|Year : 2013 | Volume
| Issue : 3 | Page : 354-360
Evaluation of single-tooth replacement by an immediate implant covered with connective tissue graft as a biologic barrier
SG Jyothi1, MG Triveni2, DS Mehta2, K Nandakumar1
1 Department of Periodontology and Implantology, Azeezia College of Dental Sciences and Research Centre, Kollam, Kerala, India
2 Department of Periodontology and Implantology, Bapuji Dental College and Hospital, Davangere, Karnataka, India
|Date of Submission||28-Aug-2012|
|Date of Acceptance||12-May-2013|
|Date of Web Publication||25-Jul-2013|
D S Mehta
Department of Periodontology and Implantology, Bapuji Dental College and Hospital, Davangere, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background and Objectives: The aim of the present study was to evaluate the survival rate of Screw-Vent ® immediate implants augmented with sub epithelial connective tissue graft for single-tooth replacement for 1 year. Materials and Methods: Ten patients (five men and five women), with the mean age of 25.3 years, were consecutively treated on the out-patient basis by the placement of Screw-Vent ® dental implants in to the fresh extraction sockets in association of augmentation with sub epithelial connective tissue graft harvested from the palate, supporting single crowns. The clinical and radiographic parameters were recorded to evaluate the peri-implant soft tissue health and marginal bone loss, respectively, for each patient at baseline and at every 3 months interval for 1 year. Results: The 1 year cumulative survival rate of Screw-Vent ® dental implants was 100% for all 10 patients. Statistical analysis demonstrated highly significant values indicating an improvement in peri-implant soft tissue parameters in terms of peri-implant aesthetic parameters, which estimated the keratinized mucosa width. Statistically, non-significant marginal bone loss or gain indicated stable condition in hard tissue parameters. Interpretation and Conclusion: Single-tooth replacement by Screw-Vent ® dental implants in to a fresh extraction socket, in association with guided bone regeneration using autologous connective tissue graft is a predictable treatment as demonstrated by the 100% implant survival rates and appreciable increase in the width of the keratinized mucosa at 1 year follow up.
Keywords: Guided bone regeneration, immediate implant, peri-implant aesthetics, sub epithelial connective tissue graft
|How to cite this article:|
Jyothi S G, Triveni M G, Mehta D S, Nandakumar K. Evaluation of single-tooth replacement by an immediate implant covered with connective tissue graft as a biologic barrier. J Indian Soc Periodontol 2013;17:354-60
|How to cite this URL:|
Jyothi S G, Triveni M G, Mehta D S, Nandakumar K. Evaluation of single-tooth replacement by an immediate implant covered with connective tissue graft as a biologic barrier. J Indian Soc Periodontol [serial online] 2013 [cited 2019 Nov 14];17:354-60. Available from: http://www.jisponline.com/text.asp?2013/17/3/354/115666
| Introduction|| |
Osseointegrated implants are the most advanced alternative in the treatment of patients who need oral rehabilitation. According to the Brånemark protocol, a healing period following tooth extraction has been recommended before implant placement,  extending the treatment period for several months; however, based on more recent evidence, immediate implant placement into fresh extraction sites has been considered as a predictable procedure. 
Immediate implants were first described by Schulte and Heimke in 1976  in a clinical report, followed by histologic studies that confirmed the procedure as successful. , The immediate implant is designed to prevent bone resorption following extraction. With this method, the ridge dimension and height are maintained  and a number of surgical procedures omitted, shortening the healing period.
One problem that remains unresolved with this procedure; however is that, due to the discrepancy in size and form between the extraction socket and the implant, there is usually a space left in the area surrounding the coronal portion of the implant, called "jumping distance."  The mucogingival condition around the extraction socket may be unfavorable for primary closure over the implant.
Various surgical techniques  have been proposed to achieve primary soft tissue closure and guided bone regeneration around the implants placed into extraction sites. However, the use of a connective tissue graft was first described by Edel  for immediate implants, to achieve primary closure over implants placed in extraction sockets in conjunction with guided bone regeneration around immediate implants, which allow for the undisturbed healing of peri-implant deep tissues. Connective tissue improves the local metabolic environment of the superficial soft tissues and preserves the keratinized tissue amount, obtaining a satisfactory peri-implant marginal sealing, which helps in achieving an optimal tissue conditioning and natural appearance of the prosthetic crown. 
