Lingual Retention Research Articles

\u201cClinical comparison of bond failure rate between two types of mandibular canine-canine bonded orthodontic retainers- a randomized clinical trial\u201d

BackgroundBonded retainers are widely used as they are esthetically pleasing, easily acceptable, provide greater stability, compliance free and causes no soft tissue irritation and speech problems. Though, fracture and bond failure are their shortcomings. Therefore, the objectives of this study were to evaluate the number of bond failures and type of failure pattern between two types of mandibular canine-canine bonded retainers.MethodsTotal 60 subjects were recruited initially and were assessed for eligibility, out of which 6 were excluded and 2 were lost to follow up. They were randomly divided into two groups. Fiber reinforced composite (FRC) retainers were inserted in group 1 subjects while group 2 subjects received multistranded stainless steel (MSW) retainers. The subjects were recalled after every 3 months over a period of 1 year. Bond failure rate and failure pattern based on adhesive remnant index were evaluated at each visit. The bond failure rate and failure pattern were compared between the two retainers by using Chi-square test.ResultsThe bond failure rates were 42.94% for FRC retainer and 31.41% for MSW retainer. Hence, total number of bond failures in both retainers were 37.17%. The difference of bond failure between two groups was statistically significant (p = 0.012). Type “0” failure pattern was detected commonly with both types of retainers (p < 0.001).ConclusionOur findings indicate that multistranded stainless steel wire retainer is a superior option to be used for fixed lingual retention in mandibular arch as it exhibited lower bond failure as compared to fiber reinforced composite retainer. Adhesive failure is the most common type of bond failure observed with both types of fixed retainers.Trial registrationID NCT03881813 (https://clinicaltrials.gov/); March 19, 2019, retrospective registration.

Comparison of Shear Bond Strength of Different Wire-Composite Combinations for Lingual Retention: An in Vitro Study

Context: As lingual bonded retainers are required for long-term retention in the oral cavity, the wire-composite combination of choice may be the determining factor for the success of lingual bonded retainers. Aim: We compared the shear bond strength of different wire-composite combinations used for lingual bonded retainers and identified the combination of choice for lingual retention in terms of the shear bond strength. Materials and Methods: A total of 108 extracted human maxillary premolars in pairs were divided into 6 groups of 9 samples each. Three different types of retainer wires (namely, Respond [Ormco Corp., Orange, CA, USA], Leone Ligature Wire [Leone S.p.a., Firenze, Italy], and SRW™ Stranded Retention Wire [Ortho Classic Inc., USA]) were bonded to the teeth with the composites (G-aenial™ Universal Flo and Tetric N-Flow). The shear bond strength was measured on debonding using universal testing machine INSTRON. Results: The maximum shear bond strength (58.28 N) was observed in group IV (Respond wire with Tetric N-Flow), whereas the minimum (25.28 N) was observed in group VI (SRW™ Stranded Retention Wire with Tetric N-Flow). A highly significant difference was observed when the shear bond strength of group IV was compared with all the other groups. Conclusions: The maximum shear bond strength was observed in the wire-composite combination of Respond dead-soft wire with Tetric N-Flow composite. Therefore, it could be the wire-composite combination of choice for bonded lingual retainer.

Retainer Clip - Stabilizer for Lingual Retainer

Retention is the most important factor after the orthodontic treatment of the malocclusions. Most of the cases require fixed lingual retention. This article describes an easy method to stabilize lingual retainer and to adjust to its final position before bonding.

Assessing the feasibility of yttria-stabilized zirconia in novel designs as mandibular anterior fixed lingual retention after orthodontic treatment.

The purpose of this study is to explore the feasibility of yttria-stabilized zirconia (Y-TZP) in fixed lingual retention as an alternative to stainless steel. Exploratory Y-TZP specimens were milled to establish design parameters. Next, the specimens were milled according to ASTM standard C1161-13 and subjected to 4-point flexural tests to determine material properties. Finite elementanalysis was used to evaluate 9 novel cross-sectional designs, which were compared with stainless steel wire. Each design was analyzed under loading conditions to determine von Mises and bond stresses. The most promising design was fabricated to assess the accuracy and precision of current CAD/CAM milling technology. The superior design had a 1.0×0.5mm semielliptical cross-section and was shown to be fabricated reliably. Overall, the milling indicated a maximum percent standard deviation of 9.3 and maximum percent error of 13.5 with a cost of $30 per specimen. Y-TZP can be reliably milled to dimensions comparable with currently available metallic retainer wires. Further research is necessary to determine the success of the bonding protocol and the clinical longevity of Y-TZP fixed retainers. Advanced technology is necessary to connect the intraoral scan to an esthetic and patient-specific Y-TZP fixed retainer.

Stabilising Springs for Fixed Lingual Retainer

Most treated malocclusion needs fixed lingual retention. To stabilise fixed lingual retainer in the exact location needs proper stabilisation. Proper stabilization requires a holding spring. This Stabilising Spring should be easy to fabricate and help the clinician to stabilise the retainer quickly and save the chair side time. More over it should not irritate the mucosa and should be easy to insert and remove.

