Background and Rationale:

Dental implants are used to rehabilitate missing teeth. Dental implants have become successful as a treatment option since they provide a superior alternative to conventional prosthetic treatment with long term results. They are considered to be better than fixed partial dentures since they offer several advantages like not involving the adjacent teeth which poses reduced risk of caries and less chances of uncemented restoration, improves hygiene conditions, decreased cold or contact sensitivity, improved esthetics, maintains the bone in site and reduces the chances of adjacent tooth loss.^1-3

 They are proven to provide long term success and predictable outcomes in patients.^4,5 The submerged healing period of about 3 to 4 months was deemed necessary for the osseointegration of dental implants with bone, whereas a too-early loading with excessive micromotion of dental implant could have deleterious effect on peri-implant tissue, leading to formation of a fibrous tissue at the bone-implant interface and fibrointegration of implants. With time, the paradigm has shifted towards installation of dental implants simultaneously with tooth extraction in fresh extraction socket. This technique is called as immediate implant placement. Earlier the implants were placed only after the bone was completely healed. Immediate implant placement provides several advantages like reduction in time prior the recovery of the masticatory function. Immediate implant placement is a therapeutic approach introduced in 1976 as an alternative to the classic delayed implant placement described by Branemark⁶. Immediate implants can be placed involving both the cortex of bone and a single cortex. When both cortexes are engaged, it is called bicortical anchorage.

 Implants can also be splinted to improve their stability. When combined with the use of more implants to support the entire prosthesis, the overall result is more predictable.⁷ One method of splinting implants is intraoral welding. The modern intra-oral welding protocol is a refinement of the technique reported by Mondani & Mondani (1982) and Hruska (1987). The welding process is subdivided into three stages: preparation, welding and cooling.⁸ In patients presenting with D3 and D4 bone density it’s difficult to obtain implant stability. Thus, the technique of intraoral welding can be used to improve the implant stability.⁹

The primary stability of implant plays an important role for implant stability during the first week after implantation, and thereafter reduces significantly to minimal levels at about 2 weeks postoperatively.^10,11 Whereas the primary stability of bone-implant contact sites are established by appropriate surgical anchoring techniques of the implants, ¹⁰ the secondary stability is based on a biological process called osseointegration. During osseointegration a new structural and physiological bony contact between the implant surfaces and the pre-existing as well as newly formed surrounding bone tissues is formed by inherent osteogenic activities. Over time, the secondary stability keeps on increasing continuously, and more rapidly increases about 2.5 weeks after implantation to achieve a plateau level at about 5 or 6 weeks after implantation. The whole transition process from the initially dominating primary stability phase to the finally dominating secondary stability phase lasts roughly 5–8 weeks.¹¹

Since there is a lacuna in available literature, this study is being done to compare the crestal bone loss and ISQ values in welded, immediately placed implants inserted with and without bicortical anchorage in D3 and D4 density bone and placed in immediate function for the rehabilitation of patients with partial edentulism.

Objectives

1.To compare the crestal bone loss in radiographic intervention through paralleling technique of intraoral radiography in intraoral welded, immediate implant in low density bone with and without bicortical anchorage.

2.     To compare the ISQ Value by Resonance Frequency Analysis (RFA)in intraoral welded, immediate implant in low density bone with and without bicortical anchorage.

3.     To assess patient satisfaction using OHIP-14 questionnaire in intraoral welded, immediate implant in low density bone with and without bicortical anchorage.

Materials and methods

 Study Setting:

 Self reporting partially edentulous individuals visiting the Department of Prosthodontics would be interviewed and examined clinically and will be included in the present study according to the inclusion and exclusion criteria.

Study Design: Split mouth randomized controlled clinical trial.

Randomization: After including the participant’s right or left side will be randomly allocated to one of the treatment groups as mentioned below:

1.     Experimental group:  Subjects with immediately placed and welded implants with bicortical anchorage. (Right/Left side)

2.     Control Group: Subject with immediately placed and welded Implants with monocortical anchorage. (Right/Left side)

Blinding: This is a triple-blind randomized controlled clinical trial. The clinician doing prosthetic rehabilitation, participants, and researcher performing the statistical analyses will be blinded to the side allocation.

Inclusion Criteria:

1. 40 to 60 years
2. Multiple posterior teeth indicated for extraction in bilateral posterior maxilla.
3. Adequate bone in width and height for insertion of an implant with 10-11mm length and 4-5 mm diameter
4. Adequate interocclusal space of 10mm
5. Group functional occlusion

Exclusion Criteria:

1. Patient unable to give written informed consent to participate
2. Opposing dentitions other than natural teeth.
3. Radiation therapy and chemotherapy in the craniofacial region within the previous 12 months
4. If they smoked >10 cigarettes/day, used tobacco or tobacco products within past one week.
5. Systemic diseases that could compromise osseointegration.
6. Patients with history of bone augmentation by artificial graft, in the position of proposed implant site.
7. Patients with pacemakers.

