Management of bruxism-induced complications in removable partial denture wearers using specially designed dentures: a clinical report.
Article Type:
Clinical report
Bruxism (Complications and side effects)
Bruxism (Care and treatment)
Partial dentures (Design and construction)
Partial dentures (Physiological aspects)
Baba, Kazuyoshi
Aridome, Kumiko
Pallegama, Ranjith Wasantha
Pub Date:
Name: CRANIO: The Journal of Craniomandibular Practice Publisher: Chroma, Inc. Audience: Academic Format: Magazine/Journal Subject: Science and technology Copyright: COPYRIGHT 2008 Chroma, Inc. ISSN: 0886-9634
Date: Jan, 2008 Source Volume: 26 Source Issue: 1
Geographic Scope: Japan Geographic Code: 9JAPA Japan

Accession Number:
Full Text:
ABSTRACT: In patients with a limited number of remaining teeth, bruxism force can be destructive for both the remaining teeth and periodontal structures. This paper reports the successful management of four such patients with severe sleep bruxism, using conventional removable partial dentures and specially designed, splint-like removable partial dentures called a night denture. The night denture was fabricated in two different designs, which depended upon the pattern of the remaining tooth contacts. The patients were followed up for 2-6 years using a night denture in either of the two designs. Within the limitations of these four reports of clinical cases, the night denture appeared to be effective in managing the problems related to sleep bruxism.


Sleep bruxism has been defined as "an oral habit wherein involuntary rhythmic or spasmodic nonfunctional gnashing, grinding, or clenching of teeth occurs." (1) It is potentially responsible for a variety of pains and dysfunctional conditions in the orofacial region and most commonly recognized bruxism related clinical problems are severe tooth attrition and increased tooth mobility. (2) Particularly in partially edentulous patients with a limited number of tooth contacts, bruxism force during sleep concentrates on the remaining teeth since removable partial dentures (RPD) are generally not worn during sleep.

Previously published literature regarding this clinical problem is scarce. A search of "PubMed," using keywords bruxism and dentures in human studies published in English yields only a handful of results (73 abstracts). Among these, none of the original research addressed a similar clinical problem, and only one of the 12 clinical reports described management of a similar case. (3) However, no attention was focused on bruxism-instigated complications in these reports.

While the use of appliances such as night guards is reported with respect to implant treatments, (4) no report addressed the possible concentration of the bruxism force on the remaining teeth in RPD wearers. The current report describes the successful management of four such patients using standard RPD in combination with a specially designed denture to be used exclusively during sleep. Since there is no validated effective method to control sleep bruxism, (5) the main focus of this clinical report was not to control sleep bruxism, but to protect the remaining teeth and periodontal structures from the concentration of bruxism force during sleep.

Clinical Reports

At the removable prosthodontic clinic, Tokyo Medical and Dental University, four partially edentulous patients with a limited number of tooth contacts between the remaining teeth sought treatment. Their principal complaint was pain and/or an uncomfortable feeling in their remaining teeth and periodontal structures upon waking in the morning. All these patients were using RPD, which were not worn during sleep. They were aware of their tooth grinding or clenching habits while sleeping and were diagnosed with sleep bruxism according to the criteria established by the American Academy of Sleep Medicine (AASM). (6) None of the patients reported having any significant medical problems. The age, gender, remaining teeth, chief complaints, and clinical findings for each patient are summarized in Table 1.

The principal strategy of the present approach was to provide the patients with an additional specially designed denture called the night denture, which was to be worn exclusively during sleep in place of the currently used RPD. These dentures were fabricated following standard RPD fabrication procedures. The night denture was designed for each patient according to the pattern of the remaining tooth contacts. For patients with tooth contacts between the remaining teeth, splint-like acrylic resin dentures were fabricated. These were designed to cover the occlusal surface of the remaining teeth and also to provide mucosal support from the residual ridges. For patients currently using conical crown-retained dentures (7) with tooth contacts existing only between copings and opposing teeth, acrylic resin-based dentures were fabricated in the same design as the currently used denture. In this report, the occlusal splint-type night dentures were fabricated for patients 1 and 2, and a conical crown-retained denture type was fabricated for patients 3 and 4.

Prior to delivering the night denture, complete verbal instructions were given to each subject on the necessity of using the night denture for the protection of the remaining teeth. The instructions included the possible risks Of nightly use of the denture, (8) including the fact that nightly coverage of periodontal tissue by the denture might lead to deteriorating periodontal disease, especially if the patient's oral hygiene is not acceptable, and that the quality of sleep might be disturbed while wearing the denture. Proper use of the night denture and the status of the patient's oral hygiene were confirmed to be acceptable immediately after the delivery of the dentures and reconfirmed every six months during the follow-up period.

