One step polymerizing technique for fabricating a hollow obturator

PurposeAlthough a closed hollow obturator is often applied to post maxillectomy patients, it has a few problems such as complexity of fabrication and water leakage to inside. A one step curing technique to fabricate a closed hollow obturator by constructing a small hollow bulb made by two thermoplastic resin sheets is described in the present report.MethodsIn the one step curing technique, after dewaxing the wax denture fabricated conventionally, one size smaller hollow body was fabricated with two thermoplastic resin sheets and set into the investment mold as a core. Then the circumferential part of obturator was cured by the pour type resin.This technique was used to fabricate an obturator prosthesis in a 60-year-old post-maxillectomy patient. The weight of this obturator was well controlled and the definitive prosthesis weighed 22 g. At a one year follow-up, the obturator fared well without any water leakage or breakage.ConclusionsThis technique allows the fabricator to control the thickness and weight of the obturator by the amount of relief provided by the hollow bulb. It also rectifies the disadvantages of the closed hollow obturator such as water leakage and complexity of fabrication.     

Water absorption characteristics of two types of acrylic resin obturators

STATEMENT OF PROBLEM: The mechanisms of water accumulation in the inner space of a closed hollow obturator are not understood, and it is not known whether the porosity of acrylic resin is involved in these mechanisms. PURPOSE: The purpose of this study was to evaluate water absorption by solid and closed hollow obturators and to determine the mechanisms of water accumulation in the inner space of the closed hollow obturator. MATERIAL AND METHODS: Twenty solid and 20 closed hollow spherical specimens (30 mm in diameter) were fabricated from heat-polymerized acrylic resin (Acron Clear). Closed hollow specimens consisted of 2 hemispheres (30 mm in diameter, 1.5 mm in thickness) joined with autopolymerizing resin (Unifast II). Ten solid and 10 closed hollow specimens were immersed in distilled water at 37 degrees C, while the other specimens were stored in an atmosphere of 100% relative humidity at 37 degrees C. Each specimen was weighed every 24 hours for 180 days, and weight changes between each group were compared by 2-way ANOVA and the Tukey HSD test. Split-plot design ANOVA was used to compare the course of the weight change over 180 days (alpha=.05). RESULTS: The weight of the closed hollow specimens increased immediately and became saturated by day 30, with an increase of 1.44% from the initial weight. Water accumulation was not observed inside the closed hollow specimen during the 180-day storage period. The weight of solid specimens increased more slowly than that of closed hollow specimens; by day 180 the weight of the latter had increased by 1.16%. However, no significant difference in changes in mean mass of the same type of specimen was observed between the 2 storage conditions. CONCLUSION: These results suggest that water accumulation inside a closed hollow obturator is unrelated to the water absorption properties of the acrylic resin.     

Difference in water accumulation patterns between solid and closed hollow obturators under a thermal cycle

ABSTRACT: Water accumulation in the hollow space of a maxillary obturator is a continuing problem, and it is unclear whether the porosity of acrylic resin is involved in the mechanism. The purposes of the study were to evaluate the effect of a hollow space in the resin obturator on water sorption under a thermal cycle and to determine factors associated with water accumulation in the obturator. Twenty solid spheres (30-mm diameter) and 40 hemispheres (30-mm diameter, 1.5 mm thickness) were fabricated from heat-polymerized acrylic resin. Closed hollow specimens consisted of 2 hemispheres joined with autopolymerizing resin. Ten solid and 10 closed hollow specimens were immersed in distilled water, whereas the other specimens were stored at 100% relative humidity. Each specimen was thermocycled (5°C-37°C) with a dwell time of 12 hours and weighed every 12 hours for 180 days. Of the 20 closed hollow specimens, 16 showed no water accumulation (8 in distilled water, 8 at 100% humidity). The weight of these specimens became saturated by day 90, with increases from the initial weight of 1.41% at 5°C and 1.36% at 37°C. By day 180, the weights of the solid specimens had increased by 0.96% at 5°C and 0.94% at 37°C. Weight fluctuation associated with temperature was observed for both types of specimens and for all storage conditions. It is concluded that water accumulation inside a closed hollow obturator is not directly related to the water absorption properties of the acrylic resin but is related to thermal damage of the obturator.     

