Fig. 5. Anti-RANKL and anti-RANKL+miR-146a treatments decreased gingival mRNA expression of TNF-α and RANKL with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Gingival tissues around ligatured implants and non-ligation implants were excised and processed for RT-qPCR analysis to determine mRNA level of TNF-α of WT mice (a) and TLR2/4 KO mice (b) (mean ± SD, n = ...
Fig. 4. Anti-RANKL and anti-RANKL+miR-146a treatments decreased the inflammatory cell infiltration of the implant gingival tissues with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. HE staining of the gingival tissue around implants were performed in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL ...
Fig. 3. Anti-RANKL and anti-RANKL+miR-146a treatments decreased TRAP-positive cell quantities with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. TRAP-positive cells (red color) with 3 or more nuclei were considered osteoclasts and were shown in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL antibo...
Fig. 2. Anti-RANKL and anti-RANKL+miR-146a treatments decreased ligature-induced bone resorption with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Buccal side images of the defleshed skulls were taken of the control (non-ligation) group, ligation (non-treatment) group, ligation with anti-RANKL antibody (ligation+AR) treatment group, and ligation with anti-RANKL a...
Fig. 1. Mouse model of ligature-induced experimental peri-implantitis. (a) Tooth extraction: left maxillary first and second molars extracted at 4 weeks old and the tooth extraction socket healed well with smooth gingiva surface after 6 weeks post-extraction. Implant placement: implant was put in alveolar bone without flap elevation. Ligature placement: at 4 weeks post-implant, 7-0 ligatur...
 Total implantsLostLooseOsseointegratedSuccess rate (%)SR P valueWild type group60654981.670.595TLR2/4 KO group60445286.67Table 1 Success rate (SR) of osseointegrated implants 4 weeks after implant placement
Pan, K., Hu, Y., Wang, Y. et al. RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling. Int J Implant Dent 6, 15 (2020). https://doi.org/10.1186/s40729-020-00210-0
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Received: 24 September 2019
Accepted: 12 March 2020
Published: 15 April 2020
DOI: https://doi.org/10.1186/s40729-020-00210-0
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material...
The numerical data of all graphs.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Not applicable
Not applicable
Keqing Pan, Yang Hu, Yufeng Wang, Hao Li, Michele Patel, Danyang Wang, Zuomin Wang, and Xiaozhe Han certify that they do not have any commercial or associate interest that represents a conflict of interest in connection with the manuscript. The submitted work was not carried out in the presence of any personal, professional, or financial relationships that could pot...
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KP contributed to the conception and design; contributed to the acquisition, analysis, and interpretation of data; and drafted the manuscript. YH contributed to the conception and design, contributed to the acquisition, anal...
Department of Stomatology, The Affiliated Hospital of Qingdao University, College of Stomatology, Qingdao University, Qingdao, 266003, Shandong, China
Keqing Pan
Department of Immunology and Infectious Diseases, The Forsyth Institute, 245 First Street, Cambridge, MA, 02142, USA
Keqing Pan, Yang Hu, Yufeng Wang, Hao Li, Michele Patel & Xiaozhe Han
Department of Oral Medicine, Ninth People...
This study was supported by NIH NIDCR R01DE025255 and the Forsyth Institute FPILOT36 to X Han and the Forsyth Institute FPILOT52 to Y Hu.
Tu S, Zhong D, Xie W, Huang W, Jiang Y, Li Y. Role of toll-like receptor signaling in the pathogenesis of graft-versus-host diseases. Int J Mol Sci. 2016;17(8).
Gaddis DE, Michalek SM, Katz J. TLR4 signaling via MyD88 and TRIF differentially shape the CD4+ T cell response to Porphyromonas gingivalis hemagglutinin B. J Immunol. 2011;186(10):5772–83.
Zhang P, Liu J, Xu Q, et al. TLR2-dependent m...
Kawai T, Akira S. Toll-like receptors and their crosstalk with other innate receptors in infection and immunity. Immunity. 2011;34(5):637–50.