The purpose of this study was to determine the survival rate of Screw-Vent ® implants placed immediately into extraction socket augmented with sub epithelial connective graft, by clinically evaluating the peri-implant soft tissue health, using clinical parameters and by radiographically evaluating peri-implant bone height - mesial and distal to the Screw-Vent ® implants, using Image J analysis, for 1 year after implant placement.
| Materials and Methods|| |
This study was approved by a human ethical committee and was designed as a case series study. Ten patients (five males and five females), with the mean age of 25.3 years were selected from the Out Patient Department of Periodontology and Implantology, Bapuji Dental College and Hospital, Davangere, Karnataka, India. The study was conducted for a period of 1 year. The selection criteria include patients with good systemic health with no contraindication for implant surgery, non-smokers and each patient having at least one tooth (maxillary and/or mandibular anterior or premolar tooth) indicated for extraction (due to root fracture, endodontic failure, grossly decayed tooth with no active infection present) [Figure 1]. Verbal and written informed consent was obtained from all patients before the commencement of the study.
|Figure 1: Tooth #25 indicated for extraction due to failure of post endodontic restoration|
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Each case was carefully evaluated using diagnostic casts for the intra-arch relationship. Intra oral periapical radiographs (IOPA) of the selected sites were taken by long cone parallelling technique. Panoramic radiographs were taken pre-operatively in order to examine the relationship of anatomical land marks to the tooth to be extracted. Pre-operative computed tomography-scans were taken in coronal and transverse sections, in order to select the implant size. All selected clinical cases needed tooth extraction in the frontal and premolar area [Table 1]. No bone dehiscences and no alveolar fenestrations were found.
Materials used in the study
Implant system used in this study was Screw-Vent ® implant system (Zimmer Dental, Carlsbad, CA, [USA]) developed by Dr. Gerald A. Niznick. Osteotomy drills available in the implant kit are of diameters 2.3, 2.8, 3.2, 3.8, 4.2 and 4.5 and lengths are calibrated at 9 mm, 11 mm, 14 mm and 17 mm. Implants available were of lengths 8 mm, 10 mm, 13 mm and 16 mm and of diameters 3.3 mm, 3.7 mm, and 4.7 mm.
Sub epithelial connective tissue graft
Autologous sub epithelial connective tissue graft was harvested from the palate by Bruno's technique  in all the 10 cases.
After the initial examination and treatment planning, all of the patients selected for the study underwent phase I therapy which included education, motivation, oral hygiene instructions, scaling and polishing. After 4 weeks of maintenance therapy, immediate implant surgical procedure was advised for the selected patients.
A similar implant-surgical protocol was followed for all cases. Under aseptic precautions, implant-surgical procedures were performed on an outpatient basis. Adequate local anaesthesia was achieved by 2% lignocaine hydrochloride containing 1:80,000 concentration of adrenaline by injecting to the corresponding nerve.
Crevicular incision placed around the tooth indicated for extraction with B.P. blade no. 12, followed by vertical incisions diverging apically along the line angles on either side of the tooth with B.P. blade no. 15 [Figure 2]. Full thickness mucoperiosteal flap raised up to muco-gingival junction, followed by partial thickness flap beyond the muco-gingival junction in order to facilitate for coronal advancing of the flap.
|Figure 2: Vertical and sulcular incisions placed with B.P. blade no.15 and 12 respectively|
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Minimally invasive extraction was performed using periotome to preserve the alveolar bony integrity. Socket was curetted to remove any infected or inflammatory tissue as well as remnants of the periodontal ligament [Figure 3].
Dimensions of the implants to be placed were decided by measuring the root length and width of the extracted tooth using caliper. Socket shaping and deepening was accomplished by sequential osteotomy with copious saline irrigation, using appropriate size drills. With aseptic precautions, the Screw-Vent ® dental implant was placed into the socket according to manufacturer's instructions [Figure 4]. Abutment was removed, implant platform was disinfected with metronidazole gel, and closed with the cover screw, and care was taken to keep the recipient site free of saliva and blood.
Required size of an autogenous connective tissue graft of ~ 1.5 mm thickness was harvested from the palate. The donor site was chosen between maxillary first premolar to maxillary first molar, 2 mm apical to the gingival crestal margin. The graft was removed by Bruno's technique  [Figure 5] and [Figure 6]. The donor site was sutured by horizontal suspension sutures using black braided (3-0) silk. The connective tissue graft was placed over the implant cover screw and was inserted under the facial and palatal flaps, which was stabilized by a 5-0 polyglactin (Vicryl, Ethicon, Johnson and Johnson, Somerville, NJ) resorbable suture material [Figure 7], followed by coronal advancement of facial flap, which was secured by interrupted sutures using black braided (3-0) silk in order to achieve primary wound closure [Figure 8]. Both recipient and donor surgical areas were protected and covered with non-eugenol dressing (Coe-Pack ® , G C America Inc, USA). All patients were prescribed systemic Amoxycilline 500 mg thrice daily for 5 days, Diclofenac sodium + Serratiopeptidase (Divon S) combination thrice daily for 3 days, and chlorhexidine mouth wash during the post-operative period.