Prosthetic rehabilitation of a completely edentulous patient with palatal insufficiency.

This article presents a case report of a completely edentulous patient with palatal insufficiency successfully rehabilitated with closed hollow bulb obturator prosthesis and also describes a simple technique for fabricating a two-piece hollow bulb obturator that allows for control of the bulb's wall thickness and weight of the prosthesis.     

Fabrication of a hollow obturator as a single unit for management of bilateral subtotal maxillectomy

Prosthetic rehabilitation with an obturator for a total or subtotal maxillectomy patient is a challenging task, as there are little or no residual maxillary structures to depend on for support, retention, and stability of the prosthesis. This clinical report describes the prosthodontic management of a patient operated on for a bilateral subtotal maxillectomy secondary to ameloblastoma of the palate with a closed hollow obturator. The processing technique described in this article to fabricate the hollow obturator is a variation of other well-known techniques. The variation comprises the use of a wax bolus to maintain a predictable internal dimension for a hollow obturator. This technique allows fabrication of a complete hollow obturator prosthesis as a single unit in heat-polymerized acrylic resin using a single-step flasking procedure.     

Fabrication of a closed hollow obturator

This article describes a technique for fabricating a closed hollow bulb obturator. It allows for control of the bulb's wall thickness and weight while not requiring any additional materials or time-consuming steps to the conventional processing procedures.     

An esthetic technique to fill screw-retained fixed prostheses

Currently, many composite materials have been used in the filling of access openings for screw-retained implant prosthesis. The main disadvantage of these materials is the compromise in esthetics that they place on the implant crown. An additional disadvantage is leakage of bacterial contaminants around traditional light-cured composites placed in the screw access hole. This article introduces a technique that uses opaqueing composites and the expansion properties of panacea (Zeza Inc, Chester, NY) resin to help remedy these problems. The fabrication of the silicone obturator is explained in previous literature. By following this technique, the dentist can use resin to decrease microleakage and opaqueing composite to improve esthetics.     

Esthetic abutment design for angulated screw channels: A technical report

Angulated screw channel system abutments (ASCs) have recently been introduced to address the problem with visible screw access that may compromise esthetics. ASCs allow the screw access to be modified up to 25 degrees relative to the implant axis. However, a widened channel, which may cause thinning of the facial ceramic, is needed at the implant screw head to allow for proper engagement of the screwdriver. This technical report introduces a custom titanium insert design, the Satoshi Sakamoto (SS) abutment. The SS abutment consists of a custom titanium metal insert and zirconia coping in which the access hole is located in an esthetic position with an ASC system. The SS abutment results in a crown with more normal crown dimensions that also provides more space for the soft tissues. This SS abutment design allows clinicians to obtain screw-retained restorations with optimal esthetics and mechanical strength.     

Closed Hollow Bulb Obturator—One‐Step Fabrication: A Clinical Report

A method is described for the fabrication of a closed hollow bulb obturator prosthesis using a hard thermoforming splint material and heat‐cured acrylic resin. The technique allowed the thickness of the thermoformed bulb to be optimized for weight reduction, while the autopolymerized seal area was covered in heat‐cured acrylic resin, thus eliminating potential leakage and discoloration. This technique permits the obturator prosthesis to be processed to completion from the wax trial denture without additional laboratory investing, flasking, and processing.     