Song GG, Kim JH, Lee YH. Toll-like receptor (TLR) and matrix metalloproteinase (MMP) polymorphisms and periodontitis susceptibility: a meta-analysis. Mol Biol Rep. 2013;40(8):5129–41.
Lin J, Bi L, Yu X, et al. Porphyromonas gingivalis exacerbates ligat...
Shuto T, Wachi T, Shinohara Y, Nikawa H, Makihira S. Increase in receptor activator of nuclear factor kappaB ligand/osteoprotegerin ratio in peri-implant gingiva exposed to Porphyromonas gingivalis lipopolysaccharide. J Dent Sci. 2016;11(1):8–16.
O'Connell MB. Prescription drug therapies for prevention and treatment of postmenopausal osteoporosis. J Manag Care Pharm. 2006;12(6 Suppl A):S10-19; ...
Bertin TJC, Thivichon-Prince B, LeBlanc ARH, Caldwell MW, Viriot L. Current perspectives on tooth implantation, attachment, and replacement in amniota. Front Physiol. 2018;9:1630.
Schminke B, Vom Orde F, Gruber R, Schliephake H, Burgers R, Miosge N. The pathology of bone tissue during peri-implantitis. J Dent Res. 2015;94(2):354–61.
Mombelli A, Muller N, Cionca N. The epidemiology of peri-impl...
Receptor activator of nuclear factor-kappa Î’ ligand
Toll-like receptor
Wild type
MicroRNA 146a
Micro-computed tomography
Real-time quantitative PCR
Tumor necrosis factor alpha
Osteoprotegerin
Lipopolysaccharides
Hematoxylin and eosin
Tartrate-resistant acid phosphatase
Presented in the main paper
In summary, the present study suggests that anti-inflammatory miR-146a enhance anti-RANKL-induced inhibition of peri-implant bone resorption through the regulation of TLR2/4 signaling and inhibition of TNF-α expression. Combination of regimens antagonizing both osteoclastogenesis and inflammation may become a more effective strategy to ameliorate peri-implantitis bone loss.
According to the previous studies, miR-146a was regulated by NF-κB and blockade of miR-146a could decrease TLR4 and NF-κB in human cells [41, 42], suggesting that miR-146a is involved in TLR/NF-κB signaling pathway. Our recent study showed that miR-146a inhibited inflammatory cytokine secretion in B cells after challenged with P. gingivalis LPS and decreased bone resorption in experimental peri...
Our present study showed that anti-RANKL antibody can significantly inhibit the bone loss in peri-implantitis and additional miR-146a treatment will enhance this inhibition through its anti-inflammation effects via TLR2/4 signaling. This is the first report in a murine model of peri-implantitis to demonstrate that anti-RANKL antibody and miR-146a together can significantly reduce bone resorption a...
In both WT mice and TLR2/4 KO mice, a significantly higher number of inflammatory cells were found infiltrating around the peri-implant tissues in the ligation group compared with the non-ligation group (Fig. 4a–c). However, the number of inflammatory cells in tissues of the ligation group was not significantly changed when treated with anti-RANKL antibody alone in both WT and TLR2/4 KO mice com...
In our ligature-induced experimental peri-implantitis mouse model, teeth extraction, implant placement, ligation placement, and gingival injection will be performed in a 12-week process (Fig. 1). 86.67% (52 out of 60) of implants in TLR2/4 KO mice achieved osteointegration (no mobility when touched by needles, no obvious bleeding upon probing) after being placed for 4 weeks, which has no signifi...
Palatal gingival tissues were isolated from around ligatured implants and were homogenized in lysis buffer using a tissue homogenizer. Total RNA was extracted using PureLink® RNA Mini Kit (Ambion). cDNA was synthesized using the SuperScript III Reversed Transcriptase kit (Invitrogen) according to the manufacturer’s protocol. The mRNA expression of TNF-α and RANKL in gingival was determined by ...
The ligations were maintained for 2 weeks, and after which the mice were euthanized by CO2 inhalation and the maxilla were harvested. The gingival tissues of half group of mice were isolated and collected for mRNA expression study. The skulls left were defleshed by beetles for 1 week. Briefly, in beetle’s chamber, freshly dissected skull was put in a paper cup with 0.5 cm diameter holes at...
