The effect of diameter and length on the success rate of dental implant: Prospective clinical study

The problem of missing teeth and edentulous is worldwide. Replacing teeth by dental implant is a successful treatment option. Focus on these factors that enhance the overall success rate of is become important subject. The variation in dental implant geometry, designs and surface texture provided by the manufacturing companies is become important controlling factors on successful treatment. Objectives: Use variable diameter and length to calculate the success percent of dental implant. Materials and method: Prospective study involve (680) patients come department of dental implantology in Al-Ramadi city health center between (May 2007-May 2018). 870 easy implant® by French dental implants manufacturer, conical with internal hexagon are used to replace teeth in variety of length and diameter:Max. Central incisor 5×11.5, Max. lateral incisors 5×8.5, Max. canine 5×8.5, Max. 1st premolar 4.3×11, Max. 2nd premolar 4.3-8, Max. molars 5×7, Mand. central incisors 3.5×10, Mand. lateral incisor 3.5×10.5, Mand. canine 3.5×11.5, Mand. 1st premolar 3.5×8, Mand. 2nd premolar 3.4×8, Mand. molars 4.5×7. Results: The statistical results indicate that the higher survival rate was (95%) in the Anterior incisors area due standard diameter and length of dental implant. The mean difference is significant at 0.05 level (P<0.05). Conclusion: Use of standardized diameter, length of dental implant is one factors used to enhance the success rate of this treatment. *Correspondence to: Liqaa S Farhan, MSc, BDS, Maxillofacial surgery, College of Dentistry, University of Anbar, Iraq, E-mail: liqaa.shallal@gmail.com


Introduction
The problem of loss of teeth due to extensive caries and periodontal disease is worldwide. Replacement of missing teeth by endosseous implant engage wide use by many dentists other than use fixed bridge and removable denture [1]. Dental implant is that metal component that inserted surgically in jawbone to holed fixed bridge and crown and over dentures. It's act by dissipate force to surrounding bone. Such load affects the stability and survival rate of dental implant [2]. The success rate of dental implant is become very high nowadays due development of new designs, number and load characteristics. The main mechanical benefit from dental implant geometry to dissipate the applied load to peri-implant bone [3,4]. The high stress over the bone surrounding dental implant induced by improper transmission of load due to defect in prosthetic appliance, occlusion, dental implant design and also surgical procedures [5]. Other factors like nature of surrounding bone and dental implant materials. The distribution of dental implant in jaw is other factor that affect the stress transmitted over ossteointegrted implant [6]. The used of short dental implant in molar area due mechanical and anatomical limitation [7]. The high occlusal force over the molar teeth in comparison to anterior teeth make size of dental implant of important factor. High force of occlusion also affect the success of ostointegation [8]. Large size of dental implant in molar area affect the thickness of surrounding bone and finally the success of placement of dental implant placed in such high stress area and other problem related to operative skill [9]. Bone quality and height and location of vital anatomical structure in the jaw bones is also other factors to be considered [10]. Wide diameter dental implant is also used as successful replacement of fractured and non osteointegrated implant [11]. For such reason conical shaped threaded implant of various diameters and length has been developed to enhance the survival rate of dental implants [12].

Materials and method
Prospective study involve (680) patients come to Al-Ramadi health center in department of dental implantology between (May 2007-May 2108).820 easy implant® by franch dental implants manufacturer, conical with internal hexagon are used in variety length and diameter:Max. Central incisor 5×11. 5  paced and the flap replaced and suture using 3/0 black silk. The dental implant were left in load free period. After 4 months the dental implant were uncovered and gingiva former were placed. After 1-week transfer coping were placed and dental impression was taken by alginate. After 1 week the dental appliance were placed. After 1 year the patient were examined clinically, a criterion used for assessment of successful dental implantation are: No pain or tenderness, no mobility, no radiographical bone loss, no pus, no gingival bleeding and no infection. The crestal bone resorption was measured mesially and distally with caliber and the success rate was estimated.

Statistical analysis
The statistical analysis in below Tables 1-16 indicate the following (Figures 1-5).
The statistical analysis in Tables 14 and 15 and Figure 4 indicate that the highest mean value of the mean mesial and distal bone loss was in Posterior Mandibular area was (3.6000±.10000) in comparison with mean mesial and distal bone loss in Anterior Mandibular area (0.3200±.01000). The mean difference is significant at 0.05 level (P<0.05).
Farhan LS (2019) The effect of diameter and length on the success rate of dental implant: Prospective clinical study

Discussion
Our study was done to estimate the success rate of dental implant using different diameter and length of dental implant placed in different positions. The statistical results of study in Tables 8 and 9 and Figure 2 show survival rate of dental implant in different treated position. The high survival rate of dental implant was in maxillary incisor area (95%) due to use standard size with wide and long dental implant and lower stress area [13,14]. This is also because the large size of dental implant increases the surface area of contact between bone and dental implant and minimize the stress distributed to this area and increase the success of osteointegration. While the lowest survival rate of dental implant was in mandibular molar area (55%) in comparison with other site this due to use of wide size and short for reason related to anatomy and high stress. Statistical result in Tables 1 and 2 and Figure 1 indicate that the higher mean value of diameter of dental implant was in maxillary anterior area (5.000±0.0000). While the lowest mean value was (3.5000±0.000) in anterior mandible. The mean difference is significant at 0.05 level (P<0.05). While the statistical results in Tables 4 and 5 and Figure 2 indicate that the highest mean value of length of dental implant was (10.6667±0.76376) in Anterior Mandible. While the lowest mean value of length of dental implant was in posterior mandible was (7.6667±0.57735) (P>0.05) non-significant at 0.05 level. Tables 14 and 15 Figure 5 indicate that the highest mean value of mesial and distal marginal loss was (3.6000±0.10000) in mandibular molar area in comparison with other sites (0.1233±0.00577). The mean difference is significant at 0.05 level (P<0.05) [15,16]. Use of short and large diameter dental implant is instead of bone grafting to avoid the danger of damage to the inferior alveolar nerve and canal and effect of high occlusal load over scares bone and hinder successful ostointegration [17,18]. The difficulty in placing such size is also other factor to be considered in the failure rate of dental implant in these area [19,20]. This is consistent to study conducted Renoaurd who indicate that the failure rate of dental implant increases with short and large diameter, it led to narrow thickness of surrounding bone and also poor skill of dentist [21]. The failure rate of dental implant is increase also due to other factor such as smoking, systemic disease, periodontal condition, surface texture, dental appliance and distribution dental implant through jaw [22]. Studies by Misch indicate that placement of short dental implant<10 mm in posterior molar area associated with high failure rate about 85% after placement of dental appliance [23,24]. But its use has added advantage it minimizes the time required for grating procedures, cost and avoid the postoperative surgical complications and morbidity [25]. Short dental implant in (molar) has complications related to initial stability due less surface contact with bone and interm of stress distribution which hinder successful ossteointgration [26].

Conclusion
Variation in Dental implant geometry provided by many companies to overcome the limitation in use of dental implant in certain area. Large size dental implant increases the area of contact with bone and better distribution of occlusal load which required for osteointergation. This make considerable increases in overall success rate.