ORIGINAL PAPERs
Marcin Kozakiewicz
1, A–C, E, Piotr Hadrowicz
1, B–D, F,
Joanna M. Hadrowicz
1, B–D, F, Adam Gesing
2, A, CCan Torque Force During Dental Implant Placement
Combined with Bone Mineral Density
of Lumbar Spine Be Prediction Factors
for Crestal Bone Structure Alterations?
Czy moment siły przy wprowadzaniu wszczepu zębowego
w połączeniu z gęstością kości kręgosłupa lędźwiowego
może być czynnikiem przewidywania zmian struktury
brzegu kości wyrostka zębodołowego?
1 Department of Maxillofacial surgery, Medical University of Lodz, Łódź, Poland 2 Department of Oncological Endocrinology, Medical University of Lodz, Łódź, Poland
A – research concept and design; B – collection and/or assembly of data; C – data analysis and interpretation; D – writing the article; E – critical revision of the article; F – final approval of article
Abstract
Background. Torque force is the most common method of primary stability evaluation, but it is not sufficiently
precise.
Objectives. The aim of this study was to evaluate the influence of dental implant insertion torque and bone mineral
density of a lumbar spine on structure of the marginal bone in alveolar crest after functional loading.
Material and Methods. The examination included 107 patients in the age of 17–67 (45.53 ± 12.1). Dental
intra-oral X-rays were taken in standardized conditions: directly post implantation and control X-rays immediately post loading implants in following months: 3, 6, 9, 12, 18, 24. After implantation the manual wrench was used to measure torque force (T). The first four lumbar vertebrae (L1–L4) was the area of interest. BMD (g/cm2) was
performed by a DXA machine. The next phase was to geometrically align all radiographs. Two regions of interest were marked in the bone image (ROI1: in implant neck region, ROI2: in periapical region). The textural entropy parameter was analyzed as a factor that responds to the formation of mature trabecular bone. Then, the relation between torque force, BMD and entropy of microarchitecture of bone image was studied. Next, ANOVA and an analysis of regression were used.
Results. There is no relation between the torque force and the structure of alveolar bone surrounding neck of the
dental implants in every period of investigation (ANOVA p > 0.05). The marginal crestal bone structure is related to bone mineral density of first four Lumbar vertebrae i.e. in patients with higher L1–L4 BMD, entropy measured in intraoral radiographs lower (analysis of regression 00M: p < 0.05). Next, the process of osseointegration and bone remodeling after dental implant placement erase that relation (00M_load: p = 0.42; 03M_Load: p = 0.89; 06M_Load: p = 0.66; 09M_Load: p = 0.56; 12M_Load: p = 0.88). And finally, after 18 and 24 months of functional loading again nature of relation BMD to crestal bone around dental implant is expressed (18M_Load: p < 0.05; 24M_Load: p < 0.05).
Conclusions. The assessment of bone mineral density of lumbar vertebra could be useful parameter to achieve
a dental implant success. Based on our survey the insertion torque force is not a sufficient prediction factor for dental implant success (Dent. Med. Probl. 2014, 51, 4, 448–457).
Key words: dental implants, bone mineral density, torque force, entropy.
Dent. Med. Probl. 2014, 51, 4, 448–457
Osseointegration plays a key role in achieving the implant’s success. An evaluation process of the degree of advancement allows us to start prosthet-ic treatment and forecast for the future. Osseointe-gration is a direct structural and functional bond-ing allogenic material and the patient’s bone tis-sue [1]. This process consists of several phases: inflammatory immune response, induction of dif-ferentiation of bone cells, formation and matura-tion of new bone on titanic surface. Part of osseo-integration, continuous process, internal recon-struction of bone is called remodeling. It consists of resorption and apposition located at the same place and time. There are studies on animals, where torque over 100 Ncm has been histologically examined. They prove that high torque forces pro-moted an increase of the bone remodeling. They did not find peri-implant fibrosis [2]. Cell activa-tion (osteoclast, osteoblast) undergoes hormonal systemic regulation. Local bone remodeling is also initiated by mechanic stimuli as fracture, inflam-mation but implant placement as well [3, 4].
An estimate of implant stabilization lets us ob-tain the progression in ossteointegrate. The most common methods [5]:
– resistance measurement (in Ncm) during implant placement,
– RTG investigation.
– resonance Frequency Devices (Ostell IsQTM,
PeriotestTM).
Torque force is the easiest method of assess-ment and is available just after implantation. There are two main issues defined with measure-ment stability: primary and secondary stability. When implant is loaded immediately, secondary stability cannot occur. However, primary stability can be observed. It is the mechanical result of im-paction of titanium screw in bone tissue. It can be measured during implantation [6, 7]. The mean-ing of primary stability decreases gradually as sec-ondary stability increases during the progression of bone reconstruction (osseointegration). The moment when primary stability is finishing, but bone remodeling is not sufficient is the most dan-gerous and important. This point could cause mo-bility and looseness of implant. This usually takes place 3–4 months post implantation [5]. Long- -term postoperative care is also very important. At this time radiographs are very useful, especially to observe bone resorption around the neck of the implant. Primary stability depends on the quali-ty and quantiquali-ty of bone, shape, dimension, quali-type of surface of implant, the percentage of initial bone- -implant interface, the method of osteotomy
prep-Streszczenie
Wprowadzenie. Moment siły wprowadzenia wszczepu jest najczęstszą metodą oceny stabilizacji pierwotnej, lecz
okazał się niewystarczająco precyzyjny.