Patient 1

The patient had a maxillary Class I edentulous area based on the Kennedy classification. She was concerned with a moderate mobility of her remaining maxillary anterior teeth and the uncomfortable feeling in these teeth upon waking. She was aware of her tooth-grinding during sleep for many years, and the tooth-grinding sounds were confirmed by her bed partner. The patient reported that she was afraid of breaking her anterior teeth during sleep, because of her tooth grinding habit. Physical examination revealed a grade two mobility of the remaining maxillary anterior teeth (8); however, the pocket depths of the teeth were within normal range and her general oral hygiene was excellent. Since the tooth contacts existed in relation to the remaining teeth, an occlusal splint-like

night denture with retentive clasps was fabricated for the patient. This denture had a resin occlusal coverage over the remaining anterior teeth with a resin base and increased the vertical dimension, resulting in a gap of three mm between the upper and lower incisal teeth.

In a six-year monitoring period, the patient used her night denture every night. Moderate wear was observed on the artificial teeth of the night denture during the period, which suggested sleep bruxism was still ongoing with the night denture in place. However, no further deterioration of the periodontal condition as measured by tooth mobility was noted, and the uncomfortable feeling in these teeth upon waking was well controlled (Figure 1).

Patient 2

The patient was provided with a mandibular conical, crown-retained denture at a private clinic. Five molars, which included the right second molar and bilateral first and second premolars, were restored with copings used as abutments for the denture. The patient was aware of the tooth grinding habit, which was confirmed by his bed partner, for many years and was concerned about the soreness of the mandibular anterior teeth upon waking up in the morning. The clinical examination revealed that tooth contacts existed only between anterior teeth when the denture was not in place and moderate to severe dentine exposure of the mandibular anterior teeth with no sign of periodontal disease. As in the first case, the patient was provided with an occlusal, splint-like night denture. The night denture was made entirely of clear heat polymerizing acrylic resin, and the occlusal vertical dimension was increased to the minimum amplitude. Since the copings were used as abutments, no retentive clasp was added. After the use of the night denture, severe attrition was noted on the occlusal surfaces of the night denture and grinding sounds were still confirmed by his bed partner. However, no significant complications, such as further attrition of the remaining mandibular anterior teeth or tooth soreness upon waking, were observed, and the patient used the night denture every night during a 3-year follow-up period. The status of the patient's oral hygiene was excellent and no sign of periodontal disease was found during this period (Figure 2).


Patient 3

The night dentures given to the third and fourth patients were of a different design from the previous patients. The third patient used a mandibular conical, crown-retained denture and was concerned about tooth pain in relation to the remaining mandibular right canine upon waking. The patient was fully aware that he had a clenching habit for a long period of time. Clinical examination revealed that when the denture was not in place, tooth contact was present only between the coping of the mandibular right canine and the opposite metal ceramic restoration which were worn due to sleep bruxism. The patient also reported a dull pain in the mandibular canine upon clinical examination. A resin-based denture, fabricated in the same design as the conical crown-retained denture, was used as the night denture.


The patient reported that he used the night denture every night during a follow-up period of three years and reported no tooth pain upon waking. While slight wear was found on the artificial teeth of the night denture at the follow-up clinical examinations, no further wear on the coping was observed. The patient also reported that when he forgot to use the night denture, he suffered from tooth pain in the right mandibular canine upon waking in the morning. The status of the patient's oral hygiene was excellent and no sign of periodontal disease was found during the follow-up period (Figure 3).

Patient 4

The patient had a newly fabricated conical crown-retained denture for her maxillary jaw. She was aware of her snoring and tooth grinding habit during sleep, which was confirmed by her bed partner. The patient also reported that she felt an uncomfortable feeling in the maxillary left premolar region upon waking in the morning. Clinical examination revealed that the tooth contact occurred only at the left premolar region between the copings and the opposite teeth in the absence of the denture. A resin-based denture was fabricated in the same design as the denture currently in use.

Soon after the delivery of the night denture, the major connector of the night denture was removed on the patient's request as she found it uncomfortable. A two-year follow-up revealed that the patient used the night denture every night and did not develop any complications in the remaining teeth related to sleep bruxism. The patient also maintained an excellent oral hygiene status, although grinding sounds were consistently reported by her bed partner (Figure 4).



An alternative method to manage bruxism-related complications would be to allow the patients to use their dentures during sleep. However, the use of night dentures is advantageous in comparison with this method for the following reasons. First, night dentures made of acrylic resin allow the even distribution of the bruxism force across the complete dental arch, thereby avoiding force concentration on the remaining teeth with minimal expense. Second, as the occlusal surfaces of the remaining teeth are covered by acrylic resin, they are protected from further attrition. Third, as night dentures are free of food debris, the risk of a periodontal disease due to denture plaque would be minimal. Fourth, severe attrition on the occlusal surface of the night denture can be easily repaired. Even if a refabrication is required due to excessive wear or fracture, the construction cost of an acrylic resin-based night denture is minimal. Therefore, the delivery of an inexpensive acrylic night denture is a practical approach to minimize the unfavorable effects of sleep bruxism in these patients, which include progression of tooth attrition, uncomfortable feeling or pain in the remaining teeth upon waking, and increased tooth mobility.

