Comparison of Bone Healing in Immediate Implant Placement versus Delayed Implant Placement

Abstract

Introduction:

Today, modern surgical and regenerative techniques with implant immediately placed into the prepared socket, predictable gap repair with bone substitutes and soft tissue grafts, have helped to eliminate concerns about bone deficiencies and allowed implant placement according to prosthodontic needs.

Materials and Methods:

The present in vivo study was designed to evaluate and compare the implant healing after immediate implant placement with or without bone graft and implant healing after delayed implant placement with or without bone graft. Crestal bone levels were compared in both the groups at preoperatively and postoperatively on immediate postoperatively, at 3^rd month, and at 6^th month.

Results:

Immediate implant group has more crestal bone level reduction at 3^rd and 6^th months as compared to the delayed implant group. Immediate implant with bone graft group has insignificant crestal bone level reduction at 3^rd and 6^th months as compared to immediate implant without bone graft group. Delayed implant with bone graft group has insignificant crestal bone level reduction at 3^rd and 6^th months as compared to delayed implant without bone graft group.

Conclusion:

It was concluded from this study that clinical and radiographical bone healing in the delayed implant group with or without bone graft (Group Y) appears to be better than the immediate dental implant group with or without bone graft (Group X).

INTRODUCTION

In an exciting age of transformative clinical transition, the advent of osseointegrated implants in dentistry represents a turning point. Endosseous dental implant therapies have increasingly become the prosthetic standard of treatment for a wide variety of clinical applications due to their various therapeutic options and high predictability of success.[1]

Osseointegration is important for a successful outcome of dental implantation.[2] Several variables, including placement time (immediate/delayed), implant geometry, accessible bone condition, etc., have been described as critical for achieving osseointegration.[3] In response to an increased demand for a shorter treatment plan, different surgical positioning and loading protocols have been developed. To describe the time of implant placement, different terminologies are used, such as immediate placement, early placement, or traditional delayed placement.[2,3]

Delayed implant placement is a conventional technique with the advantage of less microbial infection after implant placement. Delayed implant placement plays a vital role as the environment is more conductive to healing and development of adequate osseointegration.[4,5]

Duration of recovery is traditionally accompanied by the insertion of an implant when a tooth is removed.[6] In the last two decades, by reducing the time between implant placement and implant loading, the original treatment protocol of a waiting period of 12 months or longer to enable complete socket healing was questioned.[7]

Since simpler surgical procedures and low treatment costs are preferable for the patient, it is desirable to assess the need for different bone-reconstructive therapy techniques to achieve immediate implant osseointegration. Therefore, the form and size of peri-implant bone defects that spontaneously heal with the bone must be established. The aim of the present study was to compare bone healing and crestal bone changes following the immediate versus delayed implant placement.

MATERIALS AND METHODS

Study design and procedure

Patient selection

Subjects were recruited from patients requiring placement of implant immediately after extraction and delayed implant placement in partially or complete edentulous region in the Department of Oral and Maxillofacial Surgery, Surendera Dental College and Research Institute.

An initial evaluation was conducted to determine whether the patient met with the study inclusion and exclusion criteria.

Inclusion criteria

1. Age: 19–70 years

2. Criteria for selection:

   • The patient who have complete their facial growth and teeth eruption

   • Patients who are willing with consent, motivated, and hygiene conscious

   • Patient with adequate (sufficient) amount of bone quantity and quality as determined by radiograph and clinical inspection

   • Patient without any illness or deformity that might interfere with osseointegration of the implant.

Exclusion criteria

Patients with the following systemic and local conditions were deemed ineligible.

Study design

The study was designed as a randomized controlled trial. The subjects requiring placement of implant immediately after extraction and delayed implant placement in edentulous areas were randomly assigned to either one of the following groups.

• Group X: Patients of immediate implant placement with or without bone graft. It further subdivided into:

  • Group A – Immediate implant placement with bone graft

  • Group B – Immediate implant placement without bone graft.

• Group Y: Patients of delayed implant placement with or without bone graft. It further subdivided into:

  • Group C – Delayed implant placement with bone graft

  • Group D – Delayed implant placement without bone graft.

