Retraction Systems Research Articles

Comparative evaluation of the amount of gingival displacement produced by three different gingival retraction systems: An in vivo study.

Statement of Problem:Tetrahydrozoline has been introduced as new gingival retraction agent but its clinical efficacy with widely used conventional retraction agents has not been tested.Purpose:The study was designed to clinically evaluate efficacy of newer retraction agent tetrahydrozoline with two widely used retraction systems i.e., Expasyl retraction system and medicated retraction cords on basis of amount of gingival retraction.Materials and Methods:30 subjects were selected according to inclusion and exclusion criteria. Maxillary Impressions were made with irreversible hydrocolloid for all subjects. Tray material was used for making the special tray. Latin Block Design was Used in the Study to avoid tissue fatigue. Retraction was done with aluminium chloride; Tetrahydrozoline and Expasyl according to Latin block design. Impressions were poured with die stone. Casts were retrieved and sections were made with die cutter. 3 mm thin slices were obtained. Each slice was used to measure the amount of retraction under stereomicroscope under 20x and images were transferred to image analyser.Results:The amount of gingival retraction obtained by using aluminium chloride as gingival retraction agent was maximum (148238.33 μm2) compared to tetrahydrozoline (140737.87 μm2) and Expasyl (67784.90 μm2).

Effect of gingival retraction cord and retraction paste on gingival tissue in fixed prosthodontics impression

Background & Objectives: Of the various gingival retraction systems available in the market, a cordless paste system is fairly new entrant into this field. This system promises to provide an easier method to obtain optimum retraction with excellent hemorrhage control. The present study was designed to clinically evaluate the efficacy of paste retraction system and medicated retraction cords on the basis of relative easy of working, hemorrhage control and amount of vertical gingival retraction. Methods: 40 subjects were selected requiring full veneer restoration where more than one abutment teeth were to be prepared. After the preparation of the abutment teeth flexible scales were used to measure the sulcus depth before retraction and after retraction. Medicated retraction cord technique was used on one abutment tooth and on the other abutment tooth paste retraction system was employed. Subjectively easy of placement and hemorrhage scores was assessed. Results: The mean time taken for paste retraction technique was 45.13 seconds and for medicated retraction cord technique was 105.4 seconds. In all the subjects paste retraction technique was relatively easier as compared with medicated retraction cord technique. Mean hemorrhage scores using paste retraction technique was 0.05 and using medicated retraction cord technique it was 1.70. Mean vertical gingival retraction using paste retraction technique was .36mm and using medicated retraction cord technique was 0.54mm Conclusion: Within the limitations of this study, paste retraction system requires reduced time for application, is easier to place, and provides excellent hemorrhage control in comparison to medicated retraction cord. However, medicated retraction cord provides increased amount of vertical retraction as compared to paste retraction technique. DOI: http://dx.doi.org/10.3329/updcj.v3i2.17995 Update Dent. Coll. j: 2013; 3 (2): 20-27

A comparative clinical and quantitative evaluation of the efficacy of conventional and recent gingival retraction systems: An in vitro study

Aim: Gingival deflection techniques can be classified as mechanical, mechanochemical, surgical, or any combination. Comparative evaluations of gingival retraction systems are done rarely mainly because there is no consensus on the evaluation criteria. Therefore, this study aimed to evaluate the efficacy of three different gingival retraction systems, i.e., Magic Foam Cord, expasyl paste, and aluminium chloride-impregnated retraction cord. Materials and Methods: Following impressions, obtained casts were measured for gingival sulcus opening width under optical microscope (with imaging system software). The presence of bleeding after removal of material, ease of procedure, and patient's comfort were also evaluated. The data collected were tabulated and subjected to statistical analysis. Results and Conclusion: Evaluation of the clinical efficacy is relatively difficult because of the lack of appropriate measuring tool. In addition, choice of appropriate gingival retraction system is still a dilemma for the operator. Moreover, a particular clinical situation may indicate the specific technique.