Cel pracy. Ocena wpływu momentu siły wprowadzenia wszczepu zębowego oraz gęstości mineralnej kości
lędźwiowe-go odcinka kręlędźwiowe-gosłupa na strukturę brzegu kości wyrostka zębodołowelędźwiowe-go po czynnościowym obciążeniu wszczepu.
Materiał i metody. W badaniu uczestniczyło 107 pacjentów obu płci w wieku 17–67 (45,53 ± 12,1). Pacjentom
wykonano wewnątrzustne standaryzowane zdjęcia zębowe: bezpośrednio po wszczepieniu, bezpośrednio po czyn-nościowym obciążeniu wszczepu oraz 3, 6, 9, 12, 18, 24 miesiące po czynczyn-nościowym obciążeniu wszczepu. Następnie z użyciem klucza dynamometrycznego zmierzono moment siły wprowadzenia wszczepu (T). Uzyskano wartości w zakresie 10–60 Ncm. Za densytometryczny, referencyjny obszar zainteresowania wybrano pierwsze cztery kręgi lędźwiowe (L1–L4). Gęstość mineralną kości – BMD (g/cm2) uzyskano dzięki badaniu dentystometrycznemu
(DXA). Kolejnym etapem było geometryczne wyrównanie zdjęć wewnątrzustnych. Oznaczono dwa obszary zain-teresowania na teksturze zdjęć wewnątrzustnych – ROI1: okolica szyjki wszczepu zębowego, ROI2: okolica przy-wierzchołkowa. Następnie obliczono entropię radiotekstury obrazu kostnego. Zbadano związek między momentem siły wprowadzenia wszczepu, gęstością mineralną kości lędźwiowego odcinka kręgosłupa a entropią mikroarchitek-tury kości wyrostka zębodołowego. Ocena statystyczna dotyczyła analizy wariancji i analizy regresji.
Wyniki. We wszystkich okresach badania nie wykazano statystycznie znamiennego związku pomiędzy
momen-tem siły wprowadzenia wszczepu zębowego a strukturą kości wyrostka zębodołowego otaczającej szyjkę wszczepu (ANOVA p > 0,05). struktura brzegu kości wyrostka zębodołowego jest powiązana z gęstością mineralną pierw-szych czterech kręgów lędźwiowych – dla pacjentów z większymi wartościami L1–L4 BMD entropia mierzona na zdjęciach wewnątrzustnych jest mniejsza (analiza regresji 00M: p < 0,05). Następnie ten związek zanika wskutek procesu osteointegracji oraz remodelingu kości po obciążeniu wszczepu zębowego (00M_load: p = 0,42; 03M_Load: p = 0,89; 06M_Load: p = 0,66; 09M_Load: p = 0,56; 12M_Load: p = 0,88). Ostatecznie po 18 i 24 miesiącach od czyn-nościowego obciążenia wszczepu związek między BMD a strukturą brzegu kości wyrostka zębodołowego wokół wszczepu zębowego pojawia się ponownie (18M_Load: p < 0,05; 24M_Load: p < 0,05).
Wnioski. Ocena gęstości mineralnej lędźwiowego odcinka kręgosłupa może być użytecznym wskaźnikiem do
osiągnięcia sukcesu implantologicznego. Na podstawie uzyskanych wyników badań stwierdzono, iż moment siły wprowadzenia wszczepu zębowego jako pojedynczy czynnik jest niewystarczającym narzędziem prognostycznym powodzenia leczenia implantologicznego (Dent. Med. Probl. 2014, 51, 4, 448–457).
Słowa kluczowe: wszczepy zębowe, entropia, moment siły wprowadzania wszczepu, gęstość mineralna kości
aration [8–11]. Many researchers revealed a mean-ingful dependence between cortical bone height and bone mineral density of lumbar spine [12, 13]. The aim of this study was to evaluate the influence of dental implant insertion torque and bone min-eral density of lumbar spine on the structure of the marginal bone in the alveolar crest after func-tional loading.
Material and Methods
The examination included 107 patients of dif-ferent gender aged between 17–67 (45.53 ± 12.1). Patients submitted informed consent for survey. Ethical Board permission: RNN/27/12/KE. 249 implants have been studied: MIs (sevenTM,
Bio-comTM) 157, Alpha-BioTM (sPI, sFB, ATI, DFI)
45, ABTM (i5) 24, WolfTM (ForMe) 8, OssTEMTM
(Gs3) 8, Dentsply (Ankylos C/XTM) 7.
Inclusion criteria: available L1–L4 BMD [g/cm2], torque force within 10–60 [Ncm],
visual-ization of the implant in full length.