Wild-type (WT) C57BL/6 and TLR2 KO and TLR4 KO mice in C57/BL6 background were purchased from the Jackson Laboratory (Bar Harbor, ME). TLR2 and TLR4 double KO mice (TLR2/4 KO) were crossbreed from TLR2 KO and TLR4 KO mice and confirmed by genotyping. All the animal-associated protocols were reviewed and approved (#17-022) by the Institutional Animal Care and Use Committee of the Forsyth Institute....
Toll-like receptors (TLR) are a family of well-characterized pattern recognition receptors (PRRs) and play an important role in the induction of pro-inflammatory cytokines by recognizing the signature molecules of the host innate immunity [25,26,27]. Our previous studies showed that TLR2 are associated with implant bone loss in a mouse model of peri-implantitis [5] and TLR4 is essential for period...
Dental implant has become a preferable choice to restore the missing tooth in the past few decades for functional and esthetic purposes [1]. However, peri-implantitis has become prevalent accompanying the exponential growth of dental implant procedures [2, 3]. Peri-implantitis is indicated by infection of implant surrounding soft tissues and bone loss, resulting in implant failure eventually [4,5,...
This study suggests that anti-inflammatory miR-146a enhance anti-RANKL-induced inhibition of peri-implant bone resorption through the regulation of TLR2/4 signaling and inhibition of TNF-α expression.
The present study was to determine the effect of local anti-RANKL antibody administration in the presence or absence of microRNA-146a on ligature-induced peri-implant bone resorption, and the potential role of TLR2/4 signaling in such effect.
Titanium implants were placed in the left maxilla alveolar bone 6 weeks after extraction of first and second molars in C57/BL6 wild-type (WT) and TLR2−/...
Fig. 5. Anti-RANKL and anti-RANKL+miR-146a treatments decreased gingival mRNA expression of TNF-α and RANKL with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Gingival tissues around ligatured implants and non-ligation implants were excised and processed for RT-qPCR analysis to determine mRNA level of TNF-α of WT mice (a) and TLR2/4 KO mice (b) (mean ± SD, n = ...
Fig. 4. Anti-RANKL and anti-RANKL+miR-146a treatments decreased the inflammatory cell infiltration of the implant gingival tissues with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. HE staining of the gingival tissue around implants were performed in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL ...
Fig. 3. Anti-RANKL and anti-RANKL+miR-146a treatments decreased TRAP-positive cell quantities with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. TRAP-positive cells (red color) with 3 or more nuclei were considered osteoclasts and were shown in the control group, ligation group, ligation with anti-RANKL antibody treatment group, and ligation with anti-RANKL antibo...
Fig. 2. Anti-RANKL and anti-RANKL+miR-146a treatments decreased ligature-induced bone resorption with different patterns in experimental peri-implantitis of WT and TLR2/4 KO mice. Buccal side images of the defleshed skulls were taken of the control (non-ligation) group, ligation (non-treatment) group, ligation with anti-RANKL antibody (ligation+AR) treatment group, and ligation with anti-RANKL a...
Fig. 1. Mouse model of ligature-induced experimental peri-implantitis. (a) Tooth extraction: left maxillary first and second molars extracted at 4 weeks old and the tooth extraction socket healed well with smooth gingiva surface after 6 weeks post-extraction. Implant placement: implant was put in alveolar bone without flap elevation. Ligature placement: at 4 weeks post-implant, 7-0 ligatur...
 Total implantsLostLooseOsseointegratedSuccess rate (%)SR P valueWild type group60654981.670.595TLR2/4 KO group60445286.67Table 1 Success rate (SR) of osseointegrated implants 4 weeks after implant placement
Pan, K., Hu, Y., Wang, Y. et al. RANKL blockade alleviates peri-implant bone loss and is enhanced by anti-inflammatory microRNA-146a through TLR2/4 signaling. Int J Implant Dent 6, 15 (2020). https://doi.org/10.1186/s40729-020-00210-0
Download citation
Received: 24 September 2019
Accepted: 12 March 2020
Published: 15 April 2020
DOI: https://doi.org/10.1186/s40729-020-00210-0
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material...
