A Prospective Randomized Study of Different Retainer Types

BACKGROUND AND AIM: In recent years, fixed lingual retainers have been gaining importance in relapse prevention. The aim of this prospective, randomized study was to compare different types of fixed retainers used for stabilization of the lower anterior segment with respect to detachment rate, relapse, periodontal and oral hygiene problems, as well as subjective patient discomfort. PATIENTS AND METHOD: Two types of fixed, customized canine-to-canine retainers (attached to six teeth) with wire diameters of 0.0215" and 0.0195" as well as one type of prefabricated canine-and-canine retainer (bonded to two teeth) were investigated in a total of 103 patients. Some retainers were inserted under dry field conditions using a rubber dam, and the others under relatively dry conditions using cotton rolls. In addition, two types of composite, Heliosit and Concise, were compared. RESULTS: The canine-and-canine retainer displayed an 18% detachment rate, a value significantly lower than the 29% determined for the 0.0195" canine-to-canine retainers. The 0.0215" canine-to-canine retainer had the highest detachment rate (53%). The 37% detachment rate with dry field bonding was slightly higher than the 32% with relatively dry field bonding. Comparison of the composites showed a significantly higher detachment rate for Heliosit (73%) than for Concise (27%). Plaque accumulation increased with all retainer types in the course of the study, but with no significant inter-group differences. Tooth position with canine-to-canine retainers showed a good degree of stability. The canine-and-canine retainer induced frequent relapse of incisors not bonded to the retainer. In view of their higher rate of subjective discomfort, canine-and-canine retainers were given a significantly poorer rating than their canine-to-canine counterparts.     

A modified Thermoplastic Retainer

The aim of this article is to describe a method for fabricating a new esthetic maxillary retainer. To fabricate this retainer it is necessary to fit a segment of orthodontic wire in the maxillary molar and premolar region, followed by plasticization of the model. In order to allow occlusal finishing the occlusal and incisal surfaces of the plate are removed. The described retainer can be a useful alternative to the orthodontist for esthetic orthodontic retention.     

Buffered Lidocaine for Incision and Drainage: A Prospective,Randomized Double-blind Study

IntroductionBuffered local anesthetics have not been studied for incision and drainage procedures in dentistry. The purpose of this prospective, randomized, double-blind study was to compare the pain of infiltration and pain of an incision and drainage procedure by using a buffered versus a nonbuffered 2% lidocaine with 1:100,000 epinephrine solution in symptomatic patients with a diagnosis of pulpal necrosis and associated acute swelling.MethodsEighty-one adult patients were randomly divided into 2 treatment groups who received 2 infiltrations (mesial and distal to the swelling of the same formulation) by using either 2% lidocaine with 1:100,000 epinephrine buffered with 0.18 mL 8.4% sodium bicarbonate or 2% lidocaine with 1:100,000 epinephrine. Patients rated pain of needle insertion, placement, and solution deposition for each infiltration on a 170-mm visual analog scale. An incision and drainage procedure was performed, and the pain of incision, drainage, and dissection was recorded.ResultsNo significant differences were found between the 2 anesthetic formulations for pain of solution deposition for either the mesial or distal site infiltrations. Moderate-to-severe pain was experienced in the majority of patients with the incision and drainage procedure. No significant differences were found between the 2 formulations.ConclusionsThe addition of a sodium bicarbonate buffer to 2% lidocaine with 1:100,000 epinephrine did not result in significantly decreased pain of infiltrations or significantly decreased pain of the incision and drainage procedure when compared with 2% lidocaine with 1:100,000 epinephrine in symptomatic patients with a diagnosis of pulpal necrosis and associated acute swelling.     

An All Porcelain Lingual Bonded Retainer: A Case Study

In recent years, resin bonded metal retainers have been used to replace teeth in a conservative manner. In addition, porcelain laminates or veneers have been used in esthetic dentistry on single teeth in areas that previously dictated reductions of tooth structure. This paper describes a method of replacing a missing lower anterior tooth with an all porcelain bonded retainer.     

A Comparative Micro-topographic Study of the Buccal Enamel of Different Tooth Types

Abstract

The aim of this study was to perform an in vitro examination of the etch pattern achieved on the orthodontic bonding area (OBA) of different tooth types, and to compare the extent and definition of etch achieved. Six examples of each permanent human tooth type were studied. These were collected from adolescents. A standardized etch regime was employed on the OBA and the etch pattern examined under the scanning electron microscope. The degree of definition of etch achieved on every third enamel prism was evaluated. Results showed that the extent of etch achieved decreased toward the distal end of each arch and was significantly less on the first molars (covering <2% OBA) than on the incisors (covering >90% OBA). It was also noted that the degree of definition became poorer towards the distal end of the arches and was worst on the mandibular molars.

