Autotransplantation of impacted teeth: a report of 3 cases and review of the literature.

Transplantation of one's own teeth from one site to another is called dental autotransplantation. Because tooth transplantation allows dentofacial development and maintains alveolar bone volume, it is a viable treatment method, especially in young patients with missing teeth or tooth agenesis. Three cases are presented in which missing or agenetic teeth were replaced by autotransplantation of impacted teeth. This article illustrates the option of using impacted teeth as a viable reservoir for autotransplantation in young patients with missing permanent teeth.

Contact damage to root surfaces of premolars touching miniscrews during orthodontic treatment.

INTRODUCTION: Our aim in this clinical study was to examine premolar root surfaces after intentional contact with miniscrews. METHODS: Ten patients (5 male, 5 female; mean age, 15.8 years; range, 13.5-23.2 years) with 2 maxillary first premolars to be extracted as part of their orthodontic treatment participated in the study. Two miniscrews were placed in each patient, and the first premolar roots were tipped into contact with the miniscrews by using tipping springs with a standardized force. Half of the experimental teeth were kept in contact with the screws for 4 weeks (mild resorption) and the other half for 8 weeks (severe resorption). In 5 patients, the screws were removed, and, in the remaining 5, the springs were removed to allow the roots to move back. The roots were allowed to recover for 4 or 8 weeks before extraction. Two premolars with accidental direct contact were used as controls. All teeth were prepared, coated, and examined with scanning electron microscopy. RESULTS: In the control group, the periodontal ligament was removed and the dentin surface denuded. The experimental groups showed signs of resorption with structural surface irregularities. However, no apparent denuded dentin surfaces were seen. Although some resorption lacunae were still discernible at 8 weeks, the collagen fibers fully covered the affected areas. The immature fiber organization in the deepest crater represented the ongoing process of fiber reorganization, compared with the fully matured surface areas surrounding the crater. CONCLUSIONS: The results indicate that root surfaces that touch miniscrews show swift repair and almost complete healing within a few weeks after removal of the screw or the orthodontic force. These findings are based on 10 patients only; verification in a larger study sample is needed.

Accelerated aging effects on surface hardness and roughness of lingual retainer adhesives.

OBJECTIVE: To test the null hypothesis that accelerated aging has no effect on the surface microhardness and roughness of two light-cured lingual retainer adhesives. MATERIALS AND METHODS: Ten samples of light-cured materials, Transbond Lingual Retainer (3M Unitek) and Light Cure Retainer (Reliance) were cured with a halogen light for 40 seconds. Vickers hardness and surface roughness were measured before and after accelerated aging of 300 hours in a weathering tester. Differences between mean values were analyzed for statistical significance using a t-test. The level of statistical significance was set at P < .05. RESULTS: The mean Vickers hardness of Transbond Lingual Retainer was 62.8 +/- 3.5 and 79.6 +/- 4.9 before and after aging, respectively. The mean Vickers hardness of Light Cure Retainer was 40.3 +/- 2.6 and 58.3 +/- 4.3 before and after aging, respectively. Differences in both groups were statistically significant (P < .001). Following aging, mean surface roughness was changed from 0.039 microm to 0.121 microm and from 0.021 microm to 0.031 microm for Transbond Lingual Retainer and Light Cure Retainer, respectively. The roughening of Transbond Lingual Retainer with aging was statistically significant (P < .05), while the change in the surface roughness of Light Cure Retainer was not (P > .05). CONCLUSIONS: Accelerated aging significantly increased the surface microhardness of both light-cured retainer adhesives tested. It also significantly increased the surface roughness of the Transbond Lingual Retainer.

Orthodontic bonding to several ceramic surfaces: are there acceptable alternatives to conventional methods?

INTRODUCTION: The objectives of this study were to determine the effects of various surface conditioning methods on 3 types of ceramic materials (feldsphatic, leucite-based, and lithia disilicate-based) in orthodontic bonding. METHODS: A total of 210 ceramic disk samples were fabricated and divided into 3 groups. In each group, 5 subgroups were prepared by sandblasting; sandblasting and hydrofluoric (HF) acid; sandblasting and silane; sandblasting, HF acid, and silane; and tribochemical silica coating and silane. Mandibular incisor brackets were bonded with light-cured adhesive. The samples were stored in water for 24 hours at 37 degrees C and then thermocycled. Shear bond tests were performed, and the failure types were classified with adhesive remnant index scores. RESULTS: In all 3 ceramic groups, the lowest shear bond strength values were found in the sandblasted-only samples. For the feldspathic and lithia disilicate-based ceramic, the highest bond strength values were obtained with silica coating (15.2 and 13.2 MPa, respectively). For the leucite-based ceramic, HF without silane produced the highest bond strength value (14.7 MPa), but comparable values were obtained with silicatization also (13.4 MPa). CONCLUSIONS: The silica-coating technique could replace the other conditioning techniques in bonding brackets to ceramic. However, debonding must be done carefully because of the risk of porcelain fracture.

