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Authors: Dr. Arjun Jawahar Sharma, Dr. Rahul Nagrath

INTRODUCTION

India is in a phase of demographic transition. The rate of edentulousness differs much between countries and it has declined dramatically during the last few decades in most of the countries. As per the 1991 census, the population of the elderly in India was 57 million as compared with 20 million in 1951. There has been a sharp increase in the number of elderly persons and India is today home to 100 million senior citizens. It has been projected that by the year 2050, the number of elderly people would rise to about 324 million.1 India has thus acquired the label of “an ageing nation” with 7.7% of its population being more than 60 years old. Oral health related problems in elderly is the biggest factor leading to edentulism.Factors associated with edentulism include socioeconomic factors such as increasing age, being female, lower education, lower economic status, lower social class, health security, and rural residence; chronic conditions such as asthma, diabetes, arthritis , angina pectoris, stroke, hypertension and obesity; health risk behaviour including smoking, inadequate consumption of fruit and vegetables and infrequent dental visitsand other health-related factors, including functional disability, lower scores on cognitive testing , poorer self-rated level of general health, social cohesion and self-esteem and oral health related-quality of life.2

Until the introduction of osseointegrated implant-supported prostheses, complete dentures were the only available treatment for edentulous patients. The edentulous people in the world belong to the poorest section of the population and implant treatment is unrealistic for them; for many even “lowtech” therapies like conventional dentures are beyond their reach.3 However, in the mid 1980’s treatments with mandibular implant overdentures were introduced.4 Being less expensive and less complicated but yet successful, mandibular implant overdentures soon became popular worldwide.Maxillary implant overdentures on few implants have in general been found less successful than the mandibular two implant over denture.5,6

The aim of this article to present a literature review on implant overdentures and a step by step pictorial procedure of two implant supported overdenture.

MANDIBULAR IMPLANT OVERDENTURES

Several randomized control trials have demonstrated that implant overdentures provide patients with better outcomes than do conventional dentures. Overdentures plays a very vital role in improving the oral fuction i.e chewing efficiency, masticatory force and general satisfaction in edentulous patients. Studies have proven that overdentures have better chewing efficiency by more than half of the particle size chewed with twice the masticatory force and high patient satisfaction levels as compared with the conventional dentures.The McGill & New York consensus states that mandibular twoimplant overdentures are the gold standard for edentulous patient. Looking at the global scenario and with the demographic transition of geriatric patients in india, the dental fraternity of india should consider the overdentures as the first choice of treatment for edentulous patients.This is a tempting possibility but it has been criticized as unrealistic, mainly because of the fact that the edentulous patients are poor and cannot afford any implant treatment.4 It should also be remembered that the majority of complete denture wearers are quite satisfied with their predicament, both functionally and esthetically.

Retention system for implant overdentures

The retention systems for the two- implant overdenture scan be divided into splinted and unsplinted ones. The splinted systems use an interconnecting bar and a retentive clip; for the unsplinted implants there are several retention types available such as ball attachments, magnets and locators.There is no strong evidence for the superiority of one system over the others regarding patient satisfaction, survival, peri implant bone loss and relevant clinical factors.However, irrespective of the differences between the retention systems, mandibular implant overdentures provide increased patient comfort and acceptance as well as oral function compared to complete dentures.

Early loading

Early loading of mandibular implant overdentures at 6 weeks or even 2 weeks has been shown to be an effective treatment. Loading can be minimized

by requesting the patients to eat only soft meals for the first few weeks.6 Based on recent studies it has been concluded that early loading protocols produce equal outcomes as conventional loading and thus is a viable option in construction of mandibular overdentures.7,8 However, a recent systematic review concluded that although all three loading protocols (immediate, early and conventional loading) provide high survival rates, early and conventional loading protocols are still better documented than immediate loading and seem to result in fewer implant failures during the first year.8

Cost of treatment of edentulous jaws

When comparing the cost of different treatment options it is clear that the cheapest alternative is the conventional complete denture followed by the implant overdenture; a fixed implant-supported prosthesis is the most expensive. Economical aspects on prosthodontic treatment are rare but a few studies deserve to be mentioned. Long term comparisons (over 9 and 15 years) have demonstrated that overdentures are a more cost-effective treatment compared to fixed prostheses.9 In a comparison of different types of overdentures it was shown that a construction using 4-implants was more expensive than one with 2 implants but required less aftercare over 8 years. Nevertheless, the authors concluded that the 2-implant bar-retained overdenture was most effective when considering other factors such as patient satisfaction, clinical implant performance and costeffectiveness.10

