1110
Placement of Implants Into Fresh Extraction Sites: 4 to 7 Years Retrospective Evaluation of 95 Immediate Implants Devorah Schwartz-Arad* and Gavriel Chaushu1
A 7-year follow-up of implants placed immediately after tooth extraction into fresh extraction sites is reported. Small autogenous bone chips (from bone adjacent to implant sites) were grafted into the defect between the implant and the socket walls when needed. Closure of the wound was obtained by coronal repositioning of the flap, and no membranes were used. Care was taken to minimize hematoma formation under the flap during healing by part-time use of removable prosthesis with thick soft linings after implant surgery. 'At second stage surgery, mucoperiosteal flaps were apically repositioned for maximum attached gingival width and to reconstruct the vestibule. Minor complications such as exposure occurred in 16% of cases. Implant mean 5-year cumulative survival rate was 95%. There was no implant loss after loading. The results indicated that implants placed into fresh extraction sites grafted with autogenous bone chips will heal predictably. J Periodontol 1997;68:1110-1116.
Key Words: Dental implants; bone transplantation; grafts, bone; surgical flaps; wound healing; tooth extraction/rehabilitation; retrospective studies.
Immediate implantation has provided implant dentistry the opportunity to achieve better and faster functional and esthetic results. The localized bone defects surrounding implants placed immediately into fresh extraction sites present a challenge to the surgeon. The use of barrier membranes and different graft materials has been widely documented, yet complication ratios are still very high.1-18 The number of human studies encompassing more than 20 immediate endosseous implants is limited.l0J 8-24 The purpose of this study was to evaluate the survival rate of implants placed into fresh extraction sites without the use of barrier membranes. Changes in vertical defect height and the correlation between complications and the use of temporary dentures immediately after implant placement were also evaluated.
MATERIALS AND METHODS From the years 1989 to 1993, 49 patients (19 men and 30 women), ranging in age from 30 to 75 years (mean *Department of Oral and Maxillofacial Surgery, The Maurice and GaGoldschleger School of Dental Medicine, Tel Aviv University, Tel
briela
Aviv, Israel. 'Section of Oral and Maxillofacial
Center, Tel Hashomer, Israel.
Surgery,
45), presented for immediate implant* placement into 95 fresh extraction sites, performed in one clinic by the senior surgeon (DSA). Ninety-seven percent (97%) of the
implants used were screw-type, and 3% were cylindertype. Twenty-five percent (25%) of the implants were hy-
droxyapatite-coated. As a site for immediate implant placement, teeth had to demonstrate 3 to 5 mm of bone beyond the root apex. Teeth without a labial plate, described in 1993 by Gelb10 as a "no-wall" defect and periapical lesions, were excluded. Indications for tooth extraction and immediate implant placement included prosthetic
reasons (root fractures, non-restorable carious lesions, residual roots, trauma), severe periodontal attachment loss, combined endodontic failure and periodontal attachment loss, and esthetics. Oral examination
included on the intra-arch relationship, the bucco-lingual width and the intermaxillary relationship. Radiographs were evaluated for bone quantity (mesio-distal width, residual bone beyond the apex, socket width) and root angulation. Bone quality was retrospectively evaluated from the pre-operative radiographs. Amoxicillin (lg) and dexamethasone (8 mg) were administered 1 hour prior to surgery. For the penicillin-al-
The Chaim Sheba Medical
'•Dentsply,
Inc.
(now Core-Vent, Inc.),
Las
Vegas,
NV.
Volume 68 Number 11 Table 1.
SCHWARTZ-ARAD, CHAUSHU Table 5.
Reasons for Tooth Extraction Extracted Teeth
Reason
Table 2.
Implant
Maxilla Mandible Total
Table 3.
implants patient patient Total implants
29 5
12
implants
Total
28 3 5.7
72 23 95
per Patient
1
2
3
4
5
6
7
8
Total
33 33
7 14
1 3
3 12
1 5
1 6
2 14
1 8
49 95
A*
B:
15 8 23
25 7 32
sUp "Up to
5.80
Molar
Premolar
Implant Placement According
marginal
Mean
Location
6
Maxilla Mandible Total to to to
by
Canine
Vertical Bone Loss Type
fUp *Up
Initial
9 11 18 4 45 8 95
Incisor
Number of
per
Table 4.
Placement
Changes in Defect Height Adjacent to 79 Implants (1991Defect
Prosthetics Root fractures Non-restorable carious lesions Residual root Trauma Severe periodontal disease Combined causes Total
*No
1993)
to Bone
Quantity
Cs
D5
E"
Total
29 6 35
3 2 5
0 0 0
72 23 95
loss.