Comparison of 2 distalization systems supported by intraosseous screws.

INTRODUCTION: The aim of this study was to compare the effects of 2 distalization systems supported by intraosseous screws for maxillary molar distalization. METHODS: Forty subjects with skeletal Class I dental Class II malocclusion were divided into group 1 (8 girls, 12 boys) and group 2 (11 girls, 9 boys). An anchorage unit was prepared by placing an intraosseous screw in the premaxillary area of each subject. To increase the anchorage in group 2, we used an acrylic plate resembling the Nance button around the screw. The screws were placed and immediately loaded to distalize the maxillary first molars or second molars when they were present. Skeletal and dental changes were measured on cephalograms, and dental casts were obtained before and after distalization. RESULTS: The average distalization times were 4.6 months for group 1 and 5.4 months for group 2. On the cephalograms, the maxillary first molars were tipped 9.05 degrees in group 1 and 0.75 degrees in group 2. The mean distal movements were 3.95 mm in group 1 and 3.88 mm in group 2. On the dental casts, the mean distalization amounts were 4.85 mm for group 1 and 3.70 mm for group 2. In group 1, the maxillary molars were rotated distopalatally to a moderate degree, but this was not significant in group 2. Mild protrusion of the maxillary central incisors was also recorded for group 1 but not for group 2. However, there were no changes in overjet, overbite, and mandibular plane angle measurements for either group. CONCLUSIONS: Immediately loaded intraosseous screw-supported anchorage units were successful for molar distalization in both groups. In group 2, side effects such as molar tipping and rotation were smaller, but distalization times were longer and hygiene was poorer.

Use of the intraosseous screw for unilateral upper molar distalization and found well balanced occlusion.

BACKGROUND: The aim of this study was to present a temporary anchorage device with intraosseous screw for unilateral molar distalization to make a space for the impacted premolar and to found well balanced occlusion in a case. CASE PRESENTATION: A 13-year-old male who have an impacted premolar is presented with skeletal Class I and dental Class 2 relationship. The screw was placed and immediately loaded to distalize the left upper first and second molar. The average distalization time to achieve an overcorrected Class I molar relationship was 3.6 months. There was no change in overjet, overbite, or mandibular plane angle measurements. Mild protrusion (0.5 mm) of the upper left central incisor was also recorded. CONCLUSION: Immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient unilateral molar distalization without anchorage loss. This treatment procedure was an alternative treatment to the extraction therapy.

Temperature rise during orthodontic bonding with various light-curing units--an in vitro study.

The purpose of this in vitro study was to investigate the temperature changes in the pulp chamber during bracket bonding using three different light sources. Bracket bonding was performed on one lower first premolar and one lower central incisor at two different distances (surface and 10 mm). The measurements were taken with a J-type thermocouple wire, placed in the pulp chamber and connected to a data logger. Analysis of variance revealed that pulp chamber temperature changes were influenced by the light source, the tooth type, and the distance from the tip of the light guide to the bracket surface. Halogen induced significantly higher intrapulpal temperature changes than light-emitting diode and Xenon Plasma Arc (PAC) (P = .000). The temperature increase was significantly higher when the light-guide tip was positioned at the surface of the teeth than at the 10-mm distance with all light-curing units (P = .000). All light-curing units produced higher intrapulpal temperature increase in the mandibular incisor than in the premolar. Power PAC produced significantly higher heat changes in the incisor than in the premolar. Orthodontic bonding with different light-curing units did not exceed the critical 5.5 degrees C value for pulpal health.

Degree of conversion of two lingual retainer adhesives cured with different light sources.

The aim of this study was to evaluate the degree of conversion (DC) of two lingual retainer adhesives, Transbond Lingual Retainer (TLR) and Light Cure Retainer (LCR), cured with a fast halogen light, a plasma arc light and a light-emitting diode (LED) at various curing times. A conventional halogen light served as the control. One hundred adhesive samples (five per group) were cured for 5, 10 or 15 seconds with an Optilux 501 (fast halogen light), for 3, 6 or 9 seconds with a Power Pac (plasma arc light), or for 10, 20 or 40 seconds with an Elipar Freelight (LED). Samples cured for 40 seconds with the conventional halogen lamp were used as the controls. Absorbance peaks were recorded using Fourier transform infrared (FT-IR) spectroscopy. DC values were calculated. Data were analysed using Kruskal-Wallis and Mann-Whitney U-tests. For the TLR, the highest DC values were achieved in 6 and 9 seconds with the plasma arc light. Curing with the fast halogen light for 15 seconds and with the LED for 40 seconds produced statistically similar DC values, but these were lower than those with the plasma arc light. All of these light exposures yielded a statistically significantly higher DC than 40 seconds of conventional halogen light curing. The highest DC value for the LCR was achieved in 15 seconds with the fast halogen light, then the plasma arc light curing for 6 seconds. These two combinations produced a statistically significantly higher DC when compared with the 40 seconds of conventional halogen light curing. The lowest DC for the LCR was achieved with 10 seconds of LED curing. The overall DC of the LCR was significantly higher than that of the TLR. The results suggest that a similar or higher DC than the control values could be achieved in 6-9 seconds by plasma arc curing, in 10-15 seconds by fast halogen curing or in 20 seconds by LED curing.