Piezography: An Innovative Technique in Complete Denture Fabrication

ABSTRACTIncreasing life expectancy, age-related reduction in adaptability and progressive severe mandibular resorption, all add to the difficulty in achieving prosthetic success. The conventional mandibular denture is usually less retentive than the maxillary one and successful treatment involves the development of lingual retention for the mandibular denture. Several methods taking into account physiologic function with an objective to enhance denture retention and comfort during mastication have been developed since many decades. The present article describes piezography as a method to enhance retention, stability and function for the mandibular denture through a case report.How to cite this articleBhattacharyya J, Goel P, Ghosh S, Das S. Piezography: An Innovative Technique in Complete Denture Fabrication. J Contemp Dent 2012;2(3):109-113.

The use of a neodymium-iron-boron magnet device for positioning a multi-stranded wire retainer in lingual retention--a pilot study in humans

The aim of this study was to evaluate the time requirement of a newly developed device made of neodymium-iron-boron (NdFeB) magnets for positioning a multi-stranded, canine-to-canine retainer during bonding compared with dental floss and a transfer tray. Forty-five patients aged between 12 and 33 years (26 male, 19 female) previously treated with fixed appliances were enrolled in the study. The patients were randomly allocated to three groups (15 per group). For each group a mandibular canine-to-canine retainer of 0.018 inch Dentaflex multi-stranded wire (Dentaurum) was prefabricated for each patient on a cast. The bonding procedure was identical, except for the method of positioning the wire during adhesive fixation: group A dental floss, group B a small prefabricated transfer tray of dental resin and group C the NdFeB magnet device. For each group, the time required for the complete bonding process was measured. Kruskal-Wallis and Wilcoxon-Mann-Whitney tests were used for group and pairwise comparisons, respectively. The three methods required statistically significant different times (P < 0.001). The Wilcoxon-Mann-Whitney test revealed that wire positioning with the magnet device was significantly faster [4.98 minutes; standard deviation (SD) 0.68 minutes] than with dental floss (7.65 minutes, SD 1.14 minutes; P = 0.0001) or with transfer tray (5.75 minutes, SD 0.57 minutes; P = 0.001). The NdFeB magnet device is a timesaving appliance for positioning a multi-stranded, canine-to-canine retainer during bonding when compared with dental floss and an individually prefabricated transfer tray.

Lingual Retention and the Elimination of the Visible Clasp Arm

The modern removable partial denture (RPD), in response to the increased esthetic demands of our patients, is no longer acceptable if it requires visible buccal and facial clasp arms for retention. By eliminating the bracing arm and having its functions taken by paralleled guide planes and precise, positive rests, the retentive element, a lingual circumferential wire clasp arm, will provide the same amount of retentive force as if it were placed on the buccal surface and will not be visible. Designs for the major connector either plate the lingual surface of the abutment or, as in a lingual bar, leave that surface open. Both of these situations are adaptable to the lingual retentive clasp and are illustrated in this article. Design features such as metal clasps needed for the retention of RPDs can be very unsightly, creating an esthetic problem. This article reviews the concepts for creating lingual clasp arms that enhance the esthetic quality of prostheses.

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Time-saving fixed lingual retainer using DuraLay resin transfer

There is general agreement on the necessity of fixed lingual retainers to prevent relapse in many patients after active orthodontic treatment. 1 Bearn D.R. Bonded orthodontic retainers a review. Am J Orthod Dentofacial Orthop. 1995; 108: 207-213 Abstract Full Text Full Text PDF PubMed Scopus (114) Google Scholar , 2 Cerny R. Permanent fixed lingual retention. J Clin Orthod. 2001; 35: 728-732 PubMed Google Scholar , 3 Durbin D.D. Relapse and the need for permanent fixed retention. J Clin Orthod. 2001; 35: 723-727 PubMed Google Scholar Several methods for delivering fixed lingual retainers have been introduced. 2 Cerny R. Permanent fixed lingual retention. J Clin Orthod. 2001; 35: 728-732 PubMed Google Scholar , 4 Corti A.F. Technique clinic an indirect-bonded lingual retainer. J Clin Orthod. 1991; 25: 631-632 PubMed Google Scholar , 5 Haydar B. Haydar S. An indirect method for bonding lingual retainers. J Clin Orthod. 2001; 35: 608-610 PubMed Google Scholar , 6 Becker A. Goultshin J. The multistranded retainer and splint. Am J Orthod. 1984; 85: 470-474 Abstract Full Text PDF PubMed Scopus (17) Google Scholar , 7 Bantleon H.P. Droschl H. A precise and time-saving method of setting up an indirectly bonded retainer. Am J Orthod Dentofacial Orthop. 1988; 93: 78-82 Abstract Full Text PDF PubMed Scopus (4) Google Scholar , 8 Liou E.J.W. Chen L.I.J. Huang C.S. Nickel-titanium mandibular bonded lingual 3-3 retainer for permanent retention and solving relapse of mandibular anterior crowding. Am J Orthod Dentofacial Orthop. 2001; 119: 443-449 Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar , 9 Karaman A.I. Kir N. Belli S. Four applications of reinforced polyethylene fiber material in orthodontic practice. Am J Orthod Dentofacial Orthop. 2002; 121: 650-654 Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar However, bonding a lingual retainer is still challenging because it requires long working time and has a risk of contamination from saliva and moisture, which can cause bonding failure. In addition, it is difficult to adapt the retainer wire to perfectly fit the lingual surfaces of an anterior tooth. We developed a method of fabricating a fixed lingual retainer using DuraLay resin (Reliance Dental Manufacturing, Worth, Ill) and have used this method with satisfactory results for nearly 10 years on thousands of patients. This technique has proven to be a reliable, convenient, and time-saving procedure.

