Influence of Inter-Radicular Septal Bone Quantity in Primary Stability of Immediate Molar Implants with Different Length and Diameter Placed in Mandibular Region. A Cone-Beam Computed Tomography-Based Simulated Implant Study

Abstract

Aim: The purpose of this in vitro study was to investigate the influence of length and width of implant on primary stability in immediate implants in mandibular first molar. Materials and Methods: The study was carried out on 40 cone-beam computed tomography scans selected with defined inclusion and exclusion criteria. According to the diameter and length of implants, they were divided into nine groups (G1 to G9). The virtual implants of different diameters and length were placed in mandibular first molar and measurements were done for peri-implant horizontal and vertical gap defect, peri-implant interradicular bone support and apical bone support for all the groups. Results: The study groups Diameter, (D-7 mm) showed least horizontal gap defect (Buccal-1.30 ± 0.56 mm, lingual-1.30 ± 0.56 mm, mesial-1.20 ± 0.51 mm, and distal-1.05 ± 0.59 mm) as compared to regular implant diameter (D-4.7) groups (Buccal-2.35 ± 0.483 mm, lingual-2.10 mm ± 0.44 mm, mesial-2.30 ± 0.64 mm, and distal-2.25 ± 0.43 mm). The unsupported Vertical implant gap defect at the coronal part of the socket was 2.80 mm ± 0.83 mm for all groups in both horizontal and vertical direction. The vertical peri-implant interradicular bone support showed increased bone support with increase in implant length (L). The buccal and lingual inter-radicular bone-support was least for Length (L-8.5 mm), moderate for L-11.5 mm, and highest for L-13.5 mm groups, respectively. The mesial inter-radicular bone support was least for G4G7, moderate for G1G2G5G8, and maximum for G3G6G9 groups. Similarly, the distal inter-radicular bone support was least for G4G7, moderate for G1G5G8, and maximum for G2G3G6G9 groups, respectively. There was no apical bone support in L-8.5 mm group as the tip of implant was 3.5–4 mm within the socket tip. Whereas, L-11.5 mm had decent (0.9–1 mm) and L-13.5 mm had Good (1.35–1.95 mm) apical bone support as the implant tip was beyond the socket tip. Conclusion: All the groups showed good interradicular bone support on buccal and lingual surfaces. Regular width implants with longer length showed satisfactory interradicular bone support on mesial and distal surfaces. Longer implants showed good apical bone support in all the four surfaces and hence good apical primary stability expected.

Cone-Beam Computed Tomography (CBCT)-Based Assessment of the Alveolar Bone Anatomy of the Maxillary and Mandibular Molars: Implication for Immediate Implant Placement

“…Most maxillary first molars are type A (IRB >6 mm), while 60% of second molars are type B (IRB = 3-6 mm) [ 13 ]. While in the mandible, most extractions sockets were type B in the first molar site and type C in the second molars [ 21 ]. In such cases, IRB is insufficient to place the implant with a standard size, and implant primary stability is compromised [ 22 ].…”

Evaluation of mandibular first molar teeth in the context of immediate implant placement using Cone Beam Computed Tomography

“…Therefore, clinicians' use of the immediate implant (IMI) procedure is increasing due to implant placement without waiting after extraction, the positive expectations for the maintenance of bone volume and aesthetics (4). Providing primary stability, which is a very important criterion in dental implant surgery (5), especially posterior regions, may present some limitations for clinicians (6). In the posterior mandible, the use of native bone on the apical side of the extraction socket, which is important for primary stability, can be restricted by the location of the inferior alveolar canal (IAC) and the concavity of the submandibular fossa (7).…”