Sample Size

Sample size is calculated on the basis of cumulative survival rate in two treatment groups using the formula:

Where p₁ = 0.962 (96.2%) cumulative survival rate in first treatment group

p₂ = 0.848 (84.8%) cumulative survival rate in second treatment groups (Ref. Ivanoff CJ, Gröndahl K, Bergström C, Lekholm U, BrÃ¥nemark PI. Influence of bicortical or monocortical anchorage on maxillary implant stability: a 15-year retrospective study of BrÃ¥nemark System implants. Int J Oral Maxillofac Implants. 2000 Jan-Feb; 15(1):103-10. PMID: 10697944.)

e = 2(p₂ - p₁), the risk difference considered to be clinically significant

Type I error, α=5%

Type II error β=10% for setting power of study 80%

Loss to follow up = 20%

The minimum sample size required n = 22 in each group

Investigative Procedures and Interventions:

The participants would be selected following a detailed dental examination. Individuals who meet the inclusion criteria, would be enrolled into the study and informed consent will be taken. The right side of each patient will be randomized to either an experimental bicortical anchorage group with intraoral welding, or experimental group with monocortical anchorage and intraoral welding.

          Immediate loading with provisional restoration will be done in both groups. During follow up, mean crestal bone loss will be checked by radiographic intervention through paralleling technique of intraoral radiography and ISQ Value will be calculated by Resonance Frequency Analyser, at the time of provisionalisation (baseline), 3 months and 6 months and 1 year

Statistical analysis and data management:

The results will be analyzed using the IBM SPSS Statistics 20.0 program (IBM Corp., Armonk, NY, USA). Appropriate statistical tests and correlation will be used.

References:

1.              Adell R, Lekholm U, Rockler B, BrÃ¥nemark P-I. A 15- year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg 1981; 10:387- 416.

2.              Buser D, Weber HP, Lang NP. Tissue integration of nonsubmerged implants. 1-year results of a prospective study with 100 ITI hollow-cylinder and hollow-screw implants. Clin Oral Implant Res 1990; 1:33-40.

3.              Jemt T, Lekholm U, Gröndahl K. A 3-year follow up study of early single implant restoration ad modumBrÃ¥nemark. Int J Periodontics Restorative Dent 1990; 10: 341-349.

4.              Maló P, de Araújo NM (2011) Implants (3.3 mm diameter) for the rehabilitation of edentulous posterior regions: a retrospective clinical study with up to 11 years of follow-up. Clin Implant Dent Relat Res 13:95–103 2. Malo P, de Araújo NM (2011) Partial rehabilitation of the posterior edentulous maxilla using axial and tilted implants in immediate function to avoid bone grafting. CompendContinEduc Dent 32:60

5.              Balshi SF, Wolfinger GJ, Balshi TJ (2005) A prospective study of immediate functional loading, following the Teeth in a Day protocol: a case series of 55 consecutive edentulous maxillas. Clin Implant Dent Relat Res 7:24–31

6.              Schulte W, Heimke G. The Tübinger immediate implant. Quintessenz. 1976; 27(6):17–23.

7.              Becker CM, Kaiser DA, Jones JD, University of Colorado Health Science Center D. Guidelines for splinting implants. The Journal of prosthetic dentistry. 2000 Aug 1;84(2):210-4.

8.              Mondani PL, Mondani PM. The PierluigiMondani intraoral electric solder. Principles of development and explanation of the solder using syncrystallization. Rivista di odontostomatologia e implantoprotesi. 1982(4):28-32.

9.              Hruska AR. Intraoral welding of pure titanium. Quintessence international (Berlin, Germany: 1985). 1987 Oct;18(10):683-8.

10.           Degidi M, Nardi D, Piattelli A. Prospective study with a 2‐year follow‐up on immediate implant loading in the edentulous mandible with a definitive restoration using intra‐oral welding. Clinical oral implants research. 2010 Apr;21(4):379-85.

11.           Misch C.E. Bone character: second vital implant criterion. Dent Today. 1988;7(5):39.

12.           Raghavendra S, Wood MC, Taylor TD. Early wound healing around endosseous implants: a review of the literature. Int J Oral Maxillofac Implants. May-Jun 2005;20(3):425–431. 2. Cochran DL, Buser D, ten Bruggenk

13.           Huang H, Wu G, Hunziker E. The clinical significance of implant stability quotient (ISQ) measurements: A literature review. Journal of oral biology and craniofacial research. 2020 Oct 1;10(4):629-38.

14.           Ivanoff CJ, Gröndahl K, Bergström C, Lekholm U, BrÃ¥nemark PI. Influence of bicortical or monocortical anchorage on maxillary implant stability: a 15-year retrospective study of BrÃ¥nemark System implants. International Journal of Oral & Maxillofacial Implants. 2000 Jan 1;15(1).

15.           Pierrisnard L, Renouard F, Renault P, Barquins M. Influence of implant length and bicortical anchorage on implant stress distribution. Clinical implant dentistry and related research. 2003 Dec;5(4):254-62.

16.           Degidi M, Nardi D, Piattelli A. Prospective study with a 2‐year follow‐up on immediate implant loading in the edentulous mandible with a definitive restoration using intra‐oral welding. Clinical oral implants research. 2010 Apr;21(4):379-85.

17.           Tramonte, Silvano&Dominici, Aldo &Kurtzman, Gregori. (2011). Immediate Loading with Intraoral Welding for Improved Implant Stability during Healing. International Journal of Oral Implantology& Clinical Research. 2. 85-91. 10.5005/jp-journals-10012-1041.

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19.           PaÅ‚ka ŁR, Lazarov A. Immediately loaded bicortical implants inserted in fresh extraction and healed sites in patients with and without a history of periodontal disease. Annals of Maxillofacial Surgery. 2019 Jul;9(2):371.

20.           Ragucci GM, Elnayef B, Criado-Cámara E, Del Amo FS, Hernández-Alfaro F. Immediate implant placement in molar extraction sockets: a systematic review and meta-analysis. International Journal of Implant Dentistry. 2020 Dec;6(1):1-2.