Sixty patients who were in need of functional and esthetic rehabilitation because of decayed teeth or unrestorable teeth and partially edentulous patients were included in the study. Preoperatively, radiographic evaluation was done with orthopantogram and intra oral periapical radiograph.

RESULTS AND DISCUSSION

Out of 60 patients, 17 were male (57%) and 13 were female (43%) in Group X and 16 male (53%) and 14 females (47%) in Group Y.

Much has changed since the beginning of modern dentistry in the late 1700s, and rapid development has occurred since its beginning about three decades ago with respect to modern implant dentistry. Smooth surface titanium was designed for the first root type of endosseous implants and early protocols allowed two-stage surgery with the implant submerged during osseointegration, then exposed and subsequently restored.

With the development of sophisticated implant designs, treatment protocols which have developed include (Esposito et al.):

1. Immediate (placed during the same surgical intervention as the dental extraction)

2. Early implant placement (implants placed during the early stages of healing from 4 to 8 weeks)

3. Delayed (when implants are placed when the ridge has healed from 3 to 6 months).[8]

Immediate insertion of dental implants after a tooth extraction is an appealing choice with many benefits, such as minimizing postextraction resorption, optimum implant positioning, and reducing the time needed for prosthetic rehabilitation.[9,10]

In the present study, radiographs were evaluated for crestal bone level with worst values preoperatively, immediate postoperatively, at 3 months, and at 6 months with the standardization done in Adobe Photoshop CS3 and the results in Table 1 showed mean at baseline 0.014 ± 0.005 (in Group X) and 0.010 ± 0.004 mm (in Group Y) (P < 0.0001). [Figures 1–3] Mean at immediate postoperatively was 0.015 ± 0.005 (Group X) and 0.011 ± 0.004 (Group Y) (P < 0.0001). Mean at 3 months was 0.019 ± 0.005 (Group X) and 0.010 ± 0.005 (Group Y) (P < 0.0001). Mean at 6 months was 0.014 ± 0.005 (Group X) and 0.005 ± 0.004 (Group Y) (P < 0.0001). This difference was statistically significant.

Table 1.

Comparison of crestal bone levels between Group X and Group Y

Time	Groups	Crestal bone level
		Mean±SD	t	P
Preoperatively	Group X	0.014±0.005	4.975	<0.0001**
	Group Y	0.010±0.004
Immediate postoperatively	Group X	0.015±0.005	4.586	<0.0001**
	Group Y	0.011±0.004
3 months	Group X	0.019±0.005	6.825	<0.0001**
	Group Y	0.010±0.005
6 months	Group X	0.014±0.005	7.120	<0.0001**
	Group Y	0.005±0.004

SD: Standard deviation

Figure 1.

Immediate post op

Figure 3.

6 months post op

Figure 2.

3 months post op

Becker et al.[11] examined peri-implant bone defect changes at immediate and delayed implant sites after healing and found that VH 5.5 decreased to 0.5 mm and HD 3.7 mm to 0.2 mm (slightly less gain when buccal dehiscence present).

Vandeweghe et al.[12] examined that the peri-implant bone level was measured on a periapical radiograph and a mean bone loss of 0.38 mm SD 0.48 was reported (range: 0.50–1.95 mm).

Although the immediate placing of the implant is a very secure and predictable process, it is very difficult to choose an implant that corresponds precisely to the dimensions of the socket removed. The horizontal defect dimensions (HDDs) or so-called “jumping gap” must be filled with a graft material for primary stability and enhanced osseointegration despite advancements in design technologies and clinical expertise.

Schropp et al.[7] tested bone healing and crestal bone changes in dental implants that were immediate and delayed and they obtained statistically relevant differences.

In Table 2, crestal bone level was compared between immediate implant placement with bone graft and immediate implant placement without bone graft and the results showed mean at baseline 0.015 ± 0.006 in Group A (immediate implant with bone graft) and 0.013 ± 0.005 mm in Group B (immediate implant without bone graft) (P = 0.3376). Mean at immediate postoperatively was 0.016 ± 0.006 (Group A) and 0.014 ± 0.005 (Group B) (P = 0.292). Mean at 3 months was 0.019 ± 0.005 (Group A) and 0.018 ± 0.004 (Group B) (P = 0.4492). Mean at 6 months was 0.015 ± 0.005 (Group A) and 0.014 ± 0.006 (Group B) (P = 0.7704). This difference was statistically insignificant.