Efficacy of two gingival retraction systems on lateral gingival displacement: A prospective clinical study

PurposeGingival management is a substantive procedure in fixed dental prosthesis treatment. Various new retraction cord systems are available and used. This study aimed to compare the efficacy of a new retraction cord (Stay-Put, Coltene Whaledent AG) and a conventional retraction cord (Ultrapak, Ultradent Products Inc., South Jordan, Utah) on lateral gingival displacement in continuation with the treatment protocol of the subjects fixed dental prosthesis for various partial edentulous conditions requiring fixed dental prosthesis. MethodThirty subjects were selected who needed bilateral fixed dental restoration. In selected subjects both gingival retraction cords were placed bilaterally buccolingually by simple randomization method. After removing the cords, impressions were made and undamaged definitive casts were retrieved. The abutment teeth were sectioned buccolingually at the buccal ridge followed by decimal measurement of the width (in millimeter) of the retracted gingival sulcus, under a traveling microscope. ResultsData was analyzed using SPSS version. Paired "t" test was used to compare the difference between the displaced gingival width in two retraction group (p > 0.05). ConclusionAlthough mean gingival retraction in Stay-Put system (0.528 ± 0.12 mm) was higher as compared to that in Ultrapak (0.487 ± 0.10 mm), the difference between the two systems (0.041 ± 0.11) was not significant statistically (p = 0.057).

Clinical Evaluation of Three New Gingival Retraction Systems: A Research Report

The purpose of this study was to evaluate the clinical efficacy of 3 new gingival retraction systems; Stay-put, Magic foam cord and expasyl, on the basis of their relative ease of handling, time taken for placement, hemorrhage control and the amount of gingival retraction. Thirty subjects were selected requiring fixed prosthesis. The 3 gingival retraction systems were used on the prepared abutments randomly. The time taken for placement of each retraction system was recorded. The vertical gingival retraction was measured before and after retraction using flexible measuring strip with 0.5mm grading. The horizontal retraction was measured on polyether impressions made before the retraction and after retraction. Based on the results, magic foam cord retraction system can be considered more effective gingival retraction system among the three retraction systems used in the study.

Minimally Invasive Cervical Spine Foraminotomy and Lateral Mass Screw Placement

This technique article describes accomplishing multilevel posterior cervical decompression and lateral mass screw placement through a tubular retraction system. Multilevel foraminotomy and instrumented fusion using lateral mass screw fixation can be achieved through a minimally invasive technique using specialized retractors and intraoperative fluoroscopic imaging. Minimally invasive surgical techniques have been adapted to the cervical spine with good results. These techniques have the theoretical advantages of reducing morbidity, blood loss, perioperative pain, and length of hospital stay associated with conventional open posterior spinal exposure. Minimally invasive access to the posterior cervical spine was performed with exposure through a paramedian muscle-splitting approach. With the assistance of a specialized tubular retraction system with a deep soft tissue expansion mechanism, multilevel posterior cervical decompression and fusion can be accomplished. Minimized access to perform multilevel posterior cervical foraminotomy and fusion can be safely accomplished with tubular retraction systems. Complications associated with these techniques can include inadequate decompression, improper instrumentation placement, or neurologic injury due to poor access and visualization. Multilevel foraminotomy and instrumented fusion using lateral mass screw fixation can be safely achieved using these techniques. Complications associated with these strategies are typically due to inadequate visualization, incomplete decompression, or poor placement of instrumentation. As with all minimally invasive spine techniques, the surgeon must ensure that goals of the surgery, both technical and clinical outcomes, are comparable to those of a conventional open procedure.