赝复体修复上颌骨缺损语音效果的评价

目的采用患者自我评价和主观判听的主观评价方法 ,评价赝复体修复上颌骨缺损的语音效果,并比较开放式赝复体和封闭式赝复体语音效果的差异。方法对9例单侧上颌骨缺损患者的录音资料进行患者自我评价;由判听者进行过高鼻音程度及语音清晰度的判听。对评价结果进行单因素方差分析。结果戴用开放式赝复体或封闭式赝复体时,患者对语音效果的自我评价明显高于未戴赝复体时,过高鼻音判听分数明显降低,语音清晰度明显升高,差异具有统计学意义（P〈0.01）。戴用开放式赝复体与封闭式赝复体时,患者对语音效果的自我评价、过高鼻音判听分数以及语音清晰度的差异无统计学意义（P〉0.01）。结论赝复体可显著降低上颌骨部分缺损患者的过高鼻音程度,改善患者的语音清晰度,患者的满意度较高,且开放式赝复体与封闭式赝复体的效果相近。     

Using a Porcelain Furnace to Debond Cement‐Retained Implant Crown from the Abutment after Screw Fracture: A Clinical Report

When a screw fracture occurs on a cement‐retained, implant‐supported restoration, the abutment and restoration are completely separated from the implant's internal connection. Traditionally, an access hole is drilled through the crown to retrieve the broken screw, and the restoration can be placed again as a screw‐retained restoration. This clinical report documents a patient whose broken abutment screw was retrieved from the restoration by burning off the cement and separating from the abutment without drilling an access hole.     

种植义齿固定螺丝封闭后微渗漏的定量测定

目的用定量测定葡萄糖含量的方法检测种植义齿固定螺丝孔的微渗漏，并比较四种光敏树脂对固定螺丝孔的封闭性。方法制备20个钛合金中空半圆柱体试件（高6mm，厚1mm，直径3mm，上1／2表面烤瓷0．5mm），试件内表面喷砂＋瓷层酸蚀处理后分成四组，分别用四种光敏树脂进行封闭，用葡萄糖氧化酶法（COD-POD法）测定各组微渗漏情况。结果四组试件间微渗漏具有显著差异（P〈0．01）。结论封闭材料是影响固定螺丝孔微渗漏的一个重要因素；GOD-POD法是一种能定量测定种植义齿固定螺丝孔微渗漏的方法。     

An alternative method for fabricating a closed hollow obturator: a clinical report

This article describes a procedure in which the fabrication of a closed hollow obturator can be made with three sections of a denture flask by using silicone. Ease of fabrication while controlling the thickness of the hollow portion and eliminating leakage and discoloration are major advantages of this technique while minimizing laboratory and clinical appointment time.     

Prosthetic rehabilitation of a patient after partial maxillectomy: A clinical report

Malignant melanoma of the oral cavity is very rare. This clinical report describes a method for prosthetic rehabilitation of a patient with malignant melanoma of the palate following partial maxillectomy with a closed hollow interim obturator.     

Obturator fabrication incorporating computer-aided design and 3-dimensional printing technology: A clinical report

This article reports an approach to fabricating a maxillary obturator using the computer-aided design and computer-aided manufacturing (CAD-CAM) process. The maxillary definitive cast and the trial tooth arrangement were separately scanned and superimposed. The virtual cast created from the scan data was surveyed, and the framework was designed using specific software. The definitive cobalt-chromium framework was fabricated by using 3-dimensional (3D) selective laser sintering (SLS) technology. After framework trial placement, the definitive obturator prosthesis was processed using conventional heat-polymerizing resin with the lost-wax processing technique. Using CAD technology and 3D metal printing resulted in improved fit, function, and esthetics for the definitive obturator prosthesis.     

Construction of a maxillary prosthesis with a hollow obturator by the balloon technique and a case report

The authors devised a new method for making a maxillary prosthesis with a hollow obturator, which was named the Balloon Technique. This new technique has a number of advantages over the conventional method in that it not only facilitates the molding of a soft plastic hollow obturator in a single process, but also simplifies the trial fitting of the completed obturator. Furthermore, it makes possible firm adhesion of the hollow obturator and the denture base by the hot-melt method while the denture base resin is cured. Finally, the completed maxillary prosthesis is extremely light.     