Table 2.

Comparison of crestal bone levels between Group A and Group B

Time	Groups	Crestal bone level
		Mean±SD	t	P
Preoperatively	Group A	0.015±0.006	0.9757	0.3376
	Group B	0.013±0.005
Immediate postoperatively	Group A	0.016±0.006	1.0739	0.292
	Group B	0.014±0.005
3 months	Group A	0.019±0.005	0.7674	0.4492
	Group B	0.018±0.004
6 months	Group A	0.015±0.005	0.2947	0.7704
	Group B	0.014±0.006

SD: Standard deviation

In Table 3, comparison between delayed implant with bone graft (Group C) and delayed implant without bone graft for crestal bone level (Group D) showed mean at baseline 0.011 ± 0.004 in Group C (delayed implant with bone graft) and 0.008 ± 0.003 mm in Group D (delayed implant without bone graft) (P = 0.3376). Mean at immediate postoperatively was 0.012 ± 0.004 (Group C) and 0.010 ± 0.004 (Group D) (P = 0.292). Mean at 3 months was 0.011 ± 0.005 (Group C) and 0.009 ± 0.005 (Group D) (P = 0.4492). Mean at 6 months was 0.005 ± 0.004 (Group C) and 0.005 ± 0.004 (Group D) (P = 0.7704). This difference was statistically insignificant. In both the groups, the effect of hydroxyapatite crystals was evaluated on the reduction of VDH, HDD, and HDW, and the results showed that a statistically insignificant difference was evident.

Table 3.

Comparison of crestal bone levels between Group C and Group D

Time	Groups	Crestal bone level
		Mean±SD	t	P
Preoperatively	Group C	0.011±0.004	0.976	0.3376*
	Group D	0.008±0.003
Immediate postoperatively	Group C	0.012±0.004	1.074	0.292*
	Group D	0.010±0.004
3 months	Group C	0.011±0.005	0.767	0.4492*
	Group D	0.009±0.005
6 months	Group C	0.005±0.004	0.295	0.7704*
	Group D	0.005±0.004

SD: Standard deviation

This is at odds with the study done by Hammerle and Lang (2001)[13] who found a statistically significant reduction in VDH, HDD, and HDW with the use of hydroxyapatite crystals which strongly suggest the use of bone graft. Peri-implant defects associated with immediate and delayed implants have a high potential for bone regeneration. At sites with HDs of 2 mm or less, spontaneous bone regeneration and osseointegration may be expected when implants with a rough surface are used. At sites with HDs >2 mm, or where one or more walls of the socket are missing, concomitant augmentation procedures with combinations of barrier membranes and bone grafts are required.

In Table 4, comparison between immediate implant with bone graft (Group A) and delayed implant with bone graft (Group C) for crestal bone level showed mean at baseline 0.015 ± 0.006 in Group A (immediate implant with bone graft) and 0.011 ± 0.004 mm in Group C (delayed implant with bone graft) (P = 0.0059). Mean at immediate postoperatively was 0.016 ± 0.006 (Group A) and 0.012 ± 0.004 (Group C) (P = 0.0048). Mean at 3 months was 0.019 ± 0.005 (Group A) and 0.011 ± 0.005 (Group C) {P = 0.001}. Mean at 6 months was 0.015 ± 0.005 (Group A) and 0.005 ± 0.004 (Group D) {P = 0.001}. This difference was statistically significant at baseline, immediate postoperatively, 3^rd month, and 6^th month. This is in accordance with studies done by Goldstein (2002)[14] who evaluated the role of use of bone graft on crestal bone level and found a statistically significant difference and strongly suggest the use of bone graft.

Table 4.

