Indian Journal of Dental Research

: 2019  |  Volume : 30  |  Issue : 5  |  Page : 810--815

Customization of attachments in tooth supported overdentures: Three clinical reports

Jyoti Devi, Poonam Goyal, Mahesh Verma, Rekha Gupta, Shubhra Gill 
 Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, Delhi University, New Delhi, India

Correspondence Address:
Dr. Jyoti Devi
E-603, Nav Sanjivan CGHS Ltd., Plot No. 1, Sector - 12, Dwarka, New Delhi - 110 078, Delhi


In elderly patients with few remaining teeth, overdenture is a good treatment option. Roots beneath the denture protect the alveolar ridge, offer proprioception and improve retention, stability and masticatory efficiency of dentures. Customization of attachments available is a viable alternative for some patients in which prefabricated attachments cannot be placed or in which cost is a factor; to improve the final outcome of the treatment. Due to competitive commercialization, implant treatment has become the norm in current dentistry and the concept of tooth supported overdentures has eclipsed, but with proper case selection, thorough treatment planning and modifications in the denture such as customization of attachments, amalgam stops, cross-linked teeth, and metallic mesh can be applied to prolong the longevity and success of the attachment overdenture prosthesis.

How to cite this article:
Devi J, Goyal P, Verma M, Gupta R, Gill S. Customization of attachments in tooth supported overdentures: Three clinical reports.Indian J Dent Res 2019;30:810-815

How to cite this URL:
Devi J, Goyal P, Verma M, Gupta R, Gill S. Customization of attachments in tooth supported overdentures: Three clinical reports. Indian J Dent Res [serial online] 2019 [cited 2022 May 23 ];30:810-815
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The idea of overdentures was established as a simple, cost-effective substitute to delay the development of edentulousness with augmented retention of prosthesis with remaining last few teeth finding its basis in De Van's dictum of perpetual preservation of what remains.[1] The tooth-supported overdenture concept thus stays to be a recognized treatment modality successfully applied onto implants, but it can always be planned for selective cases where implant placement is not possible.[2],[3],[4] According to Prieskel, abutment preparation for overdentures can be done in three ways: The preparation of root surface just above mucosal level (a) bare root face (b) dome-shaped gold coping; the use of attachments, and (c) thimble-shaped gold copings.[5] Masticatory efficiency, retention and stability of overdentures is better than with complete dentures supported on residual ridge and mucosa.[5],[6] Furthermore, natural teeth can have a proprioceptive and strong psychological significance for some patients.[7],[8]

Removable partial denture, complete denture, fixed-removable, and implant prosthesis can utilize numerous attachment designs, but it is important to choose an appropriate attachment for each discrete situation. By scrutinizing diagnostic casts, radiographs, and tentative maxillomandibular relation records, clinician can make significant interpretations which will influence the final selection.[9] The fabrication of tooth supported overdentures with semiprecision attachments can improve the longevity of prosthesis. Customization is also helpful for patients who cannot bear the cost of expensive attachments.[10],[11],[12] Furthermore, there are situations where remaining dentin thickness is less to accommodate postspace preparations required for prefabricated attachments.

In the current series of case reports, customization of tooth supported overdentures with different attachments was done. Each case was selected differently on the basis of number and distance between the abutment teeth present, their intra-arch alignment, and inter-arch space available.[13] Although clinical procedures done for tooth supported over denture in each case were similar including:

Periodontal treatment of remaining teethEndodontic treatment/restoration of abutment teethPostspace preparation of abutment teethTooth preparation and direct/indirect final impressions of abutments to receive copingsCementation of copingsFinal Impressions for denture fabricationSubsequent procedures were similar to fabrication of conventional complete denture.

 Case Reports

Case 1

A 45-year-old male reported with broken lower denture which was fabricated over prepared left and right mandibular canines only. Examination revealed partially edentulous arches with only teeth 11, 12, 21, 23, 33, and 43 remaining which were severely worn out. The preparation of the 33 was not ample which led to the repeated fracture of denture at the same point. Maxillary overdentures with dome-shaped and mandibular overdentures with thimble-shaped semiprecision attachments were planned because radicular precision attachments were overpriced for him. In addition, the amount of remaining dentin thickness was less.


