1.Introduction

i.  Origin of the proposal – Implant dentistry has taken center stage in past few decades owing to all the advantages it offers in terms of advanced prosthetics and patient satisfaction. In all the quadrants of the oral cavity, implants, and implant-supported prostheses have shown a very high success rate. Of all the different surgical modalities in implants, there are basically three major categories i.e Immediate placement - placement of an implant just after extraction, Early placement of implant after soft tissue healing (4-8 weeks), and Delayed placement of implant after a minimum period of three months.

In the anterior maxilla and mandible, because of aesthetic considerations, patient demand and favorable anatomy, has almost become usual to place immediate implants after extraction. However, in posterior regions of the oral cavity, because of the presence of maxillary sinus and inferior alveolar nerve, complex and multiple roots of the tooth, and difficulty in attaining a perfect soft tissue closure at the time of surgery, immediate placement is most of the time ruled out and delayed placement is considered very safe.

There are specific advantages and disadvantages of each type of surgical protocol and for the treating clinician many times it is not clear as to which approach will be the best in a particular clinical situation. Stability the success of Osseointegration and the durability of implants is a key factor. It is usually measured by Resonance Frequency Analysis at the time of implant placement. RFA has now become very popular among implantologists as it is non-invasive. It was first introduced by Meredith et al in the year 1996. It is measured in a unit called Implant Stability Quotient,(ISQ). The most recent version is Osstell Mentor that is commonly used nowadays to measure RFA. ISQ is measured in numbers between 1 to 100 in which the former is the lowest and the latter the highest degree of stability.

In this study with the help of the number of samples, we will determine statistically as to whether there is a significant difference between the primary and secondary stability achieved after implant placement and after six months of healing period in immediate, early and delayed implant placed in the maxillary anterior region.

This study highlights the timing of implant placement in the maxillary anterior region.

ii. Novelty –  In this particular in vivo study, we will evaluate and compare the difference in ISQ readings in Immediate, Early, and Delayed placed implants in the maxillary anterior region after six months.

iii. Applicability-   The advantage of immediate placement of implant is the avoidance of concomitant healing of bone post extraction, therefore shorter loading phase.  The advantage of early placement of implant is the adequate soft tissue closure and avoidance of any active pathology. However, the bone is still very immature. The advantages of delayed placement is the straight forward nature of surgery, good primary stability, and soft tissue closure. For the success of dental implants, the important diagnostic determinant is stability, therefore treating implant patients and selecting the implant loading protocol clinical measurements can help dentists in treatment. 

iv. Outcome:  The possible outcome of this study is the correlation between increments from primary to secondary stability of implants in terms of ISQ values in different surgical modalities i.e., Immediate, Delayed and Early placement. This might lead to the clinical inference that one type of surgical modality (i.e. Immediate, Early or Delayed) is superior to other in terms of increment in ISQ from primary to secondary stability and lead to a better prognosis. The amount and quality of bone as well as the type of implant (passive or active) determine stability of the implant in the maxillary anterior region.

2.Aim and Objectives:

i. Aim: The aim of this study is to evaluate and compare the difference of ISQ readings in Immediate, Early and Delayed placed implants in maxillary anterior region after six months.

ii. Objectives:  

·       Primary objective - To observe the increment in ISQ readings in Immediate, early and delayed placed implants in anterior maxillary region after six months.

Secondary objective:  To compare and evaluate the differences in ISQ readings between Immediate, Early and Delayed placed implants in maxillary anterior region at baseline and after six months

Material and Methods

i.          Study design:

      In- vitro/In-vivo/Ex-vivo/Survey – In vivo

      Type of Study - clinical study

i.          Sample selection:

Inclusion criteria

Class I and II situations of sagittal root position. (SRP classification Kan J et al  20

 Age exceeding 21 years and below 60 years

Overall good health

  Absence of systemic diseases that could impact bone metabolism and wound healing;

  Patient’s willingness and ability to adhere fully to the study protocol;

  The provision of written informed consent

  Need of implant placement in maxillary anterior region

Exclusion criteria

       Immune-compromised status, including HIV infection or chemotherapy within the past 5 years;

     Pregnancy or lactation patients during any part of the study

     Poor oral hygiene motivation,

     Psychological or psychiatric disorders

     Systemic disease that amount to contraindication for surgery

       Chronic Smokers

      Bruxism, & lack of posterior occlusion.

    Presence of active infection around failing teeth or previously placed implant.

    Cases requiring guided bone regeneration will not be included in this study.

Discontinuation criteria

     Failed implants

     Patient further unwilling to participate

    Patient did not turn up on follow-up appointment

iii. Sampling :

Sample size/ number of participants: 90

    At site : 90 ( SARDAR PATEL POST GRADUATE INSTITUTE OF DENTAL AND MEDICAL SCIENCES).