The numerical data of all graphs.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Not applicable
Not applicable
Keqing Pan, Yang Hu, Yufeng Wang, Hao Li, Michele Patel, Danyang Wang, Zuomin Wang, and Xiaozhe Han certify that they do not have any commercial or associate interest that represents a conflict of interest in connection with the manuscript. The submitted work was not carried out in the presence of any personal, professional, or financial relationships that could pot...
You can also search for this author in PubMed Google Scholar
You can also search for this author in PubMed Google Scholar
KP contributed to the conception and design; contributed to the acquisition, analysis, and interpretation of data; and drafted the manuscript. YH contributed to the conception and design, contributed to the acquisition, analysis, and interpretation of data; drafted the manu...
Department of Stomatology, The Affiliated Hospital of Qingdao University, College of Stomatology, Qingdao University, Qingdao, 266003, Shandong, China
Keqing Pan
Department of Immunology and Infectious Diseases, The Forsyth Institute, 245 First Street, Cambridge, MA, 02142, USA
Keqing Pan, Yang Hu, Yufeng Wang, Hao Li, Michele Patel & Xiaozhe Han
Department of Oral Medicine, Ninth People...
This study was supported by NIH NIDCR R01DE025255 and the Forsyth Institute FPILOT36 to X Han and the Forsyth Institute FPILOT52 to Y Hu.
Tu S, Zhong D, Xie W, Huang W, Jiang Y, Li Y. Role of toll-like receptor signaling in the pathogenesis of graft-versus-host diseases. Int J Mol Sci. 2016;17(8).
Gaddis DE, Michalek SM, Katz J. TLR4 signaling via MyD88 and TRIF differentially shape the CD4+ T cell response to Porphyromonas gingivalis hemagglutinin B. J Immunol. 2011;186(10):5772–83.
Zhang P, Liu J, Xu Q, et al. TLR2-dependent m...
Kawai T, Akira S. Toll-like receptors and their crosstalk with other innate receptors in infection and immunity. Immunity. 2011;34(5):637–50.
Song GG, Kim JH, Lee YH. Toll-like receptor (TLR) and matrix metalloproteinase (MMP) polymorphisms and periodontitis susceptibility: a meta-analysis. Mol Biol Rep. 2013;40(8):5129–41.
Lin J, Bi L, Yu X, et al. Porphyromonas gingivalis exacerbates ligat...
Shuto T, Wachi T, Shinohara Y, Nikawa H, Makihira S. Increase in receptor activator of nuclear factor kappaB ligand/osteoprotegerin ratio in peri-implant gingiva exposed to Porphyromonas gingivalis lipopolysaccharide. J Dent Sci. 2016;11(1):8–16.
O'Connell MB. Prescription drug therapies for prevention and treatment of postmenopausal osteoporosis. J Manag Care Pharm. 2006;12(6 Suppl A):S10-19; ...
Bertin TJC, Thivichon-Prince B, LeBlanc ARH, Caldwell MW, Viriot L. Current perspectives on tooth implantation, attachment, and replacement in amniota. Front Physiol. 2018;9:1630.
Schminke B, Vom Orde F, Gruber R, Schliephake H, Burgers R, Miosge N. The pathology of bone tissue during peri-implantitis. J Dent Res. 2015;94(2):354–61.
Mombelli A, Muller N, Cionca N. The epidemiology of peri-impl...
Receptor activator of nuclear factor-kappa Î’ ligand
Toll-like receptor
Wild type
MicroRNA 146a
Micro-computed tomography
Real-time quantitative PCR
Tumor necrosis factor alpha
Osteoprotegerin
Lipopolysaccharides
Hematoxylin and eosin
Tartrate-resistant acid phosphatase
Presented in the main paper
In summary, the present study suggests that anti-inflammatory miR-146a enhance anti-RANKL-induced inhibition of peri-implant bone resorption through the regulation of TLR2/4 signaling and inhibition of TNF-α expression. Combination of regimens antagonizing both osteoclastogenesis and inflammation may become a more effective strategy to ameliorate peri-implantitis bone loss.