0.33. 0.5. 0.75. 1.
the drug of choice. lergic patients, 0.5 g erythromycin continued or for 5 to 7 Amoxicillin erythromycin was dexamethasone and 4 mg per day was days postsurgery 2 administered for additional days. Flaps were designed to attain primary closure. Vertical releasing incisions were performed. Teeth were carefully removed and the sockets debrided. Sockets were prepared with standard drills using the bony walls as guides, with maximum use of bone apical to the extraction sockets. The longest (14.7 mean) and widest (3.8 mean) possible implants were placed at the eresiai ridge to achieve normal emergence profile and maximal vertical bone preservation. Implants were determined to be clinically stable. The initial defect height was determined for 79 implants placed from 1991 onward. Small autogenous bone chips (from bone adjacent to the implant site or bur debris) were grafted into the defect between the implant and the socket walls when needed. After releasing periosteal incisions, the flap was coronally repositioned and sutured (a technique resembling closure of oroantral fistula), ensuring was
1111
(SD) (3.1)
height (mm) Stage (Final)
Second Mean 0.54
(SD) (0.5)
Change 5.26
mucoperiosteal coverage of the implant and bone chips (Fig. 1). Removable prostheses were adjusted with a thick layer of soft lining and inserted immediately at the end of the surgical procedure when esthetics were critical. Patients were instructed to wear the immediate prosthesis only as necessary for esthetics or function to minimize the total wearing time. The prosthesis was not worn during the night, except for the first 24 hours. The average daily use was 10 to 12 hours. Single tooth immediate-removable prosthesis attained maximal support from the adjacent teeth or soft tissue to
minimize direct contact with the soft tissue coverage of the implant. The patients were seen at least once a month prior to second stage surgery. At second stage surgery (a mean of 6.2 months in the maxilla and 3.5 months in the mandible after implantation), radiographs of the implant sites were taken. Mucoperiosteal flaps were apically repositioned for maximal attached gingival width and reconstruction of the buccal vestibular depth (Fig. 2). Excess bone over the implants was removed by blade. Residual defect depth was measured. Healing caps were placed and, after varying intervals, the implants were restored with fixed prosthesis by several prosthodontists.
RESULTS The reasons for tooth loss are listed in Table 1. Out of 95 teeth, 47% (45) were extracted due to severe periodontal attachment loss, 44% (42) for prosthetic reasons, and 8% (8) for combined periodontal-prosthetic complications. One implant was placed in 1989 (1 patient); 14 in 1990 (5 patients); 18 in 1991 (7 patients); 23 in 1992 (18 patients); and 39 in 1993 (18 patients). Follow-up was from the time of implant placement up to 1996. Table 2 shows implant location by jaw and tooth position: 72 implants were placed in the maxilla and 23 in the mandible. Most of the implants were placed in the incisor (34) and premolar (33) regions. Single implants were placed in 67% of the patients, 23% had 2 to 4 implants and 10% had 5 to 8 implants (Table 3). Bone quantity is described in Table 4. A modification of the classification described by Becker et al.16 was used. To avoid confusion between bone quality and bone quantity, the number 1, originally added to the A- classification by Becker et al.,16 was removed. The classification was performed retrospectively and was based solely on radio-
1112
J Periodontol November 1997
IMPLANTS IN FRESH EXTRACTION SITES
Figure 1. (A, B, and C) Flap design (resembling closure of oroantral fistula), the periosteal releasing incisions are performed only at the base of the flap ensuring mucoperiosteal coverage of the implant and bone chips. was 5.8 mm. At second stage surgery the mean defect depth was 0.54 mm. Minor complications were defined as implant exposures requiring the use of Chlorhexidine rinses and oral antibiotics without surgical intervention. Major complications were defined as implant exposures requiring surgical intervention for curettage and primary closure. Table 6 shows the complications between those patients wearing an immediate temporary prosthesis (n 21; 43%) and those without (n 28; 57%). Overall, complications were found in 13 implants (21%) in those patients with an immediate denture and 10 implants (29%) in patients with-
depth
=
=
out.
