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 Table of Contents  
Year : 2020  |  Volume : 7  |  Issue : 3  |  Page : 156-163

Clinical practice preferences of Australian and New Zealand practitioners in the implant management of the edentulous mandible

Department of Prosthodontics, Adelaide Dental School, The University of Adelaide, South Australia, Australia

Date of Submission17-Feb-2020
Date of Decision10-May-2020
Date of Acceptance11-May-2020
Date of Web Publication07-Aug-2020

Correspondence Address:
Prof. James Dudley
Adelaide Dental School, Adelaide Health and Medical Sciences Building, The University of Adelaide, Adelaide
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/sjos.SJOralSci_9_20

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Introduction: Mandibular edentulism remains a widespread health burden with a variety of available treatment modalities, but without an accepted single best practice approach. The purpose of the present study was to survey clinical practice preferences of Australian and New Zealand practitioners in the management of patients with edentulous mandibles with a specific focus on the use of dental implants.
Materials and Methods: A questionnaire comprising thirty questions was developed and administered online via a unique web link sent to all known Australian and New Zealand general dental and specialist professional membership bodies.
Results: Responses received from the members of five of the ten membership bodies constituted 7.35% overall response rate. Respondents who had undertaken implant training and were involved in implant treatment of the edentulous mandible totaled 65.5%. The pattern of referral to specialists for surgical implant placement varied according to the type of prosthesis being constructed. Of 111 respondents, 72% preferred two implants for mandibular implant overdentures (MIODs), whereas 97% of 98 respondents preferred four or more implants for a mandibular fixed complete implant denture. The main reasons for choosing MIOD instead of fixed complete implant denture were cost, patient preference, and available jaw bone.
Conclusions: The highest level of education in implant dentistry varied significantly between respondents and was potentially reflected in the wide variety of reported treatment approaches. Even within a specific implant prosthesis type, there was no universally accepted modality of management. Future research should focus on alternative survey strategies for obtaining important data representative of the total practicing population.

Keywords: Implants, mandibular edentulism, mandibular fixed complete implant denture, mandibular implant overdenture, mandibular removable complete denture

How to cite this article:
Dudley J, Mughal F. Clinical practice preferences of Australian and New Zealand practitioners in the implant management of the edentulous mandible. Saudi J Oral Sci 2020;7:156-63

How to cite this URL:
Dudley J, Mughal F. Clinical practice preferences of Australian and New Zealand practitioners in the implant management of the edentulous mandible. Saudi J Oral Sci [serial online] 2020 [cited 2021 Apr 22];7:156-63. Available from: https://www.saudijos.org/text.asp?2020/7/3/156/291610

  Introduction Top

Edentulism is a key indicator of the oral health status of populations and is associated with a reduced quality of life.[1] The prevalence of edentulism has declined over the past 50 years in most Western nations[2] including in Australia[1] where the National Survey of Adult Oral Health (2004–2006) reasoned the decline was related to the passing of generations that experienced an epidemic of complete tooth loss during the first half of the twentieth century.[3] Despite its decline, edentulism is a significant health-care burden.

The removable complete denture is the classic therapy for edentulism; however, there is considerable variation in individual patient adaptation and tolerance. The original use of osseointegrated dental implants to support fixed mandibular prostheses provided significant functional and satisfaction benefits for edentulous patients, particularly in maladaptive denture wearers.[4],[5]

Since this time, a multitude of additional implant uses have been implemented with success to the point that some groups have proposed the two-implant overdenture as the ''gold standard'' for the treatment of the edentulous mandible;[6],[7] however, prosthodontic complications do occur.[8] Early studies were reported on the long-term success of osseointegrated implants in the management of mandibular edentulism with fixed prostheses,[5] but patient financial restrictions and reluctance to undergo the required procedures may discourage edentulous patients from pursuing implant treatment.[9] Financially, the traditional mandibular removable complete denture (MRCD) presents advantages over implant alternatives.[10]