Comparison of crestal bone levels between Group A and Group C

Time	Groups	Crestal bone level
		Mean±SD	t	P
Preoperatively	Group A	0.015±0.006	2.978	0.0059**
	Group C	0.011±0.004
Immediate postoperatively	Group A	0.016±0.006	3.06	0.0048**
	Group C	0.012±0.004
3 months	Group A	0.019±0.005	4.4874	0.001**
	Group C	0.011±0.005
6 months	Group A	0.015±0.005	60.5	0.001**
	Group C	0.005±0.004

SD: Standard deviation

In Table 5, comparison between immediate implant without bone graft (Group B) and delayed implant without bone graft (Group D) for crestal bone level showed mean at baseline 0.013 ± 0.005 in Group B (immediate implant without bone graft) and 0.008 ± 0.003 mm in Group D (delayed implant without bone graft) (P = 0.0025). Mean at immediate postoperatively was 0.014 ± 0.005 (Group B) and 0.010 ± 0.004 (Group D) (P = 0.0031). Mean at 3 months was 0.018 ± 0.004 (Group B) and 0.009 ± 0.005 (Group D) (P = 0.0001). Mean at 6 months was 0.014 ± 0.006 (Group B) and 0.005 ± 0.004 (Group D) (P = 0.0001). This difference was statistically significant at baseline, immediate postoperatively, 3^rd month, and 6^th month.

Table 5.

Comparison of crestal bone levels between Group B and Group D

Time	Groups	Crestal bone level
		Mean±SD	t	P
Preoperatively	Group B	0.013±0.005	3.321	0.0025**
	Group D	0.008±0.003
Immediate postoperatively	Group B	0.014±0.005	3.236	0.0031**
	Group D	0.010±0.004
3 months	Group B	0.018±0.004	5.270	0.0001**
	Group D	0.009±0.005
6 months	Group B	0.014±0.006	4.840	0.0001**
	Group D	0.005±0.004

SD: Standard deviation

Early osteoid formation starts after 7 days in an undisturbed extraction socket, mineralization begins at 21 days and is well advanced at 6 weeks, so it would be rational to anticipate spontaneous bone regeneration at immediate implants if the blood clot remains covered, regardless of graft or membrane usage.[15]

This is contrary to others' recommendations that regenerative techniques are needed when the labial plate is damaged.[16,17,18]

Chen (2004)[19] evaluated VDH, HDD, and HDW and stated that no statistically significant difference was observed for VDH and HDD with the use of bone graft over time and concluded that immediate and delayed immediate implants tend to be predictable modalities of treatment, with survival rates comparable to implants in healed ridges. Good clinical findings have been well developed in terms of bone filling for the peri-implant defect. However, as assessed by peri-implant tissue fitness, prosthesis stability, and esthetic outcomes, there was a lack of data on long-term performance. In the present analysis, the effect of reducing VDH, HDD, and HDW with or without the use of hydroxyapatite crystals in both Groups X and Y was evaluated and the findings showed a substantial difference. This is consistent with studies performed by Hammerle and Lang (2001)[13] and Goldstein (2002),[14] which strongly indicate the use of bone graft. In the present study, measurements were made at multiple sites within the same patients. The largest defect at each implant was opted for data analyses. This defect was considered to be the one having the greatest impact on the prognosis for implant survival. This is the accordance with a study done by Schropp et al.[7]

Paolantino (2001)[20] and Diago (2011)[21] evaluated immediate implants without bone grafts and reported that marginal bone loss was not present in any of the histological sections.

Due to its many advantages and disadvantages, the present work contrasts the immediate placement technique and delayed implant placement technique, namely the minimal use of surgical drills in immediate implant placement and the possibility of bone necrosis that enables bone remodeling to occur. A traditional approach with the advantage of less microbial contamination after implant placement is delayed implant placement. Implant placement causes a series that result from trauma during surgery, which is an important cause of implant failure. During the surgical process, the literature suggests avoiding unnecessary bone trauma as delayed implant placement plays a vital role in removing teeth, as the setting is more conducive to healing and the production of sufficient osseointegration.[4,5,19,22]

CONCLUSION

It was concluded from this study that clinical and radiographical bone healing in the delayed implant group with or without bone graft (Group Y) appears to be better than the immediate dental implant group with or without bone graft (Group X). The advantages of immediate implant placement over the delayed implant placement are elimination of the waiting period for socket ossification, fewer surgical sessions, shortened edentulous time period, reduced overall cost, preservation of alveolar bone height and width, decreased operatory time with less trauma to tissues, and less discomfort to the patient making immediate implant treatment more acceptable to patient and surgeon.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.