      In India  : N/A 

      Globally : N/A

      Control group : N/A  

      Study group  :  30 in each group i.e

 IPI- Immediately placed implants 

 EPI- Early placed implants 

 DPI- Delayed placed implants

Justification for the sample size chosen :

The sample size has been calculated using the formula proposed by Wang and Fan for pilot/experimental studies.

n ≥ C*2* �’�²/�’’²

Where:

V: Variability between the groups = 23.53%= 0.24

C= Constant at 80% power of study and 95%

CI= 7.84

d= effect size = 15% =0.15

Putting in the formulae

n ≥ 7.84*2*(0.24)2 )/(0.15)2

= 27.35

~30 in ALL treatment groups.

 Assuming a data loss of 10% and rounding off to nearest multiple of 10, the proposed minimum sample size is 30 patients in each treatment group.

iv.) Detailed methodology:

The study shall be carried out on patients having a need of implant placement in the maxillary anterior region attending the Outpatient Department of Prosthodontics, Crown & Bridge and Implantology in Sardar Patel Post Graduate Institute of Dental and Medical Sciences. With permission from Ethical Committee, a written informed consent will be obtained from each patient after explaining the nature and outcome of procedure and the possible consequences and complications, Patients will be selected irrespective of caste, sex. religion or socio-economic status.

The patients will be divided into three groups of thirty each on the basis of -

IMMEDIATE, EARLY or DELAYED placement of implants.

Follwing radiographic assessments and pre-operative investigation will be done.

A.    Radiographic Assessment

                  * CBCT

* Intra oral periapical radiograph / RVG

B. Preoperative Investigation

* Haemogram

* Bleeding time, Clotting time, Prothrombin time (INR)

* ELISA for HIV

* HBsAg

* Blood glucose level (HbAlc)

* Serum Calcium

*Vitamin D3

* Lipid profile

After thorough radiographical and clinical examination, the decision will be made whether an implant can be placed immediately, at an early stage or at delayed stage.

The patients will be divided into three groups of thirty each on the basis of immediate, early or delayed placement of implants.

SURGICAL PHASE:

Cases for immediate implant placement will be selected which have straight root, good palatal bone and sagittal root position (SRP) class I and II according to the criteria proposed Kan J et al (2011). Cases having buccal defects, severe periodontitis, converging roots and requiring GBR will be excluded from this study and any periapical pathology.

The standardised aseptic surgical process rules will be followed for the insertion of the dental implants. The site will be anesthetized with 2% lignocaine and 1:80,000 adrenaline

In these patients, atraumatic extraction will be carried out with minimal mucoperiosteal flap elevation. With the help of preoperative CBCT, the size of the implant to be placed will be determined. Osteotomy will be initiated with a pilot drill following the recommended sequence of drills. The palatal bone will be engaged so that the implant achieves its initial primary stability and future prosthesis is in centre buccolingually and mesiodistally. The osteotomy will always be extended beyond the apex and the socket of the extracted teeth, a minimum of 3 mm beyond it.  The implant will be placed at 2mm below the adjacent tooth CEJ.

Similarly, for early placement, after extraction, the implant will be placed within 4-8 weeks using the above-mentioned surgical protocol.

The delayed implant placement will be done after three months of extraction. 

The standardized aseptic surgical process rules will be followed for the insertion of the dental implants. The site will be anesthetized with 2% lignocaine and 1:80,000 adrenaline before the insertion. The procedure involves releasing incision that will be used to raise a full-thickness flap exposing the crest and vestibular limit of the bone. Pilot drilling will be done upto the  length of the implant. While the osteotomy site is being prepared by incremental drilling, a large quantity of cold saline solution will be continuously irrigated. A paralleling pin will be placed followed by RVG in order to check its angulation Then implant will be placed at an equicrestal level using an extender and torque ratchet. After that cover screw will be placed. Primary closure will be done using 3-0 suture.

Resonance Frequency Measurement:

Resonance Frequency Analysis will be done by taking the Implant Stability Quotient (ISQ) in all three groups at baseline and after six months post-operatively. The analysis of RFA will be made using Ostell Mentor apparatus. For the initial reading of RFA the Smartpegs will be mounted on the implants after placement. The measurement will be taken in mesiodistal direction followed by buccolingual direction. Each value will be repeated four times, and the average value will be taken. The results will be expressed in implant stability quotient (ISQ). Postoperatively, the implant site will be inspected after six months of implant placement and ISQ value will be recorded again using the same method after removing the cover screw. The implant site will be checked for any visual signs of inflammation, mobility, gingival margin location, attachment level and gingival width. An orthopantomogram will be assessed for any signs of radiolucency around the implant.

 7. STATISTICAL ANALYSIS