Clinicians are often faced with a difficult task in assisting edentulous patients to decide on the most appropriate treatment option. Certainly, the decision is multifactorial and while some studies claim the superiority of some implant treatments,[11] others found little or no difference.[12] The decision is often further complicated in the aging population where there are additional medical, compliance, and adaptive capacity factors to consider.[13]

There is no universally accepted treatment modality for the rehabilitation of the edentulous mandible using implants as echoed in the international survey conducted by Carlsson who speculated that prosthodontic traditions and economic factors relating to each specific country were probably the most important reasons for the significant variation.[14] In addition, factors such as dental education, treatment results, economic status, dental insurance systems and rebates, national and state regulations, and patient psychosocial and cultural factors influence the treatment decision.[14]

Ultimately, treatment needs to be provided for our edentulous patients based on a knowledge of the complete range of treatment options, individual patient assessment, informed consent, and using principles of best practice. The purpose of the present study was to survey the clinical practice preferences of Australian and New Zealand practitioners in the management of patients with edentulous mandibles with a specific focus on the use of dental implants.

  Materials and Methods Top

Ethics approval was obtained from The University of Adelaide Human Research Ethics Committee (HREC number H-2017-035) prior to commencement of the survey. A questionnaire comprising thirty questions [Table 1] was developed using skip logic on some questions to appropriately manage responses. The questionnaire was designed to assess the clinical practice preferences of Australian and New Zealand dentists and specialists regarding clinical decisions made in the management of patients with an edentulous mandible.
Table 1: Questionnaire formulated for survey participants (response options within parentheses)

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An initial invitation to participate was sent to all known Australian-based professional membership bodies. Based on replies, all ADA state branches, the Australian and New Zealand Association of Oral and Maxillofacial Surgeons, Australian and New Zealand Academy of Periodontists, and the Australian Prosthodontic Society were sent details of the investigation and a copy of the survey. On agreeing to participate, the membership bodies were provided with a unique survey link that directed their members to SurveyMonkey (San Mateo, CA, USA) to complete the questions online. Once a respondent had completed a survey, their responses were automatically saved to the database within SurveyMonkey for analysis. All responses were anonymous and were pooled together so as not to represent specific membership bodies. Data were collected from May 2017 to September 2017. Descriptive categorical data were presented in the form of totals and percentage values.

  Results Top

Responses were received from members of five of the ten professional organizations who initially agreed to participate. Of the five organizations involving a total of 2680 members, 197 responses were received constituting a 7.35% response rate. Not all respondents completed all questions.

A concentrated 69.5% of respondents practiced in one particular state of Australia. The profile of the respondent's year of graduation from dental training is provided in [Table 2]. Respondents included general dentists, prosthodontists, periodontists, and oral surgeons. The proportion of respondents who worked full time was 66.6% and 84.8% were predominantly in private practice. The percentage of respondents who worked in metropolitan practice was 76.2%.
Table 2: Year of respondent graduation of respondents

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The highest level of education in implant dentistry attained is summarized in [Table 3]. There were 65.5% (129 of 197) of respondents who were practicing implant dentistry and had undertaken training programs ranging from short courses such as extended training (>1 day) to accredited training programs. The aspects of implant dentistry practiced by the respondents are summarized in [Table 4].
Table 3: Respondent's highest level of education in implant dentistry and implant practicing status

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Table 4: Practice of implant dentistry

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Using skip logic, respondents who were not practicing implant dentistry did not continue further in the survey resulting in a reduced total number of responses.

Of the 36 respondents who had undertaken continuing professional development courses (≤1 day), 47.22% were involved in one or more aspects of implant dentistry for the edentulous mandible. There were no respondents involved in implant treatment of the edentulous mandible who had not received any education in implant dentistry.

Of 115 respondents, 34.8% had practiced the surgical aspect of implant dentistry for more than 10 years, whereas 39.1% did not practice the surgical aspect.