According to the previous studies, miR-146a was regulated by NF-κB and blockade of miR-146a could decrease TLR4 and NF-κB in human cells [41, 42], suggesting that miR-146a is involved in TLR/NF-κB signaling pathway. Our recent study showed that miR-146a inhibited inflammatory cytokine secretion in B cells after challenged with P. gingivalis LPS and decreased bone resorption in experimental peri...
Our present study showed that anti-RANKL antibody can significantly inhibit the bone loss in peri-implantitis and additional miR-146a treatment will enhance this inhibition through its anti-inflammation effects via TLR2/4 signaling. This is the first report in a murine model of peri-implantitis to demonstrate that anti-RANKL antibody and miR-146a together can significantly reduce bone resorption a...
In both WT mice and TLR2/4 KO mice, a significantly higher number of inflammatory cells were found infiltrating around the peri-implant tissues in the ligation group compared with the non-ligation group (Fig. 4a–c). However, the number of inflammatory cells in tissues of the ligation group was not significantly changed when treated with anti-RANKL antibody alone in both WT and TLR2/4 KO mice com...
In our ligature-induced experimental peri-implantitis mouse model, teeth extraction, implant placement, ligation placement, and gingival injection will be performed in a 12-week process (Fig. 1). 86.67% (52 out of 60) of implants in TLR2/4 KO mice achieved osteointegration (no mobility when touched by needles, no obvious bleeding upon probing) after being placed for 4 weeks, which has no signifi...
Palatal gingival tissues were isolated from around ligatured implants and were homogenized in lysis buffer using a tissue homogenizer. Total RNA was extracted using PureLink® RNA Mini Kit (Ambion). cDNA was synthesized using the SuperScript III Reversed Transcriptase kit (Invitrogen) according to the manufacturer’s protocol. The mRNA expression of TNF-α and RANKL in gingival was determined by ...
The ligations were maintained for 2 weeks, and after which the mice were euthanized by CO2 inhalation and the maxilla were harvested. The gingival tissues of half group of mice were isolated and collected for mRNA expression study. The skulls left were defleshed by beetles for 1 week. Briefly, in beetle’s chamber, freshly dissected skull was put in a paper cup with 0.5 cm diameter holes at...
Wild-type (WT) C57BL/6 and TLR2 KO and TLR4 KO mice in C57/BL6 background were purchased from the Jackson Laboratory (Bar Harbor, ME). TLR2 and TLR4 double KO mice (TLR2/4 KO) were crossbreed from TLR2 KO and TLR4 KO mice and confirmed by genotyping. All the animal-associated protocols were reviewed and approved (#17-022) by the Institutional Animal Care and Use Committee of the Forsyth Institute....
Toll-like receptors (TLR) are a family of well-characterized pattern recognition receptors (PRRs) and play an important role in the induction of pro-inflammatory cytokines by recognizing the signature molecules of the host innate immunity [25,26,27]. Our previous studies showed that TLR2 are associated with implant bone loss in a mouse model of peri-implantitis [5] and TLR4 is essential for period...
Dental implant has become a preferable choice to restore the missing tooth in the past few decades for functional and esthetic purposes [1]. However, peri-implantitis has become prevalent accompanying the exponential growth of dental implant procedures [2, 3]. Peri-implantitis is indicated by infection of implant surrounding soft tissues and bone loss, resulting in implant failure eventually [4,5,...
This study suggests that anti-inflammatory miR-146a enhance anti-RANKL-induced inhibition of peri-implant bone resorption through the regulation of TLR2/4 signaling and inhibition of TNF-α expression.
The present study was to determine the effect of local anti-RANKL antibody administration in the presence or absence of microRNA-146a on ligature-induced peri-implant bone resorption, and the potential role of TLR2/4 signaling in such effect.
Titanium implants were placed in the left maxilla alveolar bone 6 weeks after extraction of first and second molars in C57/BL6 wild-type (WT) and TLR2−/...