Primary Closure of Inadvertent Durotomies Utilizing the U-Clip in Minimally Invasive Spinal Surgery

Retrospective clinical cohort study. To examine performance of the U-Clip for the closure of inadvertent durotomy occurring during minimally invasive spinal surgery. Primary closure of inadvertent durotomies that occur during minimally invasive spinal surgery can be technically difficult to accomplish when using standard knot-tying and suture management techniques, owing to the narrow and deep surgical corridor afforded by tubular retraction systems. The U-Clip is a novel device that can achieve tight tissue approximation without the need for knot-tying and excessive suture manipulation, making it ideally suited for use in minimally invasive spinal surgeries. We performed a retrospective review of patients who underwent minimally invasive decompressive procedures complicated by durotomy and repaired using U-Clips for the period January 2008 to January 2010. A total of seven patients were identified. Four of the seven patients were male. Six patients underwent lumbar laminectomy or discectomy. One patient underwent resection of a cervical synovial cyst. In each patient, the durotomy was repaired primarily using U-Clips. All six lumbar patients were discharged home on the same day, and the remaining patient was discharged the following morning. Mean follow-up was 6.3 months. No patient experienced symptoms related to persistent cerebrospinal fluid leakage. Primary closure of an inadvertent durotomy occurring during minimally invasive spinal surgery can be effectively achieved using the self-closing U-Clip device.

Anterior epiduroscopic neural decompression: Eight-center experience in 154 patients

In recent years, technical advances have allowed more significant structural spine surgery through small access portals. Minimally invasive spinal surgery (MISS) is commonly thought of as posterior approaches using muscle dilating tubular retraction systems, but these approaches are best suited to a single spinal level and require bony disruption at each level treated. Access through the sacral hiatus with a flexible endoscope allows an alternative, longitudinal approach to the entire lumbar epidural space. Surgical instruments can be introduced through the endoscope, including laser waveguide fibers. In this article, we expand upon previous reports and describe the combined clinical results of endoscopic laser decompression in 154 patients from 8 centers. All cases of anterior endoscopic neural decompression via sacral laminotomy between December 2009 and May 2011 were reviewed at participating centers and sent a follow-up questionnaire. One hundred and fifty-four cases were identified. There was a significant improvement in disability caused by low-back and/or leg pain as measured by the RMQ. The postoperative level of pain improved from 7.5 to 3.4. By the MacNab scale, success was achieved in 82%. Overall, the patients demonstrated significant clinical recovery and improvement in both quality of life and overall pain levels.

Minimally Invasive Techniques for the Posterior Cervical Spine: Foraminal Decompression and Instrumented Fusion

Minimally invasive surgical techniques have been adopted to treat conditions in the posterior cervical spine. Through specialized tubular retraction systems and proper technique, multilevel posterior cervical foraminal decompression and instrumented fusion can be accomplished though a single incision. In this report we describe the techniques to perform both cervical foraminotomy and lateral mass fixation at 3 or more levels through an expanding tubular retractor. Complications may include inadequate decompression, poor placement of instrumentation, neurologic injury, or iatrogenic postoperative instability. Preoperative planning and careful technique can help avoid specific complications related to tubular access and poor visualization. The surgeon must always be prepared to convert to a traditional open procedure if an adequate decompression and/or fusion cannot be performed because of difficulties related to visualization, distorted anatomy, or improper access.

VarioLift retraction system for laparoscopy without pneumoperitoneum

SummaryThere are adverse effects due to the pneumoperitoneum during laparoscopic surgery, therefore the question of alternative procedures for retracting the abdominal wall has increasingly been discussed. So far, various systems which mechanically retract the abdominal wall have been introduced. However, due to their complicated design or limited visibility, they have not become popular. The modular retraction system (VarioLift, AESCULAP) consists of two components — a retractor for lifting the anterior abdominal wall and a hold-down device for compressing bulging internal organs. Both parts of the abdominal wall retractor are inserted in sequence through a 1.5 cm minilaparotomy and are, after being connected to each other, fixed to a mechanical lifting arm. The parts are available in various sizes and shapes, so that the retractor can be adapted to the respective abdominal quadrant and the anatomic situation of the patient. After lifting the anterior abdominal wall, the hold-down device is inserted, unfolded and positioned to hold down bulging internal organs.In contrast to other retraction systems, the VarioLift system allows the anterior abdominal wall to be raised in a dome-shaped fashion, offering good lateral visibility. The construction of the system, including the minilaparotomy, does not take any longer than the installation of a pneumoperitoneum.