MAXILLARY IMPLANT OVERDENTURE

Implant overdentures in the maxilla have in general not been as successful as in the mandible, but the early poor results were probably partly due to the fact that maxillary implant overdentures often were made as a “rescue treatment” when a fixed prosthesis had failed. The results improved when maxillary implant overdentures were made as a planned treatment following strict protocols. Nevertheless it is evident that maxillary implant overdenturespresent a number of different challenges compared to the predictable benefits of mandibular 2-implant overdentures.11,12 Systematic reviews concluded that maxillary overdentureson 4 or more implants in a splinted construction provided high survival (> 95% for the first year) both for implants and overdenture.Using four or less implants and a ball attachment system is in general less successful than four or more implants with splinted bar attachments.12

Fig.1Maxillary Overdenture Splinted bar attachment
  SINGLE MIDLINE IMPLANT

To reduce the cost of treatment a single midline implant has been tried to retain a mandibular implant overdenture(Fig. 3). An early 5-year study demonstrated good results with such an overdenture. These and similar results 41 ledto a suggestion to use the single midline implant overdentureas an inexpensive treatment for geriatric and other patients with low functional demands.13 During the last few years several short-term randomized clinical trials have been presented indicating an increased interest in the profession to evaluate this option. The results of these short-term studies have in general been assessed as promising but long-term observations are required for a firm conclusion regarding the clinical usefulness of mandibular overdentures supported by a single midline implant.14,15

image
Fig. 2 & 3 Single Midline Implant
IMPLANT OVERDENTURE VS FIXED IMPLANT– SUPPORTED PROSTHESIS

Many factors influence the choice between a fixed and removable implant prosthesis in treatment of an edentulous patient. At the introduction of osseointegrated implants in Sweden in the 1970s, professor Brånemark suggested fixed prostheses as the first choice.There is no current data published but it would be interesting to see the recent development internationally concerning the choice between overdenture or fixed prosthesis in implant treatment of the edentulous mandible.

DISCUSSION

There is overwhelming evidence that implant overdenturesare superior to conventional complete dentures in several aspects, especially for the edentulous mandible. It has therefore been suggested that, if possible, mandibular implant overdentures should be the first option for complete denture wearers with adaptation difficulties.16,17 Even if the prevalence of edentulism is decreasing in most countries there is still a great number of edentulous individuals needing treatment. A majority of them belong to the poorest segment of the population and cannot afford implant treatment; they will have to rely on complete dentures. For complete denture wearers with adaptation difficulties the mandibular denture is usually the most critical problem. Treating such patients with a fixed implant-supported prosthesis in the mandible but keeping the maxillary complete denture led to dramatic improvement of oral functions and “oral well-being” both in short- and longterm perspectives.18 The great functional improvement provided by a mandibular implant overdenture together with a maxillary complete denture is well established. A mandibular two-implant overdenture is less expensive than a fixed implant-supported prosthesis and can therefor makeimplant treatment available to more edentulous patients.

Another way to further reduce the cost of implant treatment and expand the benefits of it to more people is by using a single midline implant as support for a mandibular overdenture. This is a promising option according to short term studies but awaiting long-term evaluation.19 The stable and successful long-term results for two- implant overdentures in the mandible cannot be transferred to the maxilla. A maxillary implant overdenture needs more support, preferably 4 to 6 implants splinted with a bar, to reach similar results as a two-implant option in the mandible.20

IMPLANT OVERDENTURE MADE EASY : STEP BY STEP PROCEDURE
Case 1
Fig. 1 Edentulous Mandible arch
Fig. 1 Edentulous Mandible arch Fig.2 Crestal Incision
 
Fig.3 Placement of Surgical Stent Fig.4Lanc Pilot Drill along with surgical stent
 
Fig.5 Osteotomy sites at B&D region. Fig.6 Placement of Implants with cover screws.
Fig.7 Interrupted Sutures Placed.
 
Fig.8 Installation of ball attachmentsh Fig.9 Placement of separator
Fig.10 Placement of metal housings Fig.11 Markings with eugenol paste on metal housing
 
Fig.12 Space created for metalhousing Fig.13 Relief holes for excess acrylic resin
 
Fig.14 &15 Mandibular implant retained overdenture and maxillay complete denture intraorally and extraorally.
 
Fig.16&17 Right and Left Lateral view.
 
Case 2
Fig.1 Maxillary Arch Fig.2 Mandibular Arch
 
Fig.3 Radiographic assesment
 
Fig.4 Mid Crestal Incision Fig.5 Elevation of the mucoperiosteal flap
 
Fig.6 Bone Exposed at canine region (B&D) Fig.7 Osteotomy Prepared i.r.t 33
 
Fig.8 Implant Placement and tighten at 35N/cm Fig.9 Implant Placed
 
Fig.10 Cover screw placed Fig.11 Implant placed i.r.t 43 region
 
Fig.12 Cover screw placed i.r.t 43 region. Fig.13 Plasma rich fibrin
 
Fig.14 Plasma Rich fibrin placed. Fig.15 Interrupted Sutures Placed.
 
Fig.16 Ball and Socket attachment Fig.17. Metal Housings with nylon caps.
 