Fig. 3. Example of another case involved in the study. a Preoperative view –premolars and molars are missing in left mandible. b Preoperative CT scan. The width of the ridge was around 4 mm. c Baseline periapical radiograph. Four narrow diameter implants were placed to restore the area. d Buccal view of the final full-contour zirconia restoration. e Periapical radiograph at 1 year after loa...
Fig. 2. Case 1: Example of one case involved in the study. a Preoperative view of a partial edentulism in posterior mandible. b Preoperative CT scan. The width of the ridge was 4 mm. c Four narrow diameter implants were placed and left to a nonsubmerged healing. d Baseline periapical radiograph. e Buccal vieew of the final metal ceramic restoration. f Periapical radiograph at 1 year after loa...
Fig. 1. Characteristics of the implants used in the study: a external macro-design of JDIcon Ultra S, 2.75 mm diameter implant and b external macro-design of JDEvolution S, 3.25 mm diameter implant
Fig. 1. Characteristics of the implants used in the study: a external macro-design of JDIcon Ultra S, 2.75 mm diameter implant and b external macro-design of JDEvolution S, 3.25 mm diameter i...
Diameter 2.75Â mm
Â
 Follow-up
Mean bone level changes (mm) (n = 69)
0–6 months (95% CI) (n = 67)
0–12 months (95% CI) (n = 67)
...
Follow-up
Mean bone level (mm) (n = 124)
Time
0–6 months (95% CI) (n = 121)
0–12 months (95% CI) (n = 121)
...
Length (mm)
8
18 (14.5%)
10
56 (45.2%)
11.5
...
Number of patients
42
Males (%)
18 (42.9%)
Females (%)
24 (57.1%)
...
Grandi, T., Svezia, L. & Grandi, G. Narrow implants (2.75 and 3.25Â mm diameter) supporting a fixed splinted prostheses in posterior regions of mandible: one-year results from a prospective cohort study.
Int J Implant Dent 3, 43 (2017). https://doi.org/10.1186/s40729-017-0102-6
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Received: 23 March 2017
Accepted: 29 August 2017
Published: 08 September 2017
...
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were...
Tommaso Grandi serves as a consultant for JDentalCare. Luigi Svezia and Giovanni Grandi declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Private practice, Via Contrada 323, 41126, Modena, Italy
Tommaso Grandi & Luigi Svezia
Department of Obstetrics, Gynecology and Pediatrics, University of Modena and Reggio Emilia, Modena, Italy
Giovanni Grandi
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Esposito M, Grusovin MG, Maghaireh H, Worthington HV. Interventions for replacing missing teeth: different times for loading dental implants (Review). Cochrane Database Syst Rev. 2013;(3):CD003878. https://doi.org/10.1002/14651858.CD003878.pub5.
Esposito M, Grusovin MG, Felice P, Karatzopoulos G, Worthington HV, Coulthard P. The efficacy of horizontal and vertical bone augmentation procedures for...
Within the limits of this prospective cohort study, narrow-diameter implants (2.75 to 3.25Â mm) can be successfully used as a minimally invasive alternative to horizontal bone augmentation in posterior mandible up to 1Â year of function. This outcome could be related to the fact that these implants have been all splinted to other implants by a fixed prosthesis. These preliminary results must be co...
On the one hand, due to the small sample size of this study and moreover, the short follow-up (only 1Â year after loading), it would be hazardous to conclude that the placement of NDIs to support fixed prostheses in posterior mandible is a predictable treatment modality. In order to draw more reliable conclusions, we need to wait for longer follow-ups, since it may be possible that after several y...
Dental implants with a reduced diameter are commonly used where bone width is narrow or in cases of restricted mesiodistal anatomy such as laterally maxillary and mandibular incisors. They could also be a viable alternative to bone augmentation especially in challenging situations such as the posterior regions of the mandible. While it has been shown that it is possible to horizontally augment bon...