It is suggested that the etched enamel morphology of different tooth types could affect composite resin bond strengths. Consequently, this feature could effect the clinical survival of orthodontic brackets and contribute to the higher failure rate of brackets on posterior teeth.     

Evaluation of Two Different Methods of Arch Bar Application: A Comparative Prospective Study

Purpose

To comparatively evaluate the efficacy of a pencil type wire twister and the normal wire twister in terms of various parameters during arch bars application.

Method

The study involved residents of the department enrolled in MDS course. Two study groups of 60 patients each were made by randomly selecting the patients from the outpatient department of Oral and Maxillofacial surgery who required arch bar application. Group A included the patients who underwent upper and lower arch bar application with the use of a pencil type twister and group B included patients who underwent arch bar application with a normal wire twister. All respondents were given a questionnaire after the completion of procedure involving the use of medical sharps. The paired samples t test was used for statistical analysis.

Result

Among group A, mean glove perforations, actual wire stick injuries, mean time taken to complete the procedure, mean wire breakage during the procedure was less than in group B. Comfort level of patients and Ease of operator while performing the procedure was more in group A than in group B. Frictional abrasion of the finger was not associated with the use of pencil type twister. Overall rating of the procedure was more in group A than group B.

Conclusion

The use of pencil type wire twister outweighs normal wire twister in various ways. It increases the overall efficacy of the operator during the procedure.     

Hawley保持器和压膜式保持器患者接受度的问卷调查分析

目的：比较患者对Hawley保持器和压膜式保持器的接受程度,为临床选择合适的正畸保持器类型提供参考。方法：选择固定矫治刚结束的正畸患者24例,分别戴用压膜式保持器和Hawley保持器各2周,问卷调查两种保持器的接受程度,使用SAS软件作符号秩和检验（Signed rank sumtest）和Fisher’s确切检验（Fisher’s Exacttest）,比较两组间差异。结果：患者每周/每天戴用两种保持器的时间无显著差异;压膜式保持器对发音的影响和异物感明显小于Hawley保持器（P〈0.05）,但患者对两种保持器的美观评价无明显差异。结论：压膜式保持器较Hawley保持器更易获得患者的接受,但使用压膜式保持器并不能增加患者戴用保持器的依从性,提示两种保持器均需要患者积极配合以保证足够的保持时间。     

A Prospective Randomized Clinical Trial to Compare Pre-coated and Non-pre-coated Brackets

Abstract

Objective: To compare the clinical failure rate of pre-coated brackets and brackets bonded using Transbond XT light cure system

Outcome measures: (i) The clinical time required for bond up of upper and lower arches of both systems, (ii) bond failure rate for the first 6 months.

Design: Single centre randomized controlled clinical study. Thirty-three patients were bonded using a split mouth technique: randomly allocating the pre-coated brackets to upper left and lower right quadrants, and non-pre-coated brackets to the other quadrants.

Setting: Hospital Orthodontic Department, Basingstoke, Hampshire, UK.

Subjects: Orthodontic patients requiring fixed appliances.

Main outcome measures: The site and time to bond failure was recorded for each bracket that failed over the first 6 months. The time required to bond upper and lower arches was measured using a stopwatch for each patient.

Results: t-Test for the difference of mean time needed to apply both groups of brackets, no significant difference (P > 0.2) was found. A chi-squared test for the difference in bracket failure between pre-coated (8.06%) and non-pre-coated (7.37%) showed no significant difference in bracket failure (P > 0.2).

Conclusions: The clinical failure rate of pre-coated brackets is not significantly lower than conventional non-pre-coated brackets.     

Regenerative Endodontics Versus Apexification in Immature Permanent Teeth with Apical Periodontitis: A Prospective Randomized Controlled Study

Introduction

The aim of the study was to compare the outcomes of regenerative endodontic treatment (RET) and apexification on immature permanent teeth with pulp necrosis and apical periodontitis.