The potential unfavorable effects of wearing the night dentures during sleep on the periodontal tissues were initially a cause for concern. (9) However, the use of night dentures that are free of denture plaque, a well-controlled oral hygiene, and the appropriate distribution of bruxism force across the dental arch may have minimized this risk. In fact, sleep bruxism-related complications in all these subjects were successfully managed by using night dentures throughout the follow-up period.

As for the weakness of this study, we performed no physiological measurements to assess bruxing activity. Although all patients were diagnosed with sleep bruxism according to internationally accepted criteria, (6) lack of the measurements did not allow for objective evaluation of the effects of night dentures on sleep bruxism levels. While the literature suggests that nightly use of dentures during sleep is associated with lower sleep bruxism levels, (10,11) moderate to severe wear observed on the artificial teeth of the night dentures and the reports of grinding sounds by the bed partners suggest that the patients continued to grind their teeth after delivery of the night dentures.



Bruxism-related complications with regard to remaining teeth were well managed in patients while using the night denture during considerably longer follow-up periods. In the absence of a simple and practical technique to achieve similar results and within the limitation of four clinical reports, the night denture may be recommended for patients having a few remaining occlusal contacts with sleep bruxism-induced complications.

Manuscript received September 8, 2006; accepted November 7, 2006


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(6.) American Academy of Sleep Medicine, The International Classification of Sleep Disorders 2, American Academy of Sleep Medicine, Westchester, IL; 2005.

(7.) Bergman B, Ericson A, Molin M: Long-term clinical results after treatment with conical crown-retained dentures. Int J Prosthodont 1996; 9:533-538.

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(10.) Okeson J, Philips B, Berry D, Cook Y, Paesani D, Galante 1 : Nocturnal bruxing events in healthy geriatric subjects. J Oral Rehabil 1990; 17:411-418.

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Kazuyoshi Baba, D.D.S., Ph.D.; Kumiko Aridome, D.D.S., Ph.D.; Ranjith Wasantha Pallegama, D.D.S., Ph.D.

Dr. Kazuyoshi Baba received a D.D.S degree in 1986 and a Ph.D. degree in 1991 from Tokyo Medical and Dental University. He is currently professor and chair at the Department of Prosthodontics, Showa University. He is a supervisor); doctor of the Japanese Prosthodontics Society. He has published more than 50 publications, including 30 papers in English. The primary focus of his study is sleep bruxism.

Dr. Kumiko Aridome received a D.D.S degree in 2001 and a Ph.D. in 2005 from Tokyo Medical and Dental University. She is currently an assistant professor at the Department of Removable Prosthodonties, Graduate school, Tokyo Medical and Dental University.

Dr. Ranjith W. Pallegama received a B.D.S. degree in 1997 from the University of Peradeniya, and received a Ph.D. in 2005 from the Tokyo Medical and Dental University. He is currently a senior lecturer in physiology attached to the Faculty of Dental Sciences, University of Peradeniya, Sri Lanka.

Address for correspondence: Dr. Kazuyoshi Baba Dept. of Prosthodontics School of Dentistry Showa University 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515 Japan E-mail:
Table 1
Chief Complaints and Clinical
Findings for Each Patient

                           Patient 1              Patient 2

Age                           68 yrs.                61 yrs.
Gender                         Female                  Male

Chief complaints        Uncomfortable          Soreness of the
                        feeling in her         mandibular anterior
                        anterior teeth         teeth upon waking
                        upon waking

Clinical findings       Grade 2 mobility       Moderate to
                        of the remaining       severe dentine
                        maxillary anterior     exposure of the
                        teeth                  mandibular anterior

Remaining natural            321   123               321   123456
teeth or restored        7654321   1234567        7 4321   12345

Location of tooth            321   123                21   12
contacts without             321   123                21   123

Type of night denture   occlusal splint type   occlusal splint type

                          Patient 3            Patient 4

Age                          75 yrs.             58 yrs.
Gender                         Male               Female

Chief complaints        Dull pain in the     Uncomfortable
                        mandibular right     feeling in the
                        canine upon          maxillary left
                        waking               premolar
                                             upon waking

Clinical findings       Flattened occlusal   Tooth contact
                        contact surface      present only
                        on the right         between the
                        canines              left first

Remaining natural        321   123   67      6        45
teeth or restored          3   34    8       654321   123456

Location of tooth          3                          4
contacts without           3                          4

Type of night denture   conical crown-       conical crown-
                        retained denture     retained denture
                        type                 type
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