

CONCLUSIONS

Although both methods investigated were effective to achieve good outcomes, CAD/CAM indirect bonding method increased the efficiency of OT, when conventional brackets are used.

A non-invasive system to manage impacted teeth associated with a large dentigerous cyst

A male patient aged 11 years presented a large dentigerous cyst in the lower left quadrant associated with retained deciduous lower lateral incisor and canine and impacted, unerupted corresponding permanent ones. The treatment consisted in marsupialisation and placement of a modified lingual arch that held a tube for decompression used for irrigation of the cystic cavity in a comfortable way for the patient and for the clinician.The same lingual arch was later used as an anchorage method for traction of the retained teeth. The final records showed complete resolution of the cyst and retained teeth were successfully Aligned into the oral cavity.

Combined use of F22 aligners and intermaxillary elastics in mild skeletal Class II: Two case reports

INTRODUCTION

The aim of these two case-reports is to illustrate and compare the therapeutic effects of Class II elastics in combination with F22 aligners in an adult and an adolescent patient, respectively.

CASE PRESENTATION

Two patients with a mild skeletal Class II malocclusion, associated with mild-to-moderate crowding, presented for orthodontic treatment. The first patient was 12 years old, while the second was 40 years old. In both cases, the goal was to obtain bilateral molar and canine Class I with ideal overjet and overbite, and Class II skeletal relationship improvement in the young patient as well. Both treatments were approached without extractions and using clear aligners (CAs) in combination with Class II elastics, giving the patient the opportunity to take advantage of a therapy that is both comfortable and aesthetic.

DISCUSSION

Final records of both cases demonstrate how appropriate analysis and diagnosis enable CAs in conjunction with Class II elastics to be used with considerable efficiency and efficacy for Class II treatment. In the first case, the key to success was exploiting residual jaw growth, while in the second case it was careful orthodontic digital planning.

CONCLUSION

In the presence of good patient compliance, CAs associated with Class II elastics provide satisfactory occlusal outcomes if biomechanics and digital set-up are carefully evaluated and executed and if diagnosis is appropriate.

Clinical predictors of cardiac toxicity in HER2-positive early breast cancer patients treated with adjuvant s.c. versus i.v. trastuzumab

Background

Few data are available about real-life cardiotoxicity associated with s.c. versus i.v. trastuzumab treatment of early-stage, HER2-positive breast cancer, and little is known about its predisposing factors.

Patients and methods

We retrospectively reviewed data of 363 adult patients treated with adjuvant trastuzumab for HER2-positive breast cancer. Univariate statistical analysis was performed, and a multivariable logistic model was developed to identify independent risk factors of cardiac toxicity.

Results

Within 5 years, the overall incidence of events meeting our criteria was 11.8%, and an early discontinuation of trastuzumab was recorded in 20 patients (5.5%). No cases of congestive heart failure occurred, neither multiple events per patient were observed. A total of 184 patients received i.v. and 179 received s.c. trastuzumab. Compared with the s.c. formulation, a higher cardiotoxicity rate for the i.v. administration (15.2% vs 8.4%) was found, and particularly in those patients with cardiovascular risk factors (19.3% vs 8.7%), at the univariate and multivariate analyses. Although more patients with prior anthracycline-based chemotherapy experienced cardiac events, the association of this therapy with cardiac events was not significant. The incidence of cardiac events was not influenced by anthropometric data (e.g. body mass index) or a diagnosis of diabetes mellitus. 5-year event-free survival was 91.7% in the overall population; event-free survival rates were similar between the s.c. and the i.v. groups.

Conclusion

Our study shows a more favorable safety profile of s.c. versus i.v trastuzumab administration. The use of s.c. trastuzumab could be advisable in at-risk patients.

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Few data are available about cardiotoxicity associated with s.c. versus i.v. trastuzumab and its predisposing factors.

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Our study shows a more favorable safety profile of s.c. versus i.v trastuzumab administration.

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Thus, the use of s.c. trastuzumab could be advisable in at risk patients.

Early effects of exercise training on on- and off-kinetics in 50-year-old subjects

We tested the hypothesis that, in healthy middle-aged subjects ( n=11, age 51.0 +/- 3.0 years, x +/- SD), the effects of exercise training on pulmonary O(2) uptake (VO(2)) on- and off-kinetics would appear earlier than those on peak. The subjects underwent a standard training program (combined endurance and resistance training) in a health club, and were evaluated before training ("time 0", T0), and after 7 (T7), 15 (T15), 30 (T30), 60 (T60) and 90 (T90) days of training. Breath-by-breath pulmonary O(2) uptake (VO(2)), heart rate (HR), systolic (SBP) and diastolic blood pressure, and capillary blood lactate concentration ([La](b)) were determined at rest and at each workload (w during a cycle ergometer incremental exercise test. The "heart rate x blood pressure product" was calculated as (HR x SBP). The day following the incremental test, the subjects performed three repetitions of a square-wave exercise at 50% of VO(2), for the determination of pulmonary VO(2) on- and off-kinetics. VO(2) and [La](bpeak) tended to increase with training; the increases became significant at T60 or T90. HR(peak)and (HR x SBP)(peak) were unaffected by training. The time constant of the "primary" component of the VO(2) on-kinetics (tau(2)) was 46.9 +/- 17.3 s (T0), 38.1 +/- 14.2 s (T7), 34.4 +/- 12.6 s (T15), 28.8 +/- 6.8 s (T30), 30.2 +/- 8.0 s (T60), and 30.4 +/- 12.4 s (T90); a significant difference compared to T0 was observed from T15 onward. From T15 onward, tau(2) were not significantly different from values obtained (29.2 +/- 5.3 s) from a group of healthy untrained young controls ( n=7, 21.6 +/- 0.5 years). The same pattern of change as a function of training was described for the VO(2) off-kinetics. It is concluded that in 50-year-old subjects VO(2) on- and off-kinetics are more sensitive to exercise training than other physiological variables determined at peak exercise.

[Relations between pressure overload and early signs of cardiac involvement in arterial hypertension]

In arterial hypertension the indexes of left ventricular hypertrophy are not related to resting blood pressure, whereas a positive association with exercise blood pressure has been observed. It has not been investigated a possible relationship between response to stress and left ventricular diastolic function, the latter being early involved in arterial hypertension even before the development of ventricular hypertrophy. The present study was aimed at assessing a possible relationship between blood pressure response to dynamic exercise and index of left ventricular mass, systolic and diastolic function in a group of untreated hypertensives. fourty hypertensives aged 16-56 years were studied, 27 with mild hypertension and 13 with moderate or severe hypertension. The control group consisted of 23 normotensive healthy subjects, aged 14-40 years. All the subjects underwent a maximum-graded bicycle exercise in the supine position and a M-mode echocardiogram under the B-mode drive. Average values of the indexes of ventricular hypertrophy and of systolic function were overlapping in the 3 groups. Significant differences were observed in the indexes of diastolic function; with regard to normatensive controls, hypertensive subjects showed an increase in isovolumic relaxation time and rapid filling time, a decrease of isovolumic and rapid filling rates and a reduction of mitral valve closing and opening velocities.(ABSTRACT TRUNCATED AT 250 WORDS)