10 days following surgery, the periodontal dressing and the sutures were removed and the area was thoroughly irrigated with saline and oral hygiene instructions were reinforced. The second stage surgery was performed 6 months after the initial procedure, for the placement of a healing abutment for a period of 4 weeks [Figure 9], followed by the cementation of the final implant prostheses on the final abutments [Figure 10] using zinc polycarboxylate - luting cement. Then, follow up was at 9 months and 12 months [Figure 11].
|Figure 5: Autogenous sub epithelial connective tissue graft harvested from the palate by Bruno's technique|
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|Figure 7: Connective tissue graft placed to cover the implant and stabilized by Vicryl (5-0) resorbable suture|
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|Figure 8: Buccal flap was coronally repositioned and sutured to achieve primary closure|
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|Figure 11: Patient at the end of follow-up period (12 months after implant placement)|
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The stability of the implant and health of the peri-implant soft tissue was clinically evaluated at 6 months, 9 months and 12 months after implant placement by means of the following indices: Presence or absence of mobility,  probing depth (PD)  and probing attachment level (PAL),  measured using a Vivacare true pressure-sensitive ® probe at four sites (mesial, facial, distal and palatal/lingual) for each implant from the implant shoulder to the base of the peri-implant sulcus. Presence or absence of pain and discomfort, presence or absence of suppuration, plaque index,  gingival index,  sulcular bleeding index,  keratinized mucosa width (KMW) were recorded at baseline, 3 months, 6 months, 9 months and 12 months post-operatively.
The following radiographic parameters were evaluated for each patient at baseline, 3 months, 6 months, 9 months and 12 months after surgery: IOPA were taken to evaluate the presence of peri-implant radiolucencies, and to evaluate the marginal bone loss by measuring the linear distance between implant shoulder and first implant-bone contact (DIB) using Image J analysis software , at baseline (immediate post-operative) [Figure 12] and at every 3 months interval up to 1 year after implant placement [Figure 13].
|Figure 12: Immediate post-operative radiograph (baseline). Linear radiographic interpretation with computer image analysis software. (Yellow line indicates distance from implant shoulder to first implant-bone contact)|
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|Figure 13: 12 months post-operative radiograph. Linear radiographic interpretation with computer image analysis software. (Yellow line indicates distance from implant shoulder to first implant-bone contact)|
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Descriptive data that included mean ± SD and percentages were calculated for each clinical and radiographic parameter, at baseline and at different time intervals. Paired t-test was used to compare the post-operative changes with baseline. A level of significance was set at the probability value of P < 0.05.
| Results|| |
The surgical protocol, which combined immediate implant placement and sub epithelial connective tissue graft, proceeded smoothly. All patients included in the present study were followed carefully for 1 year. The post-surgical healing phase was uneventful for all patients. Among 10 patients, 4 patients elicited pain and discomfort at baseline (initial implant placement). However, no patients had any signs and symptoms or complications at 3 months, 6 months, 9 months and 12 months post-operative period. At the second stage surgery, the implants were asymptomatic, immobile and osseointegrated. No peri-implant bony defects were observed when the sites were probed.
No signs of infection or bleeding were detected on probing sites. There was a reduction in plaque index, gingival index and sulcular bleeding index from baseline to 12 month-time period, which was statistically significant. All sites that showed a PD value <3 mm were considered healthy. Our results showed a mean decrease in PD values [Table 2] and PAL values [Table 3] from baseline (6 months) to 12 months post-operative period which were statistically significant. The evaluation of aesthetic results was assessed using KMW parameters. The mean values of KMW of 3 mm were considered acceptable for aesthetic purposes. Our results showed that all patients treated by immediate implant combined with sub epithelial connective tissue graft had a KMW value >3 mm at the end of the follow-up period, was statistically highly significant [Table 4].
Radiographic evaluation of intraoral periapical radiograph of the implant with Image J Analysis at mesial and distal sites revealed a slight increase in DIB values from 2.66 mm at baseline to 2.97 mm at 6 months with a difference of 0.31 mm (suggesting bone loss) and a slight decrease in DIB values from 2.97 mm at 6 months to 1.63 mm at 12 months with a difference of 1.34 mm (suggesting bone gain) [Table 5] and Graph 1], indicating bone remodeling as well as the beneficial effect of guided bone regeneration around the implant. But the values were not statistically significant, denoting a stable condition of the peri-implant hard tissues.