Root canal treatments were completed for all teeth [Figure 1]a and [Figure 1]b. Tooth preparations were modified with chamfer margins, and 3 mm of radicular extensions with an anti-rotational groove were prepared in 33 and 43 [Figure 1]c and [Figure 1]d. Final impressions for coping fabrication were made using soft putty and light body elastomers (Affinis, Coltene Whaledent, Altstätten, Switzerland) [Figure 1]e. Four dome-shaped copings were made for maxillary arch, and two thimble-shaped copings with customized locator precision attachments were made for mandibular arch. Wax patterns for coping were fabricated on dies using blue inlay wax (Crown Wax, Bego, Bremen, Germany) [Figure 1]f. A square hard plastic cuboid container of 15 mm × 15 mm × 25 mm dimensions was used for the impression of locator overdenture implant attachment (LODI, Zest Anchors, CA, USA) using same putty and light body material [Figure 1]g. Two positive replicas free of any voids or nodules of the female component of locator attachment were obtained using self-cure acrylic resin (PATTERN RESIN™ LS, GC America Inc., IL, USA). Replicas were attached to the coping wax patterns with inlay were in a manner that both have a common path of insertion in the same transverse plane [Figure 1]h. Spruing was done away from the area where replica of female component of locator attachment was attached to the blue inlay wax coping. The casting was done in the conventional manner using Co-Cr alloy (Wirobond C, Bego, Bremen, Germany) and phosphate bonded investment material (Bellavest® SH, Bego, Bremen, Germany). Cementation of copings was done using luting Glass Ionomer Cement (GC Fuji I, GC America Inc., IL, USA) [Figure 2]a and [Figure 2]b. Dentures were then fabricated conventionally, with secondary impressions made using elastomeric impression material [Figure 2]c. Mesh was incorporated in the mandibular denture for providing additional strength to acrylic. Finished and polished dentures were inserted, adjusted, and postinsertion instructions were given [Figure 2]d. Male components of locator attachments were attached to the denture using chairside pickup technique with self-cure resin [Figure 2]e, [Figure 2]f, [Figure 2]g. Follow-up was done at intervals of 3 months for 1 year. At last, patient adapted well to the dentures without any complaints of sore mouth or breakage. Retention of mandibular denture was better than his previous one and esthetics were also improved with the maxillary denture [Figure 2]h.{Figure 1}{Figure 2}

Case 2

A 47-year-old male reported with difficulty in chewing food due to loss of upper teeth. On examination, 11, 13, 21, 22, 23 teeth and a splinted fixed denture prosthesis (FDP) from 37 to 47 was present [Figure 3]a, [Figure 3]b, [Figure 3]c. Orthopantomogram revealed metallic prefabricated screw posts in 13 and 23 teeth. The patient rejected the option of replacement of his FDP and implants prosthesis in maxilla because of the need for surgery, removal of natural teeth, the extended duration, and associated expenses. Tooth supported overdentures with dome-shaped copings, and radicular extensions were planned.{Figure 3}


After removal of metallic prefabricated screw posts from 13 to 23 teeth with the help of scaler (EMS scaler, ElectroMedicalSystems, Nyon, Switzerland) and artery forceps, roots of the remaining teeth were assessed for any fracture or decay. Chamfer margins were made around the 13 and 23 teeth and composite restorations were done in 11, 21, and 22. Root canals were thoroughly cleaned, shaped, and anti-rotational grooves were placed to receive the dome-shaped copings with radicular extensions into the roots for added retention due to limited inter-arch space [Figure 3]d. For an impression of postspace and fabrication of coping pattern resin (supplied as powder and liquid) is used. Polycarbonate plastic posts (Pinjet, Angelus, Londrina – Paraná, Brazil) were used for the direct impression of postspace. Petroleum jelly was applied in the postspace before starting the impression. Posts were dipped in liquid and powder was applied on the post and placed in the canal to make the direct impression and taken out when it is hardened. Once postspace impression is captured completely, resin is applied on the prepared tooth surface to fabricate dome-shaped coping directly in mouth [Figure 3]e. Subsequent steps were similar to as discussed in case history 1 [Figure 3]f and [Figure 4]a.{Figure 4}

As the opposing dentition was having a porcelain fused to metal multiple splinted FDP, high strength cross-linked acrylic teeth (Acry Rock, Ruthinium Dental, Rovigo, Italy) were used. Finished and polished dentures were inserted, adjusted, and instructions were given. The occlusal adjustment was done after 24 h. A round micromotor carbide bur was used to make holes of 2 mm diameter and 2 mm depth at the centric stops which were filled with non γ2-amalgam alloy (DPI Alloy, Dental Products of India, Mumbai, Maharashtra, India) supplied as pre-dosed capsules mixed in an amalgamator [Figure 4]b.

Follow-up was done at intervals of 3 months for 1.5 years. The patient adjusted well to the dentures without any complaints of pain or breakage of denture teeth, amalgam or of ceramic [Figure 4]c. Retention and stability of denture; and appearance of the patient was also improved [Figure 4]d. The patient was educated about the usage of interdental brush for the hygiene maintenance of FDP.

