“Evaluation of the outcome of treatment with liquid supported complete denture and conventional complete denture for the management of long term denture wearer patient having flabby resorbed mandibular ridge- A case report”

INTRODUCTION

‘Flabby’ridge is a superficial mobile soft tissue found on maxillary or mandibular alveolar ridges. It mainly occurs in long term denture wearers or from trauma from ill fitting dentures. It is seen more often in the anterior region and sometimes in posterior regions of residual ridges. Histologically it consist of hyperplastic mucosal tissue underlined by fibrous connective tissue along with dense collagenised connective tissue.^[1]

Success of complete denture treatment mainly depends on the health and condition of the hard and soft tissues which form the denture-bearing areas. The health of denture bearing tissue deteriorates due to prolonged use of ill fitting dentures leading to fibrous ridges which causes poor denture stability and inadequate retention. Also the masticatory forces can displace this denture-bearing tissues, leading to change in denture positioning and thus loss of peripheral seal.^[2]

Flabby ridges can be managed by surgical removal of fibrous tissues, using Implant retained prosthesis or by Conventional prosthodontics. Treatment option has to be chosen depending on health of the patients and need, extent of fibrous tissues, affordability and skill of the dentist.

With Conventional treatment option, recording of such mobile tissues is a challenge for prosthodontist. Forces during impression making can cause distortion of the fibrous mobile tissue. Various spacer designs such as double spacer for special tray, selective perforation of custom tray, controlled lateral pressure technique- window technique and palatal splinting of tray using two tray technique have been used to record the flabby tissues.^[3] All these procedures are technique sensitive and have to be followed while fabrication of complete dentures along with neutral zone technique and by giving balanced occlusion.

Liquid supported denture is less commonly followed conventional approaches to manage such difficult clinical situation. Advantages of liquid supported dentures include good adaptation of denture base to the mucosa under forces due to hydrodynamics of the liquid thus improving support, retention and stability. Stress distribution of masticatory forces over a broader area which reduces tissue overloading. Therefore it prevents trauma or ulceration of soft tissues and increases comfort level and ultimately good patient acceptance.

Case presentation:

A 71 year-old-female patient reported complaining about the ill-fitting dentures. The patient gave history of wearing complete dentures from past 15 year. Her main complaint was about poor fit of exiting denture and inability to eat food. Patient gave a history of hypertension and diabetes since last 10 year and is on medication for the same.

Intraoral examination revealed completely edentulous maxillary and mandibular arches with the presence of flabby tissues in the mandibular anterior region (Figure 1a). Also the patient had Angles class II ridge relation. Considering the patient’s systemic health, age and economy it was decided to carry out treatment conventionally, so the mandibular liquid-supported complete denture was thought. For the comparative evaluation along with liquid supported denture one more mandibular conventional complete denture was fabricated following the routine process of fabrication. The treatment plan for study has been approved from institutional ethical and research committee.

Treatment:

Maxillary primary impression was made using impression compound whereas mandibular primary impression was made with alginate impression material (Prime Dental products pvt. Ltd., Mumbai, India). Custom trays were fabricated on primary casts. Border moulding was performed by using low fusing impression compound (DPI, Mumbai) and final impressions were made with light body silicone impression material (Aquasil, Dentsply/caulk) (Figure 1b). Mandibular master cast was duplicated using agar agar material and the second cast was used for fabrication of the conventional complete denture.

Temporary denture bases were fabricated using acrylic resin. Jaw relations were recorded following the routine technique and transferred on to semiadjustable articulator (Hanau Widevue -192 series, model# HANAU 014809-000) (Figure 1c). In the next appointment neutral zone was recorded for mandibular arch using swallowing technique. Putty index of compound occlusal wax rim after neutral zone recording was used as guide for arrangement of teeth in balanced occlusion (Figure 1d). Due to the presence of class II arch relation; it was decided to give balancing ramps distal to second molar on mandibular trial dentures (Figure 1e).after try-in maxillary and mandibular complete dentures were ready for processed using routine process of fabrication.

For the fabrication of liquid supported mandibular denture, polyethylene sheet (Biostar, Germany) of 1.5mm thickness was heat pressed on the mandibular master cast. The sheet was cut and made 2mm short of the sulcus which acted as a temporary spacer (Figure 1d). After dewaxing the temporary polyethylene sheet (thick sheet) was placed on the mandibular cast and lubricated using Vaseline so that sheet could be easily retrieved. The denture was processed using PMMA heat cure acrylic (DPI, Mumbai) along with the sheet inside. The mandibular denture was then finished and polished (Figure 2a).

In next appointment the denture with polyethelene sheet was placed in to the patient’s mouth and checked for retention, support and stability (Figure 2b). The patient was advised to wear the denture for 10-14 days.