Fig.18 Intaglio surface of the denture Fig.19 Maxillary and mandibular overdenture in occlusion.
CONCLUSION

In edentulous mandibles two-implant overdentures provide excellent longterm success and survival, including patient satisfaction, improved oral functions and oral health related quality of life. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla overdentures need to be supported on more than two implants; 4 to 6 implants splinted with a bar have demonstrated good functional results.

REFERENCES
  1. Age care statistics. [cited on 2017 July]. Available from: http://www.helpageindia.com.
  2. Ingle GK, Nath A. Geriatric Health in India: Concerns and Solutions. Indian Journal of Community Medicine : Official Publication of Indian Association of Preventive & Social Medicine. 2008;33(4):214-218.
  3. Carlsson GE, Omar R. The future of complete dentures inoral rehabilitation. A critical review. J Oral Rehabil 2010;37:143-56.
  4. Brånemark PI, Hansson BO, Adell R, Breine U, Lindström J,Hallén O, Ohman A. Osseointegrated implants in the treatmentof the edentulous jaw. Experience from a 10-year period.Scand J PlastReconstrSurgSuppl 1977;16:1-132.
  5. Mericske-Stern R. Prosthodontic management of maxillaryand mandibular overdentures. In: Feine JS, Carlsson GE, eds.Implant overdentures. The standard of care for edentulouspatients. Chicago; Quintessence; 2003. p. 83-98.
  6. Feine JS, Carlsson GE, eds. Implant overdentures. The standardof care for edentulous patients. Chicago; Quintessence;2003.
  7. Rutkunas V, Mizutani H, Puriene A. Conventional and earlyloading of two-implant supported mandibular overdentures.A systematic review. Stomatologija 2008;10:51-61.
  8. Schimmel M, Srinivasan M, Herrmann FR, Müller F. Loadingprotocols for implant-supported overdentures in the edentulousjaw: a systematic review and meta-analysis. Int J OralMaxillofac Implants 2014;29:271-86.
  9. Attard NJ, Zarb GA, Laporte A. Long-term treatment costsassociated with implant-supported mandibular prostheses inedentulous patients. Int J Prosthodont 2005;18:117-23.
  10. Wismeijer D, Stoker GT. Caomparison of treatment strategiesfor implant overdentures. In: Feine JS, Carlsson GE, eds.Implant overdentures. The standard of care for edentulouspatients. Chicago; Quintessence; 2003. p. 61-70.
  11. Roccuzzo M, Bonino F, Gaudioso L, Zwahlen M, Meijer HJ.What is the optimal number of implants for removable reconstructions?A systematic review on implant-supportedoverdentures. Clin Oral Implants Res 2012;23:229-37.
  12. Osman RB, Payne AG, Ma S. Prosthodontic maintenance of maxillary implant overdentures: a systematic literature review.Int J Prosthodont 2012;25:381-91.
  13. Cordioli G, Majzoub Z, Castagna S. Mandibular overdenturesanchored to single implants: a five-year prospective study. JProsthet Dent 1997;78:159-65.
  14. Krennmair G, Ulm C. The symphyseal single-tooth implantfor anchorage of a mandibular complete denture in geriatricpatients: a clinical report. Int J Oral Maxillofac Implants2001;16:98-104.
  15. Walton JN, Glick N, Macentee MI. A randomized clinical trial comparing patient satisfaction and prosthetic outcomeswith mandibular overdentures retained by one or two implants.Int J Prosthodont 2009;22:331-9.
  16. Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ,Gizani S, Head T, Lund JP, MacEntee M, Mericske-Stern R,Mojon P, Morais J, Naert I, Payne AG, Penrod J, Stoker GTJr, Tawse-Smith A, Taylor TD, Thomason JM, ThomsonWM, Wismeijer D. The McGill Consensus Statement onOverdentures. Montreal, Quebec, Canada. May 24-25, 2002.Int J Prosthodont 2002;15:413-4.
  17. Thomason JM, Kelly SA, Bendkowski A, Ellis JS. Two implantretained overdentures-a review of the literature supportingthe McGill and York consensus statements. J Dent2012;40:22-34.
  18. Lindquist LW, Carlsson GE. Long-term effects on chewingwith mandibular fixed prostheses on osseointegrated implants.ActaOdontolScand 1985;43:39-45.
  19. Kronstrom M, Davis B, Loney R, Gerrow J, Hollender L. Aprospective randomized study on the immediate loading ofmandibular overdentures supported by one or two implants;a 3 year follow-up report. Clin Implant Dent Relat Res 2014;16:323-9.
  20. Alsabeeha NH, Payne AG, De Silva RK, Thomson WM.Mandibular single-implant overdentures: preliminary resultsof a randomised-control trial on early loading with differentimplant diameters and attachment systems. Clin OralImplants Res 2011;22:330-7.

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