Case 3

A 50-year-old male reported with difficulty in chewing with only few teeth remaining. Intraoral examination revealed completely edentulous maxillary arch and mandibular arch with 33, 43, and 45 teeth abraded and worn out [Figure 5]a and [Figure 5]b. Maxillary complete denture and mandibular overdenture with semi-precision stud attachments on dome copings with small root extensions 3 mm in length were planned.{Figure 5}


For mandibular overdenture, dome-shaped coping was planned with respect to 45 and semi-precision micro stud attachments in 33 and 43. Procedure for customization was similar to as discussed in case history 2 [Figure 5]c, [Figure 5]d, [Figure 5]e, [Figure 5]f, [Figure 5]g, [Figure 5]h and [Figure 6]a, [Figure 6]b, [Figure 6]c, [Figure 6]d. Postinsertion instructions were given and follow-up was done at intervals of 2 months for 1 year. Patient's oral function improved with dentures without any complaints of difficulty in chewing, sore mouth or loss of retention [Figure 6]e and [Figure 6]f.{Figure 6}


Overdenture is a favored treatment modality for elderly patients with few remaining teeth. Tooth supported attachment overdentures may not be used by many dentists for reasons such as cost and lack of interest in understanding indications and applications of various designs of prefabricated attachments, fear of failure and frequent repairs, replacements or adjustments.[10],[11],[12] Due to the evolution of implants, the concept of tooth supported overdentures has eclipsed. In overdenture treatment, the teeth are included as part of the residual ridge which provides proprioception and psychological comfort to the patient.[7]

Attachment retained overdentures increase masticatory efficiency and provide added retention and support to the denture but the adequate zone of attached gingiva in a prerequisite.[14]

Once it is decided that a patient is to be planned for overdentures teeth to be retained as abutments should be selected. Careful selection of strategic attachment is important for the success of treatment.[1]

In the case reports described above, techniques for customization of the prefabricated attachments were described or customized copings were selected. For the first case, four dome-shaped copings for maxillary arch and two thimble-shaped copings with customized locator precision attachments were made for mandibular arch. Here, no compromise in the retention was observed with previous denture and patient's main concern was finances and repeated fracture. Hence, a replica of implant attachment was made by as he did not have to pay for attachment. Another advantage of partial customization is that if the amount of remaining dentin thickness in root was very less for radicular extension, it saved the tooth structure as postspace preparation was not required.[15] To prevent repeated fracture mesh was incorporated in the mandibular denture.[13] In the second case, dome-shaped copings with root extensions were made to accommodate previously prepared space for metal screw posts and limited inter-arch space. Customization was taken to the next level by strengthening the maxillary denture with metallic mesh and fabrication of amalgam stops to prevent wear of acrylic teeth against porcelain fused to metal restoration in mandibular arch.[16] For the third case, intermediate amount of vertical space was there so to accommodate semiprecision study attachments were placed on the dome-shaped copings with radicular extensions.

Micro stud attachments were used to prevent weakening of denture base. Female components were easily picked in self-cure resin at chairside.[17],[18],[19]

Advantages of overdentures include conservation of alveolar ridge, persistence of proprioception, increased denture retention and stability. Disadvantages include the obligation of increased oral hygiene maintenance to prevent caries and periodontitis. The overdenture tends to be over contoured in the position of natural teeth, more chances of fracture if insufficient acrylic thickness and appropriate amount of tooth reduction is not done. Encroachment of inter-arch space is another limitation.[1],[8]

Customization of attachments in tooth supported overdentures is challenging to execute, also demands perfection both at the dentist and technician level, so, but results achieved if planned correctly are worth the effort.[1] Factors influencing selection include buccolingual, mesiodistal and inter-arch space, bone support, material and type of opposing dentition, clinical skill and experience, individual inclinations, maintenance and cost.[20] Patient's attitude and enthusiasm toward treatment should also be assessed as patient selection is crucial for success. Attachment retained overdentures should be chosen carefully for those who understand limitations and benefits of overdentures.


Customization of attachments can be a simple and cost-effective alternative treatment to the use/modification of precision attachments for enhancing the retention, stability and function of tooth supported overdentures. Although tooth supported overdentures have the risk of caries development, periodontitis around abutments, and fracture of overdenture. But with proper patient selection, thorough treatment planning and modifications in the denture like making use of amalgam stops, cross-linked teeth, metallic mesh, radicular extensions; longevity and success of the attachment overdenture prosthesis can be achieved.


The authors would like to thank Dr. Sapna and Dr. Pooja for their suggestions and guidance in the laboratory steps.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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