A light-cured interim obturator prosthesis. A clinical report

A new method of making a maxillary interim hollow obturator prosthesis is presented. The light-cured resin allows the dentist to make and deliver the prosthesis at the same visit with minimal time and equipment.     

Safe Removal of a Broken Abutment Screw with Customized Drill Guide and Rotary Instrument: A Clinical Report

This clinical report introduces a method for safe retrieval of a broken implant abutment screw. A reverse‐tapping rotary instrument has been introduced in the market and is widely used to retrieve broken screws; however, it is difficult to use the rotary instrument unless an access hole for engagement of the rotary instrument is positioned directly on the center of the top of the broken screw remnant. Poor visibility is another limitation to make an access hole. To keep the position of the rotary instrument at the center of the broken screw, a customized drill guide was fabricated, modifying an implant impression coping with self‐cured acrylic resin, all easily found in daily practice. The broken screw was easily removed, not damaging the internal threads of the implant. This technique could be applied to most implant systems when a specific removal kit for each implant system is not prepared.     

Porcelain Fracture Resistance of Screw‐Retained,Cement‐Retained,and Screw‐Cement‐Retained Implant‐Supported Metal Ceramic Posterior Crowns

Purpose: The purpose of this in vitro study was to compare the porcelain fracture resistance between screw‐retained, cement‐retained, and combined screw‐ and cement‐retained metal–ceramic (MC) implant‐supported posterior single crowns; and to investigate the effect of offsetting the occlusal screw‐access opening on porcelain fracture resistance of screw‐retained and cement‐retained MC implant‐supported posterior single crowns. Materials and Methods: Forty standardized MC molar‐shaped restorations were fabricated. The 40 restorations were divided into four groups (SRC, SRO, CRP, and CSC) of 10 specimens each. Group SRC: screw‐retained, screw‐access hole placed in the center of the occlusal surface; Group SRO: screw‐retained, screw access hole placed 1 mm offset from the center of the occlusal surface toward the buccal cusp; Group CRP: cement‐retained, zinc phosphate cement was used; Group CSC: cement‐retained with a screw‐access hole in the center of the occlusal surface. The screw‐retained restorations and abutments were directly attached to 3i implant fixtures embedded in acrylic resin blocks. Subsequently, all test specimens were thermocycled and vertically loaded in a universal testing machine at a crosshead speed of 2 mm/min until fracture. Mean values of load at fracture (in N) were calculated in each group and compared with a one‐way ANOVA and Tukey's Studentized test (α= 0.05). Results: Mean values of loads required to fracture the restorations were as follows (N): Group SRC: 1721 ± 593; Group SRO: 1885 ± 491; Group CRP: 3707 ± 1086; Group CSC: 1700 ± 526. Groups SRC, SRO, and CSC required a significantly lower force to fracture the porcelain than did the CRP group (p < 0.05). Conclusion: The cement‐retained restorations showed significantly higher mean fracture loads than the restorations having screw‐access openings in their occlusal surface. The position of the screw‐access hole within the occlusal surface did not significantly affect the porcelain fracture resistance.     

Fabricating a Hollow Obturator with Light-Cured Resin System

Tumor resection of a cancer lesion produces maxillary defects that can be easily restored with an obturator to close the defect area. Postsurgical maxillary defects predispose a patient to hypernasal speech, fluid leakage into the nasal cavity, and impaired masticatory function. Therefore, the primary aims of prosthetic rehabilitation in total and partial maxillectomy patients include: separation of oral and nasal cavities to allow adequate deglutition and articulation, possible support of orbital contents and support of soft tissue to restore mid-facial contours. A method of fabricating a simple hollow obturator for maxillectomy patients is described. The use of a relatively long-lasting light cure resin materials in making obturators allows stable, comfortable, and effective obturation. The hollow prosthesis is lightweight and sufficiently flexible to allow relatively simple placement in retentive undercut regions.