DENTAL IMPLANT TREATMENT AT A NIGERIAN TEACHING HOSPITAL

Abstract

Background

There has been an increase in the awareness of dental implant as a replacement option for missing teeth and this has consequently led to an increased demand for dental implant.

Aim & Objectives

To determine the distribution and pattern of implant placement in a tertiary hospital in a developing country.

Materials & Methods:

This retrospective study was conducted at the University College Hospital to assess the treatment outcome of all the patients who had had osseointegrated root form endosseous dental implants over a period of five years. The data obtained included age, gender, socioeconomic status (SES), medical history, reason for implant placement, number of implants per patient, distribution of missing teeth, complications and treatment outcome. The data were analyzed for percentages, means, SD and presented in tables and figures.

Results

Forty two implants (40 conventional & 2 immediate) were placed in the 23 patients (M-15, F=8).There were 15(65.2%) males and 8(34.8%) females. Pre-implant placement ridge augmentation was done in 3(7.1%) patients while 9 (39.1%) patients had augmentation during implant placement surgery. Left maxillary central incisor was the most commonly replaced tooth in 31% followed by the right maxillary central incisor in 19%. The success rates in the study at 1 year and 5 years were 97.4% and 95.2% respectively.

Conclusion

A high success rate (95.2%) of implant therapy at 5 years recorded in this study compared favorably with what is obtainable in many other countries of the world.

Introduction

Treatment with dental implants is one of the procedures available to help the partially dentate or totally edentulous individuals. Dental implants can be used to stabilize both removable and fixed prostheses. Recently, the use of dental implants in restorative dentistry has been increasing1. This trend may be due partly to a high level of awareness of implant as an option for replacing missing teeth2^-5. In the previous studies2^-5, the level of awareness ranged from 66.4% to 77%, while in Nigeria, the level of awareness was 22.6%6 and 7.2%7among patients and health workers respectively. However, the clinical success of dental implant therapy has improved significantly for the majority of the population in the United States of America such that some clinicians consider it to be a form of standard of care8.

The outcomes of implants placed by specialists in academic setting and those placed in private general dental practices have been systematically reviewed. Iqbal and Kim9 conducted a systematic review and meta-analysis of 34 implants outcome studies and reported a 3-5 year success rates in excess of 95% for single unit implants, while a 97% success rate was also reported for another systematic review and meta analysis of 46 reports at 4-6 years follow up10.

A retrospective study11 of 922 implants placed by general dental practitioners from 87 practices in 25 states of the USA reported a lower success rate of 93%. In the review, the mean age of participants (M=396, F=526) was 61.4 ± 12.2 years and the commonest reason for implant placement was fractured tooth (32.6%), followed by endodontic failure (25.1%). Implants were most frequently placed in mandibular molar region (30.1%) followed by maxillary premolar area (21.2%).

In Nigeria, a retrospective review 12of implant replacement of missing teeth over a period of 6yrs at a private dental clinic revealed a success rate of 96% in 227 implants placed in 121 patients (M=68, F=53) with the highest number of implant placed in the molar region.

The paucity of studies or reports on implant placement in our environment as a whole, and the necessity to contribute to the literature necessitated the conduct of this study.

Patients & Methods:

This was a retrospective study of the outcome of all the patients who had had dental implant placed using osseointegrated root form endosseus dental implants (Bicon, Boston, MA) from July 2008 to July 2013 at the Implantology Centre, University College Hospital, Ibadan, Nigeria.

The centre is a specialist referral –based clinic established by the University of Ibadan and the University College Hospital Ibadan. The patients in this unit were seen and treated following established protocol for implant placement by the consultants that make up the Implantology team which comprised of the Oral & maxillofacial surgeons, the restorative dentists and a periodontologist. The screening of the patients were done collectively by the above mentioned specialists, based on the general principles of appropriate case selection following preliminary guidelines for placement of endoddeous dental implants13. All the patients in this study were treated under local anaesthesia.

The information obtained from the records for this study were age, gender, socioeconomic status (SES), medical history, reason for implant placement, number of implants per patient, distribution of missing teeth, complications and treatment outcome. Patients that were treated with another implant system were excluded from the study. The data were analyzed using percentages, means, SD and presented in tables and figures.

Measures of implant success in this study were as defined by Albrektsson and colleagues14 which included absence of pain on percussion, no mobility, functional implant, absence of clinical/radiological evidence of peri-implantitis, no excessive crestal bone loss .

Ethical clearance for the study was obtained from the Institution Ethical Review Committee of the University of Ibadan/University College Hospital Ibadan, Nigeria.