A wide range of dental implant brands were used by respondents practicing implant dentistry [Table 5] with the most popular being Straumann and Nobel Biocare.
Table 5: Brands of dental implants used by respondents (multiple response options were permitted)

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The range of clinical procedures performed for mandibular edentulous patients is provided in [Table 6]. Overall, 35.8% of 95 respondents practiced the restorative aspect of both mandibular fixed complete implant denture (MFCID) and mandibular implant overdentures (MIODs). Of 36 respondents, 55.56% had practiced the restorative aspect of implant dentistry for more than 10 years and all of the 36 respondents had received some form of implant education.
Table 6: The extent of edentulous mandible practice by respondents

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Of the respondents who chose to refer for the surgical aspect of MIOD treatment, 28.0% of 93 respondents referred to an oral surgeon and 36.6% referred to a periodontist. For MFCID treatment, 40.7% of 123 respondents referred to an oral surgeon and 25.2% referred to a periodontist. A clear majority of referrals for the restorative aspect of both implant treatment modalities were to prosthodontists (57.3% of 96 respondents and 66.3% of 101 respondents respectively).

There were 72% of 111 respondents who preferred two implants to support a MIOD and 97% of 98 respondents who preferred four or more implants for a MFCID. The reason (s) for choosing a MIOD instead of MFCID are provided in [Table 7].
Table 7: Reason(s) for choosing a mandibular implant overdenture instead of fixed complete implant denture (multiple response options were permitted)

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The use of a surgical template and/or a cone-beam scan was the preferred method of planning with 59.1% of the 120 responses received planning MFCID treatment and 59.5% of 158 responses planning MIOD treatment in this manner. The least favored approaches were leaving the planning to the surgeon or using best clinical judgment.

Conventional implant loading was preferred for both MFCID (54.3% of 92 respondents) and MIOD (79.6% of 98 respondents). Almost all respondents' preferred method of taking impressions for MFCID treatment (95.83% of 46 respondents) and MIOD (96.72% of 61 respondents) was by conventional means rather than digitally, with splinted open tray “pick-up” impressions preferred by 78.7% of 47 respondents for MFCID treatment.

The preferred methods of retention of MIODs are provided in [Table 8] with individual locator attachments being dominant. The use of any form of reinforcement to strengthen MIOD was reported as “always” or “frequent” by 39.3% of 61 respondents. Of 51 respondents, 96% preferred screw retention for MFCID treatment.
Table 8: Methods of retention for mandibular implant overdentures

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Milled titanium was the preferred frame material for definitive MFCID as shown in [Table 9] with acrylic teeth being preferred over ceramic teeth [Table 10]. There was no association between preferred frame and tooth material and year of graduation, geographical distribution, or extent of practice.
Table 9: Preferred definitive frame material for mandibular fixed complete implant dentures

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Table 10: Preferred definitive frame and tooth materials for mandibular fixed complete implant dentures

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The frequency of cases in which respondents estimated complications were observed during the normal lifespan of the prosthesis is presented for MIOD [Table 11] and MFCID [Table 12]. There were 44 (61.11%) of 72 respondents who considered patients treated with MFCID and MIOD to be equally satisfied, whereas 25 (34.72%) of 72 respondents thought patients treated with MFCID were more satisfied than patients treated with MIOD.
Table 11: Frequency of complications encountered during the normal lifespan of mandibular implant overdentures

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Table 12: Frequency of complications encountered during the normal lifespan of mandibular fixed complete implant dentures

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Respondents reported reviewing patients treated with either type of mandibular implant prosthesis at 1 week (37.68%) or 2 weeks (21.74%) after delivery. The average life span before replacement of prosthesis is summarized in [Figure 1]. The average reported lifespan of MRCDs and MIODs was 5 years and for MFCIDs was 10 years.
Figure 1: Longevity of prosthesis

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  Discussion Top

Practice of implant dentistry

The 65.5% of respondents who practiced one or more aspects of restorative and surgical implant dentistry relating to the edentulous mandible was lower than most figures from comparable studies[15],[16],[17] involving general practitioners potentially due to global predoctoral curriculum differences in Australia, United States, Canada and Hong Kong.[18],[19] It was reassuring to establish that implant treatment was provided predominantly by practitioners who had undertaken formal training such as extended training programs lasting more than 1 day, accredited specialty training programs or postgraduate diplomas or degrees. But, the debate on the level of training required for performing implant treatment will no doubt continue, with sources recommending matching the level of training combined with practitioner experience to established measures of treatment complexity.[20] The authors would like to suggest a minimal level of education required before providing restorative or surgical implant treatment that is benchmarked against case complexity.