The distance from the cemento-enamel junction alveolar crest was measured and divided by the distance from the CEJ to the root apex. The classification was based on this ratio. Vertical bone loss (VBL) type A (VBLA) demonstrated no marginal loss; VBLB, up to 0.33, VBLC, up to 0.5; VBLD, up to 0.75; and VBLE, up to 1. The average between the mesial and distal ratio was calculated. Ninety (90) implants were placed in VBL types A through C, 5 in VBLD, and none in VBLE. Table 5 presents the initial and final defect depth in 79 implants (these measurements were started only from the second implant placed in 1991). The initial mean defect
graphs. (CEJ)
Table 7 presents the 7-year (mean 5 years) cumulative survival rate. Implant survival rate was 94.7%. Five implants were lost, 4 during healing time and 1 after second stage surgery (Table 8). All 5 patients were healthy. We
to the
Table 6. Implant Complications in Patients Wearing Immediate Removable Temporary Dentures Versus Patients Without Temporary Dentures
Complications
Immediate
Temporary Dentures
With Without Total
Patients 21 28 49
(43%) (57%)
Implants 61 (64%) 34 (36%) 95
Minor* 8 7 15
(13%) (20%) (16%)
Fail
Major 2 1 3
(3%) (3%) (3%)
3 2 5
(5%) (6%) (5%)
- "Premature implant exposure not requiring surgical intervention. 'Premature implant exposure requiring curettage and primary closure.
Figure 2. (A, , C, and D) Apically repositioning prevent recession of the adjacent papillae.
of the flap designed as
unable to detect any specific conditions under which failures occurred. There was no implant loss after loading. were
DISCUSSION The purpose of this retrospective study was to evaluate the survival rate of implants placed immediately into
a
trapezoid configuration.
The vertical
releasing
incisions
are
performed to
fresh extraction sites. Barrier membranes were not used and the only graft material was autogenous bone chips. The use of temporary dentures immediately after the surgical procedure was evaluated for the first time. The results of this study indicated that the variety of implants placed immediately into fresh extraction sites
J Periodontol November 1997
IMPLANTS IN FRESH EXTRACTION SITES
1114 Table 7.
Cumulative
Implant Survival
Rate
Implants
Cumulative Survival Rate (%)
5 0 0 0 0 0 0 0
94.7 94.7 94.7 94.7 94.7 94.7 94.7 94.7
Failed
Follow-Up (years)*
Implants'
1" stage surgery 2"d stage surgery 1 y 2 y 3 y 4 y 5 y 6 y 7 y *Mean 5 years. +95 first stage surgery; 90
95 90 90 90 90 90 56 33 15
=
=
=
second stage surgery.
will heal
predictably (95% survival rate). These findings compatible with the cases reported by Evian and Cutler.25 This application enhances the usefulness of these types of implants. The results also resembled those for other types of implants;1018-24 however, 65% of the implants in the present study were part of a fixed prosthesis replacing more than one tooth. The insertion level of the implant into the alveolar bone is crucial. Implant placement more than 2 mm below the alveolar crest might prevent bone preservation, one of the main advantages of immediate implantation and optimal esthetic results. All of the implants in this study were placed at the alveolar crest level, which did not constitute an impediment to the desirable outcome.1018 24 After inserting the implant, a gap remains between the occlusal part of the implant and the surrounding socket walls. A variety of materials may be used to fill this empare
ty space. Barrier membranes alone or in combination with
graft materials
can be applied clinically for augmentation of fresh extraction sites after immediate implantation.1-17 Measurement of the changes in vertical defect height serves to evaluate the bone regeneration success of such
procedures.16-20
The results of the present study showed that immediate succeed even without the use of barrier membranes in cases of VBL A through D. The mean change of defect height was 5.3 mm between first and second stage surgery without using barrier membranes, which resulted in lower complication ratios (24%) compared to previously reported studies using barrier membranes. Gelb10 included the use of polytetrafluoroethylene
implantation can
Table 8. Time After 2 2 2 6 1
Characteristics of Failing
Implantation
weeks months months months (at 2ml stage) month (post 2nd stage)
(ePTFE) membranes among his regenerative protocols for immediate implants in humans. At least 39% of the membranes were removed prematurely (earlier than 8 weeks). Becker et al.16 determined the predictability for implants placed into immediate extraction sites and augmented with ePTFE membranes in humans. They found that 41% of the membranes were removed prematurely due to either exposure or infection. Celleti et al.17 evaluated the efficacy of guided tissue regeneration around immediate implants in beagle dogs. Defects around the implants were covered with ePTFE and titanium membranes. The greatest average gain in bone height was seen in the control sites not receiving any membranes. All of the titanium membranes and half of the ePTFE membranes were exposed. Therefore, the use of barrier membranes, first introduced for immediate implantation by Lazarra1 in 1989, is open to question today. Fenestrations and dehiscences can still serve as limited indications. Future studies are needed to develop the ideal membrane material and de-
sign. Autogenous bone
is the optimal graft material in maxreconstructive illofacial procedures, since it has both osteoconductive and osteoinductive properties.20 Different graft materials have been used to fill gaps in immediate implantation. Demineralized freeze-dried bone allografts (DFDBA) were believed to be superior to other graft materials and were widely used.20-21-26-27 However, it has been suggested that DFDBA particles may inhibit bone formation.26 The results of the present study support the use of autogenous bone graft in immediate implantation due to its osteoinductive and osteoconductive ability, low cost, availability, and safety. Flap closure is regarded as one of the most important 24 components of the immediate implant procedure.1017 The alveolar soft tissue opening resembles the mucogingival status in the oro-antral fistula. The maxillofacial literature describes many methods to close oroantral fistula. In this study the buccal flap was used. The flap design included periosteal and vertical releasing incisions for sufficient flap mobility and a coronally repositioned flap. Reduction in vestibular depth at first stage surgery was corrected at second stage surgery by the use of an apical repositioning flap. Some authors question the need for primary closure in immediate implantation.1-13 Future research will hopefully resolve this dispute.