Results

Table 1 shows the demographic characteristics of patients treated with endosseous implants at Ibadan, Nigeria (2008-2013). A total of 23 patients made up of 15(65.2%) males and 8(34.8%) females were treated during the study period. Their age range was 18-78 years with a mean of 48.4 ±16.6 years. The majority (56.5%) were in the high socio-economic class (SEC). Fifteen out of 23 (65.2%) had no history of any systemic disease. Those that had hypertension with or without Diabetic Mellitus (DM)/others were controlled with medication. One patient had Haemoglobin SS (HbSS) as shown in Table 1.There was no history of smoking/bruxism among the patient treated. The most common reason for implant placement was tooth loss following trauma in 39.13% of patients (figure 1), while the most predominantly seen presentation was Kennedy Class III (figure 2). Forty two implants (40 conventional & 2 immediate) were placed in the 23 patients. However, 2 (4.8%) of the implants placed failed and these were in a patient with diabetes mellitus and the other was a sickler (HbSS). The majority (47.8%) had one implant each, followed by 43.5% that had 2 implants each as shown in figure 3.

Table 1. Sociodemographic characteristics of the Patients.

Variables	Values
No of Patients	23
Age Range	18 – 78 years
Mean Age	48.4 ± 16.6 years
Gender	N	%
Male	15	65.2
Female	8	34.8
Total	23	100
Educational Level
Postgraduate	11	47.8
University/HND	12	52.2
Total	23	100.0
Socio-economic Status
High	13	56.5
Middle High	10	43.5
Total	23	100.0
Medical History (presence of some systemic diseases)
	Present	Absent
Hypertension	2	-
Hypertension & DM	1	-
Sickle Cell Disease	1	-
Diabetics Mellitus	2	-
Asthma	1	-
Asthma & Hypertension	1	-
Total	8	15

Figure 1 . Reasons for implant placement .

Figure 2 . Distribution of Edentulous spaces .

Figure 3 . No of implant placed per patient .

Pre-implant placement ridge augmentation was done in 3 patients while 9 (39.1%) patients had augmentation during implant placement surgery. Left maxillary central incisor was the most commonly replaced tooth (31%) followed by the right maxillary central incisor in 19% (Table 2).

Table 2. Missing teeth replaced with implants per quadrant.

Upper Right Quadrant			Upper Left Quadrant			Lower Left Quadrant			Lower Right Quadrant
	N	(%)		N	(%)		N	(%)		N	(%)
11	8	19.0	21	13	30.9	31	1	2.4	43	3	7.1
12	1	2.4	22	1	2.4	36	2	4.7	44	1	2.4
13	1	2.4	26	1	2.4	37	1	2.4	46	3	7.1
14	1	2.4	27	1	2.4				47	1	2.4
15	1	2.4
16	2	4.8
Total 14			16			4			8

The success rate in the study at 1 year follow-up was 97.4% while at 5 years it was 95.2%, .Most patients came for the one day and one week post-operative reviews. The most recorded complications post treatment were gross post-operative swelling in 34% and dislodged abutment in 33% as shown in figure 4.

Figure 4 . Complications of implant placement .

Discussion

Implant therapy has become accepted as a predictable treatment option for the replacement of missing teeth. The 23 patients studied were followed up for a period of 1-5 years with a success/survival rate of 95.2%. This is slightly lower than the result obtained in a private general dental practice (GDP)12 but higher than the systematic review done abroad11. The low number of patients treated over this long period may be attributed to the high cost of implant therapy which may not be affordable by many people living in Ibadan, unlike the more economically buoyant Lagos 12.

The number of males treated in our centre was almost double that of females. This is similar to what was previously reported in a Nigerian study unlike in the systematic review by Da Silva et al 11where more females were treated. Men are more likely to be financially more buoyant and better able to afford implant placement and thus account for why there were more males than females

The reasons for implant placement as recorded in this study are in agreement with a previous study11. This may further explain the reason why more teeth were replaced in the anterior region than the molar in the study. The majority of implants were used to replace the left maxillary central incisor. This is in agreement with previous studies15^-17 that reported the highest prevalence of trauma to this tooth type.

Though the two failed implants were recorded in patients with chronic diseases that may appear to be risk factors in implant failure, the poor quality and quantity of bone (type IV) in the two cases significantly increased the risk of failure as detected during pre-surgical evaluation and surgical placement of the implants since all the implants were placed by the authors. Studies18^-20 have shown that implants placed in type IV quality bone are at an increased risk of failure. Apart from the two implants that had to be removed, all the reported complications in this study were appropriately treated and remain functional till date.

Conclusions

The success of implant therapy in this environment compared favourably with the outcome elsewhere, even though the cost of treatment is still unaffordable to a large number of Nigerians.