After two weeks, the polyethylene 1.5mm sheet was removed from the mandibular denture. A high viscosity silicon impression of the impression surface of the denture was registered to prepare a cast. The impression of obtained cast was made and poured to get positive replica of denture impression surface so that exact junction of the sheet and denture base could be seen. On this new cast, a 0.5mm thick polyethylene sheet (thin sheet) was then vacuum heat pressed. Thin sheet was then accordingly cut and placed on to the impression surface of the denture from where the thick sheet was removed. It was then sealed using Cyanoacrylate adhesive and autopolymerizing acrylic resin (Figure 2c).

Two holes were drilled on the buccal flange of the denture using round bur for injection of viscous liquid, glycerine. The space difference created due to the replacement of a thick sheet with a 0.5mm thin sheet was then filled with glycerine. Glycerine was injected from one hole till it comes out from another hole, thus the created space by replacement of thick sheet is filled with glycerine liquid. After that one hole was sealed with autopolymerizing resin and occlusal vertical dimension was verified by placing the denture in the patient’s mouth. Once the occlusal vertical dimension was achieved other hole was sealed with autopolymerizing resin. The mandibular liquid supported denture was inserted in patient’s mouth. After postinsertion instructions the patient was educated about special care of polyethylene sheet and also about the cleaning of tissue surface of denture using cotton pellet. Patient was advised not to use the hard brush for cleaning as it might damage the polyethylene sheet.

The Patient was recalled after the first day then after a week. The patient was satisfied with the aesthetics and functions of prosthesis and was advised for regular recall visits.

In third week patient was introduced with mandibular conventional complete denture and insertion of the denture was carried out. Patient satisfaction with the denture was evaluated and advised for regular recall visits.

Outcome and follows up:

In fourth week once the patient got adapted to conventional complete denture she was asked to compare both mandibular denture. Both the dentures were comparable in terms of retention, stability, support along with function and aesthetics. Patient was satisfied with both the dentures but there was more comfort with liquid supported denture because of soft and gentle denture base (Figure 2d). The comparison of number of post-insertion checkups and amount of correction required during checkups were less for liquid supported denture. Patient had somewhat difficulty in maintaining the impression surface of the liquid supported mandibular denture as compared with conventional denture. All the response by the patient was record in questionnaire format for the evaluation of both dentures.

Discussion

The presence of flabby tissue in anterior region of mandibular ridge leads to uneven distribution of forces that can cause tissue soreness. These problems can be conventionally treated by fabricating liquid supported balanced complete dentures.

The liquid supported denture is based on principle that, when masticatory forces are applied on denture it adapts to the altered form of mucosa because of hydrodynamics of the viscous liquid (Figure 2e). This design of liquid supported denture acts as a continuous reliner for the denture base. It also helps in preservation of denture bearing tissues.⁴

Davidson CL and Boere G in 1990 stated that with liquid supported denture there was even broad stress distribution of masticatory forces which reduces tissue overloading. Other merits of liquid supported denture were prevention of soreness along with increased comfort level. It also eliminates the disadvantages of soft liners that is mainly poor bond strength to acrylic and colonization of candida, etc.⁴

In this case, clear polyethylene thermoplastic sheet (Biostar vaccum forming machine, Germany) and glycerin liquid as viscous liquid was used for liquid supported denture. Both are biocompatible in oral cavity.

Boere G, de Koomen H and Davidson CL in 1990 carried out a clinical study on 11 patients wearing liquid-supported dentures. The most important conclusions of this study were that, it was possible to fabricate a liquid-supported denture that would be comfortable along with proper retention. Also the liquid supported denture could provide a solution to problematic prosthodontic situations.⁵

In the present case questionnaire format for the evaluation of both dentures was used to record patient response and we could note that there was same level of acceptance for conventional and liquid supported dentures which leads to a conclusion that liquid supported denture can be one of the treatment modality for management of the flabby residual ridges.

Certain precautions should be followed during fabrication of liquid supported denture or else it could be a failure. Minimum thickness of denture base should be 3mm to provide proper space for liquid and sheet. Sealing of polyethelyne sheet should be proper and should be checked for microleakage. If there is any leakage of liquid, patient should report to the dentist immediately and the denture should be refilled and sealed back using patients preserved master cast. Proper postinsertion instructions and maintenance of liquid supported denture should be given to the patient.

LEARNING POINTS

• Management of flabby ridges in completely edentulous patients is a prosthodontic challenge.

• Surgical removal of the fibrous tissue may not always be possible due to systemic condition of the patient and implant retained prostheses may not be an option for all patients.

• Conventional prosthodontics using liquid supported complete dentures can improve the patient’s acceptance due to even distribution of forces with increased level of comfort.

• Comparative evaluation showed that patient was equally satisfied with both liquid supported and conventional complete dentures. The level of satisfaction with liquid supported complete denture was slightly higher, so could be easily adopted to provide satisfactory dentures to the needful patients.