Implant Site
Second mandibular molar Maxilla canine First mandibular molar Maxilla lateral Mandibular canine
Reason for Tooth Extraction
Residual root Periodontal Residual root Trauma Non-restorable carious lesion
Implant Length (mm) 13 16 16 16 16
Implant Type Cylinder, HA-coated Screw Screw Screw Screw
Volume 68 Number 11
SCHWARTZ-ARAD, CHAUSHTJ
in implant failure, are inevitable. Previous studies allow the use of temporary dentures only 2 weeks after implant placement.1018 24 Even then, as little function as possible is recommended. To the best of our knowledge, the present study is the first to report the use of temporary dentures immediately after implant placement. The prostheses reduce the dead space between the soft tissue coverage and bone following implant placement and, due to their immediate pressure, reduce the initial hematoma. This minimizes the chances of infection and enhances the process of healing. The obvious social, functional, and economic advantages as a result of the immediate use of temporary dentures did not result in a higher ratio of complications or implant failure (Table 6). Patients should be closely followed. Temporary dentures which cause pressure sore points should be ad-
Complications,
justed
as soon as
not
necessarily resulting
possible.
long-term functional stability of immediate imbe considered. The longitudinal follow-up (4 must plants to 7 years) in this study supports the functional stability of immediate implants regardless of the initial defect height and volume of bone regenerated. These24results are compatible with previously reported data.1018 In conclusion, implants placed into fresh extraction The
sites will heal predictably. The use of autogenous bone graft without membranes and primary flap closure results in low complication ratios. The use of temporary dentures immediately postsurgery shows high survival rate ratios without additional complications. The longitudinal functional stability of immediate implants proves that immediate implantation must be considered as an optional treatment plan when teeth have to be extracted, unrelated to the number of hopeless teeth.
REFERENCES 1. Lazzara RJ. Immediate implant placement into extraction sites: Surgical and restorative advantages, lnt J Peridontics Restorative Dent
1989;9:333-343. 2. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: Surgical techniques and case reports, lnt J Periodontics Restorative Dent
1990;10:377-391. 3. Warrer K, Gotfredsen K, Hjorting-Hansen E, Karring T. Guided tissue regeneration ensures osseointegration of dental implants placed into extraction sockets. An experimental study in monkeys. Clin Oral Implant Res 1991;2:166-171. 4. Becker W, Becker BE, Handelsman M, Ochsenbein C, Albrektsson T. Guided tissue regeneration for implants placed into extraction sockets: A study in dogs. J Periodontol 1991;62;703-709. 5. Caudill RE Meffert RM. Histologie analysis of the osseintegration of endosseous implants in simulated extraction sockets with and without e-PTFE barriers. Part I: Preliminary findings, lnt J Periodontics Restorative Dent 1991;11:207-215. 6. Sevor JJ, Meffert R. Placement of implants into fresh extraction sites using a resorbable collagen membrane: Case reports. Pract Periodontics Aesthet Dent 1992;4:35-41.