The radiographic data are summarized in Tables 3 and 4. The group lost statistically significant marginal peri-implant bone at 6 months (−0.20; 95% C −0.14: −0.26, pÂ
Forty-eight patients were screened for eligibility, but six subjects were not included for the following reasons: five patients (10.4%) were hesitant to receive implant treatment, and one patient (2.1%) was treated with intravenous amino-bisphosphonates. Forty-two patients were then considered eligible and were consecutively enrolled in the study. All patients were treated according to the allocat...
Primary outcome measures were as follows:
Implant failure: evaluated as implant mobility and removal of stable implants dictated by progressive marginal bone loss or infection. The stability of each implant was measured manually by tightening the abutment screw with a wrench delivering a torque of 20Â Ncm. Implant stability assessment was performed at delivery of definitive crowns (3Â months afte...
The present prospective study was conducted at a private practice (Tommaso Grandi, Modena) in Italy between October 2014 and January 2016.
Any patient with partial edentulism in posterior regions of mandible (premolar/molar areas), requiring one multiple tooth implant-supported restoration (2-, 3-, or 4-unit bridge), having a residual bone height of at least 8Â mm and a thickness of at least 4Â m...
The aim of this cohort study was to evaluate the outcome of narrow-diameter implants (2.75 and 3.25 mm diameter) used as definitive implants in patients with insufficient bone ridge thickness for placing standard-diameter implants in posterior regions of the mandible. The present study reports the clinical outcome up to 1 year after loading. It is planned to follow up this patients’ cohort to ...
Historically, implants have been used and documented mainly with diameters between 3.7 and 4.3Â mm. Employing these diameters for numerous indications, scientifically substantiated treatment protocols with excellent long-term results have been established [1]. One disadvantage of a standard-diameter implant is the fact that, in clinical use, the available horizontal crestal dimensions of the alveo...
Can multiple splinted narrow-diameter implants be used as definitive implants in patients with insufficient bone ridge thickness in posterior regions of the mandible? With this aim, we evaluated their outcomes in this set up to 1Â year after loading.
Forty-two patients with a mean age of 61.3 years old (range 49–73) in need of fixed prosthetic implant-supported rehabilitations in the posterior...
Â
Figure 3. Example of another case involved in the study. a Preoperative view –premolars and molars are missing in left mandible. b Preoperative CT scan. The width of the ridge was around 4 mm. c Baseline periapical radiograph. Four narrow diameter implants were placed to restore the area. d Buccal view of the final full-contour zirconia restoration. e Periapical radiograph at 1Â...
Â
Figure 2. Case 1: Example of one case involved in the study. a Preoperative view of a partial edentulism in posterior mandible. b Preoperative CT scan. The width of the ridge was 4 mm. c Four narrow diameter implants were placed and left to a nonsubmerged healing. d Baseline periapical radiograph. e Buccal vieew of the final metal ceramic restoration. f Periapical radiograph at ...
Diameter 2.75Â mm
Â
 Follow-up
Mean bone level changes (mm) (n = 69)
0–6 months (95% CI) (n = 67)
0–12 months (95% CI) (n = 67)
p inter-groups
 Baseline
0.02 ± 0.07
−0.18 (−0.09; −0.27)
−0.47 (−0.27; −0.67)
p = 0.786
 6 months
0.20 ± 0.12
p intra-group
 12 months
0.49 ± 0.30
pÂ
Length (mm)
8
18 (14.5%)
10
56 (45.2%)
11.5
43 (34.7%)
13
7 (5.6%)
Diameter (mm)
2.75
69 (55.6%)
3.25
55 (44.4%)
Insertion torque (Ncm)
30
21 (16.9%)
35
16 (12.9%)
40
10 (8.1%)
45
11 (8.9%)
50
32 (25.8%)
55
7 (5.6%)
60
16 (12.9%)
65
5 (4.1%)
70
6 (4.8%)
Number of patients
42
Males (%)
18 (42.9%)
Females (%)
24 (57.1%)
Mean age at insertion (range)
62.6 (49–73)
Smokers (less than 10 cigarettes/die)
12 (28.6%)
Diseases in history
 Controlled diabetes type 2
11 (26.2%)
 Hypertension
19 (45.2%)
Site of insertion
 Premolar
81 (65.3%)
 Molar
43 (34.7%)
Opposite dentition
...