Systems and instruments for laparoscopic surgery without pneumoperitoneum.

The insufflation of carbon dioxide into the peritoneal cavity is a routine technique of abdominal exposure in laparoscopic surgery. Because of adverse physiological effects and technical disadvantages of the pneumoperitoneum, alternative methods of abdominal wall lifting have been explored recently. Two groups of retraction systems exist: intraabdominal lifting and subcutaneous lifting of the abdominal wall. Some systems require additional pneumoperitoneum, because the extent of intraabdominal exposure is not sufficient. Other systems are working completely without gas insufflation. Two systems combine abdominal wall lifting with pressure on the internal organs. Every method allows the use of standard laparoscopic instruments, which originally were designed for a regular pneumoperitoneum. The use of a low-pressure pneumoperitoneum in combination with mechanical augmentation of the peritoneal cavity reduces physiological disadvantages of laparoscopy. But technical advantages, such as combination of laparoscopic and open techniques, can be realized only without gas insufflation. Conventional instruments have been designed to fit the ergonomical needs of isopneumic laparoscopy and to be employed with simple valveless cannulae.

Apneumic laparoscopy in surgical oncology.

Minimally invasive techniques now play an important role in virtually every aspect of general surgery. While it is unlikely that celiotomy for malignant disease will fall into obscurity as rapidly as open cholecystectomy, greater use of videoscopic techniques in surgical oncology are inevitable and will undoubtably improve patient care. Techniques of isopneumic laparoscopy have already proven useful in trauma, cholecystectomy, bowel resection, herniorrhaphy, and a variety of other procedures. Further advances in this technique are dependent on the development of "user friendly" abdominal wall retraction systems.

On the use of vertical loops in retraction systems

W h i l e the final.goal of a retraction system is efficient, effective closure of space within the dental arch, the designs and materials of the appliances used to accomplish this effect vary considerably. Several systems use arch wires for control and elastomers for force application, to allow the canine and other teeth to be guided by this wire during movement (Fig. 1, a). A somewhat different approach uses a metallic loop or spring as the only connection between tooth segments or individual teeth (Fig. 1, b). As shown in Fig. 1, c, when this type of appliance is activated and anchored at each end, it applies forces and moments (couples) to the teeth that are equal and opposite to those necessary to maintain the appliance in its deformed state (Fig. 1, d). Effective repositioning of the teeth with this technique requires that the appliance provide a specific force system (force and moment) to segments or individual teeth in the dental arch. To provide this force system, the appliance must have the following mechanical characteristics: 1. It must provide appropriate levels of force and moment-to-force (M/F) ratios to achieve the tooth displacement desired. 2. It must be able to undergo a reasonable range of activation/deactivation in which the appliance delivers relatively constant forces and moments. 3. It must be small enough to fit comfortably in the space available for intraoral treatment. The relationship between the appliance force system and the resulting tooth movement has been investigated and described by several authors. ,-3 To understand and predict the type of movement that will occur, we describe the effective resistance of the supporting tissues in terms of a center of resistance. A force applied at

Systemic Effects of Epinephrine-Impregnated Retraction Cord in Fixed Partial Denture Prosthodontics

There still is conflict among practitioners and researchers concerning the systemic effects of epinephrine retraction systems. However, the concentration of epinephrine in our commercially available retraction systems, as reported by Shaw, is cause for concern. Therefore, before using these systems, the dentist must consider the following variables: medical history of the patient, health of the oral cavity (especially the dentogingival unit), type of procedure to be done, amount and length of retraction, and exposure of the vascular bed. After careful attention to the foregoing variables, the retraction system of choice is the 8% racemic epinephrine-impregnated retraction cord. In addition to these variables, a calm and organized manner in the dental operatory can and will reassure the patient of the best of care with the least side effects.