The implants were deemed successful at 6 months after prosthetic rehabilitation according to the clinical criteria suggested by Albrektsson et al. 
| Discussion|| |
The important goal of modern dentistry is to provide a healthy and beautiful smile that is accompanied by a functional and comfortable dentition. There are various treatment modalities available for the replacement of missing teeth. Among which dental implant placement, especially immediate implant placement is the most advanced treatment modality, which has proven to be a predictable treatment protocol with a very high success rate. Immediate implant placement has several advantages, such as a reduction of the number of surgical treatments, reduction of time between tooth extraction, and placement of the definitive prosthesis. 
Achieving peri-implant aesthetics and regeneration of bone in the "jumping distance" around an immediate implant in the aesthetic zone of the oral cavity is a challenging procedure, and maintaining it over time can be an equally demanding task. When the "jumping distance" is >2 mm, the use of barrier membranes has been recommended to obtain bone regeneration and to prevent soft tissue growth, at the bone-implant interface. However, there are several clinical complications, membrane exposure, , bacterial colonization and infection, which can lead to failure of the implant. The need of barrier membranes should therefore be carefully evaluated. Guided bone healing procedures using a connective tissue graft to cover the residual alveolar defect associated with an immediate implant are valid alternative protocols and can lead to undisturbed peri-implant healing. , On the contrary, there can be a very minute chance of infiltration of fibroblasts from the connective tissue graft in to the jumping distance, as the underlying surface of the connective tissue graft is lined by peri-osteum layer. The evidence for such findings are not documented, recorded and published in the literature. Therefore, there is no solid proof saying that fibro-osseous integration occurs after connective tissue grafting, but there may be a possibility of migration of fibroblasts in to the jumping distance if primary closure over the implant has not been attained perfectly.
The single-step technique performed in this study included tooth extraction, immediate implant placement, a sub epithelial connective tissue graft placement, and coronal advancement of the facial flap. This single-step technique is desirable for aesthetic reasons. The connective tissue graft seems to prevent the complications induced by the use of synthetic barrier membrane, and at the same time, improves the local metabolic environment of the superficial tissues, thus preserving the keratinized tissues. The second stage surgery was performed 6 months after implant placement. The definitive prosthetic restoration took place 6 months after the first surgery and was of great importance to recreate an aesthetic profile of peri-implant soft tissues.
The patients showed good oral hygiene performance. The peri-implant indices showed a decreasing tendency of PD values at the end of the follow-up period compared to baseline values. The analysis of PAL values showed a similar behavior in the scores. The radiographic assessment was carried out by analyzing linear DIB using Image J analysis software as the digitizing unit gives the precise value. The analysis of DIB values showed increasing tendency from baseline to 6 months and a decreasing tendency from 6 months to 12 months, indicating normal process of bone remodeling for first 6 months and the beneficial effect of guided bone regeneration procedure in the next 6 months of follow-up, resulting in good stabilization of peri-implant hard tissues at 12 months post-operatively. These results are comparable with the outcome reported by Bianchi and Sanfilippo. 
In the aesthetic zone, morphology of the soft tissues played a crucial role in the achievement of satisfactory final results. The evaluation of the aesthetic result by KMW parameters has shown that all patients treated by an immediate implant combined with sub epithelial connective tissue grafts had KMW values >3 mm at the end of the follow-up. A KMW value of 3 mm was the minimal result considered acceptable for an aesthetic as well as functional outcome. The mean value of KMW was 4.16 ± 0.36 mm at the end of the follow-up period. These results are also comparable with the outcome reported by Bianchi and Sanfilippo. 
In cases with normal as well as deficient soft tissue configuration, our results confirm that sub epithelial connective tissue grafting with coronal advancement of the facial flap around immediate implant, can increase the height and thickness of the peri-implant soft tissue, thereby enhancing peri-implant health and peri-implant aesthetics.
| Conclusion|| |
The placement of implants in fresh extraction sites associated with immediate sub epithelial connective tissue grafting and coronal advancement of facial flap was shown to be a valid treatment procedure that produces predictable results for the non-salvageable teeth. This single-step technique performed in this study was shown to improve the quality of the peri-implant soft tissues and hard tissues at the end of 12 month follow-up. However, long term studies are necessary before using this technique routinely in implant treatments.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]