Implant brand

In 2003, a review of scientific evidence available on different implant systems revealed that approximately 80 manufacturers marketed more than 220 different implant brands around the world.[21] While many brands have vanished from the market, only a minority of the reported brands have clinical documentation.[21] It was noteworthy that respondents in the present survey generally used implants that have been well researched.

Attachment system

In a recently published international survey of prosthodontists, separate locator attachments were found to be the predominant attachment system for MIODs,[22] which is in agreement with our findings. Individual locator attachments present advantages of a range of implant abutment alignment correction, easy maintenance, different retention strengths, and a low profile requiring low component space. However, there is no evidence that supports different attachment types influencing implant success, patient satisfaction or prosthetic maintenance requirements, and thus the choice of attachment system appears largely dictated by individual operator preference as reflected in the wide range of systems reported in our study.[23],[24],[25] While acknowledging the marketplace competition, there does appear to be a need to streamline the range of materials and attachment systems to allow for future treatment and maintenance requirements.

Frame material choices

The dominant use of milled titanium frameworks reported in our study aligns with recent worldwide popularity of this material due to ease of use and reported higher precision of fit compared with the traditional casting techniques with noble metal alloys.[26],[27] The alternative use of base metal frameworks such as cobalt chrome has the advantage of reduced cost and superior physical properties when compared with traditional noble metal alloys and was supported by the current study's findings.


In the current study, patients with removable and fixed prostheses were reported to present with a wide range of different types and frequencies of implant and prosthesis complications. This underscores the importance of educating patients of potential complications and their management strategies that may incur additional costs. In addition, a discussion of the likely future maintenance requirements adds to the patient education process that allows patients to make fully informed decisions that are financially viable both in the short and long term.

In turning to the literature to help guide such discussions, a confusing body of evidence is found due to the inconsistency in the reporting of true prosthetic complications primarily caused by the variable definitions of events, maintenance, complications, and failure. While Bryant could not calculate an overall complication incidence for implant overdentures due to a lack of similar study design that allowed simultaneous evaluation of all or most of the complications,[28] a systematic review conducted by Berglundh et al. reported higher failure rates for implant supported overdentures compared with fixed implant supported prostheses.[29]

Prosthesis longevity

Evidence on the longevity of complete dentures is lacking;[30] however, it has been reported that complete dentures can be expected to last between 5 and 10 years[31] compared with an average lifespan of MFCIDs of 6.57 ± 3.87 years,[32] which is in agreement with our study. For some patients, a discussion of the expected prosthesis lifespan in conjunction with the treatment requirements and cost–benefit considerations may influence their choice of treatment option.


Despite multiple follow-ups, some general and specialist professional organizations did not participate in the survey; therefore, the results may not be representative of the Australian practitioner population. Additionally, not all general and specialist practitioners are members of professional societies and some practitioners are members of more than one society. The number of responses varied for individual questions due to allowing multiple responses and through the use of skip logic. The survey required respondents to provide their most used technique and it is acknowledged there will likely be variations in the treatment provided for individual patients. Also, the responses were based on recollection of events and most frequent occurrences.

The relatively small sample size (and hence lack of statistical power) in the present investigation may have influenced the summary findings. In some instances, the survey link was relatively inconspicuous in the organization's periodic newsletter/member communication and may not have captured the readers' attention. Some organizational members for which the survey title was outside their usual scope of practice may not have accessed the survey at all. Respondent fatigue is also a well-documented phenomenon that may have been present in this relatively long survey,[33] but the reducing response rate throughout the survey may have been camouflaged by the more specialized nature of latter questions.