1115
7. Becker W, Lynch SE, Lekholm U, et al. A comparison of ePTFE membranes alone or in combination with platelet derived growth factors and insulin like growth factor-1 or demineralized freeze dried bone in promoting bone formation around immediate extraction socket implants. J Periodontol 1992;63:929-940. 8. Wilson TG. Guided tissue regeneration around dental implants in immediate and recent extraction sites: Initial observations, lnt J Periodontics Restorative Dent 1992;12:184-193. 9. Novaes AB Jr, Novaes AB. IMZ implants placed into extraction sockets in association with membrane therapy (Gengiflex) and porous hydroxyapatite: A case report. Int J Oral Maxillofac Implants
1992;7:536-540. 10. Gelb DA. Immediate implant surgery: Three-year retrospective evaluation of 50 consecutive cases, lnt J Oral Maxillofac Implants 1993; 8:388-399. 11. Gotfredsen K, Nimb L, Buser D, Hjorting-Hansen E. Evaluation of guided bone generation around implants placed into fresh extraction sockets: An experimental study in dogs. J Oral Maxillofac Surg
1993;51:879-886. 12. Novaes AB Jr, Novaes AB. Bone formation over a TÌA16V4 (IMZ) implant placed into an extraction socket in association with membrane therapy (Gengiflex). Clin Oral Implant Res 1993;4:106-110. 13. Schultz AJ. Guided tissue regeneration (GTR) of non submerged implants in immediate extraction sites. Pract Periodontics Aesthet Dent 1993;5:59-65. 14. Caudill R, Lancaster D. Histologie analysis of the osseointegration of endosseous implants in simulated extraction sockets with and without e-PTFE barriers. Part II: Histomorphometric findings. J Oral
Implantai 1993;19:209-215. 15. Lekholm U, Becker W, Dahlin C, Donath , Morrison E. The role of early versus late removal of GTAM membranes on bone formation at oral implants placed into immediate extraction sockets. An experimental study in dogs. Clin Oral Implant Res 1993;4:121-129. 16. Becker W, Dahlin C, Becker BE, et al. The use of ePTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: A prospective multicenter study, lnt J Oral Max-
illofac Implants 1994;9:31-40. 17. Celletti R, Davarpanah M, Etienne D, et al. Guided tissue regeneration around dental implants in immediate extraction sockets: Comparison of e-PTFE and a new titanium membrane. Int J Periodontics Restorative Dent 1994;14:243-253. 18. Ashman A. An immediate tooth root replacement: An implant cylinder and synthetic bone combination. J Oral Implantai 1990;16: 28-38. 19. Yukna RA. Clinical comparison of hydroxyapatite coated titanium dental implants placed in fresh extraction sockets and healed extraction sites. J Periodontol 1991;62:468-472. 20. Becker W, Becker BE, Polizzi G, Bergstrom C. Autogenous bone grafting of bone defects adjacent to implants placed into immediate extraction sockets in patients: A retrospective study, lnt J Oral Max-
illofac Implants 1994;8:389-396.
21. Block MS, Kent JN. Placement of endosseous implants into tooth extraction sites. J Oral Maxillofac Surg 1991;49:1269-1276. 22. Augthun M, Yildirim M, Spiekermann H, Biesterfeld S. Healing of bone defects in combination with immediate implants using the membrane technique. Int J Oral Maxillofac Implants 1995;10:421-428. 23. Lang NP, Bragger U, Hammerle CH, Sutter F. Immediate transmucosal implants using the principle of guided tissue regeneration. I. Rationale, clinical procedure and 30-month results. Clin Oral Implant Res 1994;5:154-163. 24. Gher ME, Quintero G, Assad D, Monaco E, Richardson AE. Bone grafting and guided bone regeneration for immediate dental implants in humans. J Periodontol 1994;65:881-891. 25. Evian CI, Cutler S. Autogenous gingival grafts as epithelial barriers for immediate implants: Case reports. J Periodontol 1994;65:201210.
1116 26.
IMPLANTS IN FRESH EXTRACTION SITES
Spampata R, Werther JR, Hauschka PV. Accelerated endochondral osteoinduction in the absence of bone matrix particles in a rat model system. J Oral Maxillofac Surg 1992;50:140-151. 27. Schwartz-Arad D, Chaushu G. The ways and wherefores of immediate placement of implants into fresh extraction sites: A literature review. J Periodontol 1997;68:915-923.
J Periodontol November 1997 Send reprint requests to: Dr. Devoran Schwartz-Arad, Department of Oral and Maxillofacial Surgery, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. Fax: 972-3-5497368; e-mail:
[email protected] Accepted for publication April 14, 1997.