Comparison of two different gingivectomy techniques for gingival cleft treatment.

Interdental clefts or invaginations contribute to orthodontic relapse and poor periodontal health in extraction cases. These clefts or invaginations can be removed both by electrosurgical or conventional surgical gingivectomy techniques. This study investigates and compares the efficacy of two different techniques to remove gingival clefts with respect to periodontal health and patient tolerance. Twenty-two patients (mean age, 15.7 years) with bilateral gingival clefts participated in this study. In each patient, the gingival invaginations were removed by gingivectomy using electrosurgery on one side and conventional surgery on the contralateral side. The length and depth of the invaginations, the gingival index of the adjacent teeth, and the changes in visual analogue scale scores were recorded before and after the operation for both groups. Mann-Whitney U-test and Wilcoxon tests were used to analyze the data statistically. The results showed significant improvement in invagination depth and length and gingival index scores for both techniques. There were no statistical differences between the two gingivectomy techniques with respect to gingival health and patient tolerance. Both techniques can be used to remove the gingival invaginations efficiently.

In vitro evaluation of shear bond strengths and in vivo analysis of bond survival of indirect-bonding resins.

In this study we evaluate the shear bond strengths (SBS) of indirect-bonding systems available on the market. For the in vitro study, 60 extracted premolars were divided into three groups. In indirect group I, the brackets were bonded to models using Therma Cure laboratory resin and transferred to the teeth using Custom IQ resin for indirect bonding. For indirect group II, the teeth were attached to models using Transbond XT and transferred using Sondhi Rapid Set. In the direct-bonding group, the brackets were bonded to teeth directly using Transbond XT The SBS were evaluated, and the comparisons were made. In the in vivo study, left half of the upper arch and right half of the lower arch were bonded using Sondhi's indirect-bonding resin and right half of the upper arch and left half of the lower arch were bonded using Therma Cure as a laboratory resin and Custom IQ as a clinical bonding resin. The failure rates of the brackets were followed for nine months. Analysis of variance and Tukey tests were performed. Mean SBS values (MPa) were 10.3 +/- 4.2, 6.1 +/- 1.6, and 12.8 +/- 5.4 for the indirect groups I and II and for the direct-bonding group, respectively. There were no significant differences between indirect group I and direct group (P > .05), whereas both yielded significantly higher SBS values compared with indirect group II. In vivo bond survival evaluation showed no differences between the two indirect-bonding systems available.

Effect of light-emitting diode on bond strength of orthodontic brackets.

The aim of this study was to evaluate the effect of light-emitting diode (LED) light curing on shear bond strength (SBS) of orthodontic brackets bonded to teeth. Light exposure of 40 seconds from a conventional halogen-based light-curing unit was used as a control. Eighty human premolars were divided into four groups of 20 each. Brackets were bonded to acid-etched teeth with Transbond XT light-cured adhesive. In the first group, the adhesive was light cured for 40 seconds with a conventional halogen unit (XL3000, 3M). In the other three groups, adhesive was cured with a commercial LED unit (Elipar FreeLight, 3M ESPE) for 10, 20, or 40 seconds. SBS of brackets was measured on a universal testing machine and recorded in megapascals. Adhesive remnant index (ARI) scores were determined after failure of brackets. Data were analyzed using analysis of variance and chi-square tests. No statistically significant differences were found among the SBS values of halogen-based light-cured (13.1 +/- 3.1 MPa) and 20- and 40-second LED-cured (13.9 +/- 4.8 MPa and 12.7 +/- 5.1 MPa) specimens (P > .05). However, 10 seconds of LED curing yielded significantly lower SBS (P < .05). No statistically significant differences were found between the ARI scores among groups. The results of this study are promising for the orthodontic application of LED-curing units, but further compatibility and physical characteristic studies of various orthodontic adhesives and clinical trials should be performed before validation.

Intraosseous screw-supported upper molar distalization.