Â
Figure 1. Characteristics of the implants used in the study: a external macro-design of JDIcon Ultra S, 2.75 mm diameter implant and b external macro-design of JDEvolution S, 3.25 mm diameter implant
References
Esposito M, Grusovin MG, Maghaireh H, Worthington HV. Interventions for replacing missing teeth: different times for loading dental implants (Review). Cochrane Database Syst Rev. 2013;(3):CD003878. https://doi.org/10.1002/14651858.CD003878.pub5.
Esposito M, Grusovin MG, Felice P, Karatzopoulos G, Worthington HV, Coulthard P. The efficacy of horizontal and vertical bone augmenta...
Klein et al., in a recent systematic review, reported that the survival rate of implants with a diameter of
Discussion
Dental implants with a reduced diameter are commonly used where bone width is narrow or in cases of restricted mesiodistal anatomy such as laterally maxillary and mandibular incisors. They could also be a viable alternative to bone augmentation especially in challenging situations such as the posterior regions of the mandible. While it has been shown that it is possible to horizo...
Results
Forty-eight patients were screened for eligibility, but six subjects were not included for the following reasons: five patients (10.4%) were hesitant to receive implant treatment, and one patient (2.1%) was treated with intravenous amino-bisphosphonates. Forty-two patients were then considered eligible and were consecutively enrolled in the study. All patients were treated according to ...
Secondary outcome measures were as follows:
Peri-implant marginal bone level changes: evaluated on intraoral radiographs taken with the paralleling technique at implant placement, 6Â months and 1Â year after loading. All measurements were taken by an independent assessor (LS). Radiographs were scanned, digitized in JPG format, converted to TIFF format with a 600Â dpi resolution, and stored in...
On the day of surgery, patients were treated under local anesthesia.
Full-thickness crestal flaps were elevated with a minimal extension to reduce patient discomfort. The implant sites were prepared according to the procedure recommended by the implant manufacturer (JDentalCare, Modena, Italy).
Tapered narrow-diameter implants titanium grade 5 (2.75 and 3.25 mm diameter, respectively, JDIcon Ult...
Methods
The present prospective study was conducted at a private practice (Tommaso Grandi, Modena) in Italy between October 2014 and January 2016.
Any patient with partial edentulism in posterior regions of mandible (premolar/molar areas), requiring one multiple tooth implant-supported restoration (2-, 3-, or 4-unit bridge), having a residual bone height of at least 8 mm and a thickness of at ...
Background
Historically, implants have been used and documented mainly with diameters between 3.7 and 4.3Â mm. Employing these diameters for numerous indications, scientifically substantiated treatment protocols with excellent long-term results have been established [1]. One disadvantage of a standard-diameter implant is the fact that, in clinical use, the available horizontal crestal dimension...
Narrow implants (2.75 and 3.25Â mm diameter) supporting a fixed splinted prostheses in posterior regions of mandible: one-year results from a prospective cohort study
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Abstract
Background
Can multiple splinted narrow-diameter implants be used as definitive implants in patients with insufficient bone ridge thickness in posterior regions of the mandible? With this aim, we evaluated their out...
Figure 20. Ridge of edentulous site
The outer walls of the alveolar ridge consist of cortical bone. The buccal bone plate is comparatively thinner than the lingual or palatal plate. The cortical plates enclose trabecular bone that consists of bony trabeculae and marrow. As a rule, the ridge of an edentulous site in the maxilla contains comparatively more trabecular bone than a site in the man...
Figure 19. Bone resorption forms alveolar ridge
The term alveolar ridge refers to the alveolar bone following loss of teeth. After a tooth is extracted, the alveolar process heals with formation of bone within the socket and external resorption or shrinkage of the bone, forming the alveolar ridge.Â
Figure 3. Alveolar ridge
The outcome of this resorption is most often a significant modification of the pre-extraction outline of the alveolar ridge, which may present a problem for later prosthetic reconstruction. For this reason, a knowledge of the healing events following tooth extraction is essential for appropriate prosthodontically driven implant treatment planning. This...