The role of self-administered questionnaires in collecting information from medical and dental professionals remains problematic with a poor response rate hindering the impact of the collected data.[34],[35] Nevertheless, electronic questionnaires are now commonly used due to their efficiency of administration, inexpensive nature, ability to reach a wide-ranging geographical region, and ease of online completion.

  Conclusions Top

The highest level of education in implant dentistry varied significantly between respondents and was potentially reflected in the wide variety of reported treatment approaches. Even within a specific implant prosthesis type, there was no universally accepted modality of management. Future research should focus on alternative survey strategies for obtaining important data representative of the total practicing population.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Sanders AE, Slade GD, Carter KD, Stewart JF. Trends in prevalence of complete tooth loss among Australians, 1979–2002. Aust N Z J Public Health 2004;28:549-54.  Back to cited text no. 1
Burt BA, Eklund SA. Dentistry, Dental Practice, and the Community. 5th ed. Philadelphia: WB Saunders Co.; 1999.  Back to cited text no. 2
Crocombe LA, Slade GD. Decline of the edentulism epidemic in Australia. Aust Dent J 2007;52:154-6.  Back to cited text no. 3
Brånemark PI, Hansson BO, Adell R, Breine U, Lindström J, Hallén O, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl 1977;16:1-32.  Back to cited text no. 4
Ekelund JA, Lindquist LW, Carlsson GE, Jemt T. Implant treatment in the edentulous mandible: A prospective study on Brånemark system implants over more than 20 years. Int J Prosthodont 2003;16:602-8.  Back to cited text no. 5
Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, et al. The McGill Consensus Statement on overdentures. Eur J Prosthodont Rest Dent 2002;10:95-6.  Back to cited text no. 6
Thomason JM, Feine J, Exley C, Moynihan P, Müller F, Naert I, et al. Mandibular two implant-supported overdentures as the first choice standard of care for edentulous patients – The York Consensus Statement. Br Dent J 2009;207:185-6.  Back to cited text no. 7
Andreiotelli M, Att W, Strub JR. Prosthodontic complications with implant overdentures: A systematic literature review. Int J Prosthodont 2010;23:195-203.  Back to cited text no. 8
Walton JN, MacEntee MI. Choosing or refusing oral implants: A prospective study of edentulous volunteers for a clinical trial. Int J Prosthodont 2005;18:483-8.  Back to cited text no. 9
MacEntee MI, Walton JN. The economics of complete dentures and implant-related services: A framework for analysis and preliminary outcomes. J Prosthet Dent 1998;79:24-30.  Back to cited text no. 10
Zitzmann NU, Sendi P, Marinello CP. An economic evaluation of implant treatment in edentulous patients-preliminary results. Int J Prosthodont 2005;18:20-7.  Back to cited text no. 11
Feine JS, Maskawi K, de Grandmont P, Donohue WB, Tanguay R, Lund JP. Within-subject comparisons of implant-supported mandibular prostheses: Evaluation of masticatory function. J Dent Res 1994;73:1646-56.  Back to cited text no. 12
Dudley J. Implants for the ageing population. Aust Dent J 2015;60 Suppl 1:28-43.  Back to cited text no. 13
Carlsson GE, Kronstrom M, de Baat C, Cune M, Davis D, Garefis P, et al. A survey of the use of mandibular implant overdentures in 10 countries. Int J Prosthodont 2004;17:211-7.  Back to cited text no. 14
Esfandiari S, Majdzadeh R, Feine J. Types of Canadian dentists who are more likely to provide dental implant treatment. Implant Dent 2011;20:76-84.  Back to cited text no. 15