Comparison of Maxillary Lateral Incisor Infiltration Pain Using the Dentapen and a Traditional Syringe: A Prospective Randomized Study

IntroductionThe anterior maxillary infiltration is one of the more painful dental injections. The Dentapen is an electronic syringe that uses computer-controlled delivery technology to administer dental local anesthesia at a slow controlled rate. The purpose of this prospective, randomized, single-blind study was to evaluate solution deposition pain of a maxillary lateral incisor infiltration using the Dentapen with the slow flow rate (1.8 mL/162 sec) and ramp-up setting compared with a traditional syringe infiltration at a flow rate of 1.8 mL/60 sec.MethodsOne hundred thirty adults were administered a maxillary lateral incisor infiltration with the Dentapen and a traditional syringe at 2 separate appointments in a single-blind manner. The infiltrations of 2% lidocaine with 1:100,000 epinephrine were given at a rate of 1.8 mL/162 sec with the ramp-up feature for the Dentapen and 1.8 mL/60 sec for the traditional infiltration. The pain of solution deposition was recorded on a visual analogue scale. At the conclusion of the study, subjects selected their preferred injection technique. The data were analyzed statistically using paired t tests, a mixed-effect model, and odds ratio.ResultsThe pain of solution deposition was significantly less for the Dentapen injection than the traditional injection (P < .001). With the Dentapen device, 16% experienced moderate pain, and for the traditional syringe, 39% experienced moderate pain. Overall, 75% of subjects preferred the Dentapen injection over the traditional injection.ConclusionsThe Dentapen, using the slow flow rate and ramp-up mode, significantly reduced the pain of solution deposition for maxillary lateral incisor infiltrations.     

Anesthetic Efficacy of Supine and Upright Positions for the Inferior Alveolar Nerve Block: A Prospective,Randomized Study

Introduction

It has been recommended to place patients in an upright position after administration of an inferior alveolar nerve block (IANB), theoretically allowing the anesthetic to diffuse in an inferior direction and resulting in better pulpal anesthesia. The purpose of this study was to compare an upright versus a supine position on the success of pulpal anesthesia when an IANB was administered in asymptomatic teeth.

套筒冠固位种植义齿修复牙列缺失

采用CDIC一段式叶状种植体、锥状螺旋种植体植入牙列缺失患者的颌骨内，种植体上部修复结构为套筒冠及桥架连接固位，以覆盖或种植义齿修复3例牙列缺失。本文详细介绍该修复义齿的制作方法，并对种植体的选择、义齿设计特点及支持方式进行报告和讨论。笔者临床观察病例一年，一段式种植体稳固，与骨界面形成骨性结合。提出种植体早期应保持无负荷状态并使用过渡性中空保护性义齿是种植体稳固的重要保证。对套简内、外冠及种植体基桩的适应性及缓冲的要求也是修复体成功的重要条件。该修复方法、材料、工艺较为简单，集活动一固定联合修复的特点。患者对其效果满意。有关该修复体在行使功能中对种植体的应力作用特点及义齿的远期效果将进一步观察。     

Outcome of Regenerative Endodontic Procedures in Nonvital Immature Permanent Teeth Using 2 Intracanal Medications: A Prospective Randomized Clinical Study

IntroductionThis randomized clinical trial aimed to assess and compare the long-term clinical and radiographic outcomes of regenerative endodontic procedures (REPs) in treating nonvital immature permanent teeth using 2 intracanal medicaments.MethodsForty-five patients yielding a total of 50 anterior and posterior nonvital immature teeth were randomly divided into 2 groups. REPs using either nonsetting calcium hydroxide (Ca[OH]₂) (n = 25) or modified triple antibiotic paste (TAP) (n = 25) as intracanal medicaments were performed. NeoMTA Plus (Avalon Biomed Inc) was applied for coronal sealing. Cases were followed up clinically and radiographically for 36 months. The survival rate, success rate, and clinical outcome measures were analyzed. Preoperative and recall radiographs were evaluated for dimensional changes in root length, dentin thickness, apical diameter, and periapical radiolucency.ResultsAt the 36-month follow-up, the success and survival rates were 81.6% and 100%, respectively, in which 79.4% of cases showed complete resolution of periapical radiolucency with no significant difference between the nonsetting Ca(OH)₂ and modified TAP groups (P > .050). The cumulative changes in root length, root dentin thickness, and apical diameter throughout the study period were observed in 47.9%, 77.1%, and 89.6% of cases, respectively, with no significant differences between groups (P ≥ .39). Intracanal calcifications were detected in 60% of cases with no significant difference between groups (P = .77).ConclusionsREPs, using either nonsetting Ca(OH)₂ or modified TAP as the intracanal medicament, exhibited high success and survival rates over a follow-up period of 36 months with equally favorable clinical and radiographic outcome data.