The aims of the present study were to investigate (1) the efficiency of intraosseous screws for anchorage in maxillary molar distalization and (2) the sagittal and vertical skeletal, dental, and soft tissue changes after maxillary molar distalization using intraosseous screw-supported anchorage. Twenty-five subjects (18 girls and seven boys; 11.3 to 16.5 years of age) with skeletal Class I, dental Class II malocclusion participated in the study. An anchorage unit was prepared for molar distalization by placing an intraosseous screw behind the incisive canal at a safe distance from the midpalatal suture following the palatal anatomy. The screws were placed and immediately loaded to distalize upper first molars or the second molars when they were present. The average distalization time to achieve an overcorrected Class I molar relationship was 4.6 months. The skeletal and dental changes were measured on cephalograms and dental casts obtained before and after the distalization. In the cephalograms, the upper first molars were tipped 8.8 degrees and moved 3.9 mm distally on average. On the dental casts, the mean distalization was five mm. The upper molars were rotated distopalatally. Mild protrusion (mean 0.5 mm) of the upper central incisors was also recorded. However, there was no change in overjet, overbite, or mandibular plane angle measurements. In conclusion, immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient molar distalization without major anchorage loss.

A practical method of fabricating a lingual retainer.

Retention is a major part of orthodontic treatment, not an optional secondary protocol. In recent years, studies investigating dentofacial changes during and after the growth period have led most clinicians to use fixed retention appliances after treatment. Fixed retainers can be attached to the teeth directly or indirectly. We present a practical, indirect method for bonding fixed retainers, using Sondhi Rapid-set Indirect Bonding Adhesive (3M Unitek, Monrovia, Calif).

Effects of fast halogen and plasma arc curing lights on the surface hardness of orthodontic adhesives for lingual retainers.

The aims of this study were to (1) identify the optimum cure times of 2 different lingual retainer adhesives with a conventional halogen, a fast halogen, and a plasma arc light by measuring Vickers surface hardness, and (2) determine whether different lights produce similar surface hardness values for the same adhesive resin material. The investigated plasma arc curing unit was the PowerPac (American Dental Technologies, Corpus Christi, Tex), and the fast halogen unit was the Optilux 501 (Kerr, Orange, Calif). A conventional curing unit, the Ortholux XT (3M Dental Products, St. Paul, Minn) was used as the control. Two orthodontic lingual retainer adhesives were used: Transbond Lingual Retainer (3M Unitek, Monrovia, Calif) and Light Cure Retainer (Reliance Orthodontic Products, Itasca, Ill). Concise (3M Dental Products) and diluted Concise were used as controls. Transbond Lingual Retainer was polymerized by the PowerPac light in 6 seconds, by the Optilux in 10 seconds, and by the conventional halogen light in 20 seconds. The minimum curing times for Light Cure Retainer adhesive were 15 seconds for PowerPac, 10 seconds for Optilux, and 40 seconds for conventional halogen. Surface hardness values for each resin did not differ significantly with different curing units. However, different adhesives demonstrated significantly different surface hardness values. Final Vickers surface hardness values (averaged across curing units) of Transbond Lingual Retainer, Concise, diluted Concise, and Light Cure Retainer were 62.8, 52.4, 46.0, and 40.4, respectively. Plasma arc or fast halogen units polymerize resin composite adhesive in much shorter times than do conventional curing units, without a significant loss in surface hardness. Therefore, these units are suggested for clinical use to save chairside time.

Effect of self-etching primers on bond strength--are they reliable?

Currently introduced self-etching primers combine conditioning and priming agents into a single product. The purpose of this study was to determine the effects of using three self-etching primers on the shear bond strength (SBS) of orthodontic brackets and on the bracket/adhesive failure mode. Brackets were bonded to extracted human teeth according to one of four protocols. In the control group, teeth were etched with 37% phosphoric acid. In the experimental groups, the enamel was conditioned with three different self-etching primers, Clearfil SE Bond (CSE), Etch & Prime 3.0 (EP3), or Transbond Plus (TBP), as suggested by the manufacturer. The brackets were then bonded with Transbond XT in all groups. The present in vitro findings indicate that conditioning with TBP before bonding orthodontic brackets to the enamel surface resulted in a significantly (P < or = .001) higher SBS (mean, 16.0 +/- 4.5 MPa) than that found in CSE, EP3, and the control (acid-etched [AE]) groups. CSE produced bond strength values (mean 11.5 +/- 3.3 MPa) that are statistically comparable to those produced by acid etching (mean 13.1 +/- 3.1 MPa). The use of EP3 for enamel conditioning resulted in the lowest mean SBS value (mean 9.9 +/- 4.0 MPa). A comparison of the adhesive remnant index scores indicated that there was more residual adhesive remaining on the teeth that were treated with conventional acid etching than in the CSE and EP3 groups. In the TBP group, the failure sites were similar to those of the AE group but different from those of the CSE group.