Cheung M, Kao P, Lee N, Sivathasan D, Vong C, Zhu J, et al. Interest in dental implantology and preferences for implant therapy: A survey of Victorian dentists. Aust Dent J 2016;61:455-63.  Back to cited text no. 16
Murray CM, Thomson WM, Leichter JW. Dental implant use in New Zealand: A 10-year update. N Z Dent J 2016;112:49-54.  Back to cited text no. 17
Atashrazm P, Vallaie N, Rahnema R, Ansari H, Shahab MP. Worldwide predoctoral dental implant curriculum survey. J Dent (Tehran) 2011;8:12-8.  Back to cited text no. 18
Barwacz CA, Avila-Ortiz G, Allareddy V, Tamegnon M, Hoogeveen K. Comparison of Canadian and United States predoctoral dental implant education. J Can Dent Assoc 2016;82:g22.  Back to cited text no. 19
Ivanovski S, Mattheos N, Scholz S, Heitz-Mayfield L. University postgraduate training in implant dentistry for the general dental practitioner. Aust Dent J 2010;55:339-45.  Back to cited text no. 20
Jokstad A, Braegger U, Brunski JB, Carr AB, Naert I, Wennerberg A. Quality of dental implants. Int Dent J 2003;53:409-43.  Back to cited text no. 21
Kronstrom M, Carlsson GE. An international survey among prosthodontists of the use of mandibular implant-supported dental prostheses. J Prosthodont 2019;28:e622-6.  Back to cited text no. 22
Gotfredsen K, Holm B. Implant-supported mandibular overdentures retained with ball or bar attachments: A randomized prospective 5-year study. Int J Prosthodont 2000;13:125-30.  Back to cited text no. 23
Timmerman R, Stoker GT, Wismeijer D, Oosterveld P, Vermeeren JI, van Waas MA. An eight-year follow-up to a randomized clinical trial of participant satisfaction with three types of mandibular implant-retained overdentures. J Dent Res 2004;83:630-3.  Back to cited text no. 24
Carlsson GE. Implant and root supported overdentures – A literature review and some data on bone loss in edentulous jaws. J Adv Prosthodont 2014;6:245-52.  Back to cited text no. 25
Paniz G, Stellini E, Meneghello R, Cerardi A, Gobbato EA, Bressan E. The precision fit of cast and milled full-arch implant-supported restorations. Int J Oral Maxillofac Implants 2013;28:687-93.  Back to cited text no. 26
Al-Fadda SA, Zarb GA, Finer Y. A comparison of the accuracy of fit of 2 methods for fabricating implant-prosthodontic frameworks. Int J Prosthodont 2007;20:125-31.  Back to cited text no. 27
Bryant SR, MacDonald-Jankowski D, Kim K. Does the type of implant prosthesis affect outcomes for the completely edentulous arch. Int J Oral Maxillofac Implants 2007;22 Suppl:117-39.  Back to cited text no. 28
Berglundh T, Persson L, Klinge B. A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years. J Clin Periodontol 2002;29 Suppl 3:197-212.  Back to cited text no. 29
Schwass DR, Lyons KM, Purton DG. How long will it last? The expected longevity of prosthodontic and restorative treatment. N Z Dent J 2013;109:98-105.  Back to cited text no. 30
Zarb G, Bolender CL, Carlsson GE. Boucher's Prosthodontic Treatment for Edentulous Patients. 11th ed. St Louis: Mosby; 1997.  Back to cited text no. 31
Attard NJ, Zarb GA. Long-term treatment outcomes in edentulous patients with implant-fixed prostheses: The Toronto study. Int J Prosthodont 2004;17:417-24.  Back to cited text no. 32
Ben-Nun P. Respondent fatigue. Encyclopedia Survey Res Methods 2008;2:742-3.  Back to cited text no. 33
Cartwright A. Professionals as responders: Variations in and effects of response rates to questionnaires, 1961-77. Br Med J 1978;2:1419-21.  Back to cited text no. 34
Guo YN, Dudley J, Richards LC, Logan RM. Implant dentistry in Australia: The present and future. A survey of Australian dentists and specialists. Aust Dent J 2017;62:500-9.  Back to cited text no. 35


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12]


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