Effects of preparation designs and adhesive systems on retention of class II amalgam restorations

Purpose. This study evaluated the effects of three preparation designs and the influence of an adhesive system in Class II amalgam restorations when a load was applied directly to the marginal ridge. Material and methods. Seventy-two sound caries-free maxillary molars were divided into 6 groups of 12 teeth. In groups 1 and 4, the preparation had an extension through the occlusal groove, whereas the other four groups used a proximal slot (box-only) preparation. Groups 2 and 5 had facial and lingual retention grooves that extended from the gingival floor to the occlusal surface, and groups 3 and 6 had slots without grooves. Teeth in groups 1, 2, and 3 were restored with amalgam and groups 4, 5, and 6 were restored with resin bonded amalgam. The marginal ridges of the restorations were loaded at an angle of 13.5 degrees to the long axis of the tooth in an Instron testing machine until failure. Results. Analysis of mean failure loads indicated that proximal slot preparations with retention grooves or occlusal extensions were statistically equivalent but significantly greater than proximal slots without grooves. The addition of an adhesive system improved fracture values for all three types of preparations. Conclusions. When proximal caries was diagnosed and no occlusal caries was evident, a proximal slot amalgam restoration combined with retention grooves and an adhesive system was the appropriate choice. (J Prosthet Dent 1997;78:250-4.)

Gravity-induced stresses by an obturator prosthesis

Recontruction after surgical resection of tumors of the maxillae and paranasal sinuses is difficult. In addition to the intermittent forces encountered during function, the prosthesis is subjected to the constant force of gravity. This investigation photoelastically studies the gravity-induced stresses transmitted to the remaining oral structures by various obturator prosthesis framework designs. Frameworks which used I-bar and circumferential retainers with buccal retention were most kind to remaining structures. These same designs with lingual retention were most severe, while the swinglock and light wire retainers were intermediate in generated stress.

Occlusal force transfer by removable partial denture designs for a radical maxillectomy

Several removable partial denture retainers were tested on a photoelastic cast of a human maxilla that had undergone a surgical resection through the midline. The conclusions based on the results of these tests are as follows. Physiologic adjustment of all the designs tested revealed a dramatic reduction in stresses when the framework were placed into position. Under load, the physiologically adjusted frameworks produced less potentially damaging stresses in the supporting structures than the unadjusted frameworks. High stresses were located at the premolar region for all the designs. Lingual retainers produced higher stress concentration than buccal retainers. In the anterior region, the I-bar retainer with a cingulum rest was the best combination for transmitting the occlusal forces along the long axis of the tooth. From the perspective of the equitability of stress transfer, the tested designs from best to worse are infrabulge I-bar retainer, either buccal or lingual retention; light wire circumferential retainer with buccal retention; and the circumferential cast buccal retention, swing-lock system.

Framework retention for maxillary obturator prostheses

An in vitro study was done to evaluate the relative effectiveness of clasp placement in specific obturator framework designs. Three commonly encountered defects were studied. These included (1) the antero-hemimaxillectomy, in which the only remaining dental support is from canine to second molar on one side; (2) the hemimaxillectomy, in which the defect extends the length of the midpalate to the mesial surface of the central incisor; and (3) the partial or posterior maxillectomy, in which all six anterior teeth remain along with all posterior teeth on the nondefect side. Three frameworks that demonstrated the following design characteristics were made for each cast: (1) full lingual plate with buccal retentive arms, (2) lingual retention with buccal reciprocation, and (3) buccal and lingual retention.

Retention of obturator-removable partial dentures: A comparison of buccal and lingual retention

An in vitro study was performed to measure the influence of a simulated obturator on the amount of force required to dislodge a simulated unilateral removable partial denture with various clasp designs. The presence of an obturator reduces the retentive capability of a removable partial denture. Lingual retention appeared to provide more resistance to displacement than buccal retention. Infrabulge clasp designs appeared to be more retentive than suprabulge clasp designs.