Exclusion criteria: no response in follow-up examination, diagnose metabolic or bone disease during the investigation, drug affecting bone me-tabolism.
After implantation, the manual wrench was used to measure torque force (T). The range of torque force from 10–60 Ncm was noticed. First, four lumbar vertebrae (L1–L4) was the area of interest. BMD (g/cm2) was performed by a
du-al-energy X-ray absorptiometry (DXA) machine. Dental intraoral X-rays were taken directly post-implantation (00M) and control X-rays immedi-ately post loading implants in following months: 0, 3, 6, 9, 12, 18, 24 (00M_Load, 03M_Load, 06M_Load, 09M_Load, 12M_Load, 18M_Load, 24M_Load). Prosthetic restorations were cement-ed to abutments. We uscement-ed straight angle technique for X-rays images which were used during typical clinical follow-up. scans were made by FocusTM
X-ray device (Instrumentarium Imaging, Tuu-sula, Finland). We used DigoraTM system
record-ing plates (soredexTM, Orion Corporation,
Helsin-ki, Finland) – the analogue system of image ed-iting was excluded. selenium layer was an active part of recording plates. size of the X-ray point (pixel) was 70 × 70 mm [14]. Images were per-formed by standardized technique [15]. Exposure time – 0.1 s, intensity – 7 mA, constant voltage of X-ray tube was 70 kV [14]. Afterwards, the re-cording plates were scanned. These pictures were consigned to the database archive of DigoraTM
for Windows 1.51 [14, 15]. To set the film repeat-edly, the silk mass was used. Film fixing brack-et was sbrack-et up by mass. After that, when the mass
became hard, X-rays were taken. Then, the mass was removed from the holder, stow, patient data was noted and kept in the archive until the next visit. Although this method was used, minor in-accuracies occurred in the images. The next step needed to be revised. The first phase of the study, before the dental picture analysis, was the normal-ization of X-rays. Even small distortions had to be removed. Each dental image for the same patient were aligned to direct implantation X-ray (00M). In digital geometrical standardization, pairs of topographic pointers were placed. They were used at the same positions around dental implants (10 points) on the twin pictures in the same person. ToothVis 1.6 software was used to adjust the de-formations [16]. The accuracy of normalization was verified by Dental studio (by means of Flip-per and subtraction functions). FlipFlip-per func-tion cause alternate bounded manifestafunc-tion con-trol and aligned image. When points were moving (tremor of the implant) the revision was possible by Geometric Alignment function, and afterwards subtraction. If the dental pictures were correctly adjusted, the area of the implant faded away, and only the prosthetic crown was visible. When the X-ray picture of the same patient contained sev-eral implants, it was not possible to correct them all together. Each implant was corrected separate-ly, which significantly increased the precision of the normalization. By counterbalancing the defor-mation markers around implants on the X-ray pic-tures of the same patient in following control ap-pointment were the same.
Two regions of interest were marked in the bone image (ROI1: in implant neck region, ROI2: in periapical region) (Fig. 1). Every anatomical structure, i.e. alveolar ridge of maxillary sinus, incisive foramen, mental foramen, roots, crowns of the teeth, was omitted to enhance the appear-ance in ROI. For this aim we used MaZdaTM 4.5
software. (invented by the Institute of Electron-ics, Lodz University of Technology – szczypiński, Friedliner, Kociołek, strzelecki, Materka). 8-bit X-ray dental pictures were converted to 7-bit im-ages to diminish the initial noise. Imim-ages had previously been corrected ROI analogues to fol-low X-rays of the same person; monitoring ROI marked digital image was analyzed. Textural en-tropy parameter was analyzed as a factor that responds to the formation of mature trabecu-lar bone [6]. Then, the relation between age and entropy of microarchitecture of bone image was studied.
statistical analysis was performed in stat-graphics CenturionTM XIV. ANOVA and analysis
of regression was used. The level of significance was established as p < 0.05.
Results
The output shows the results of fitting a recip-rocal-y logarithmic-x model to describe the relation-ship between implant torque force (T) and L1–L4 BMD (BMD). The equation of the fitted model is:
T = 1,
0.021 + 0.029 × ln(BMD)
where T – implant insertion torque in Ncm, BMD – L1 to L4 lumbar vertebrae bone mineral density in g/cm2, ln – natural logarithm. since the p value
in the ANOVA table is less than 0.05 (i.e. p = 0.0031 and F = 8.97), there is a statistically significant re-lationship between implant insertion torque and L1 to L4 lumbar vertebrae bone mineral density at
the 95.0% confidence level (R2 = 4.35%, the
corre-lation coefficient is 21%).
Next, after analyzing the polynomial regres-sion results of fitting a 5th order model to
de-scribe the relationship between insertion torque and L1–L4 BMD (Fig. 2), the equation of the fit-ted model was calculafit-ted (p = 0.0062; F = 3.36; R2 = 8.01%):
T = –58258 + 238209 × BMD – 385942 × BMD2 +
+ 309983 × BMD3 – 123434 × BMD4 +
+ 19494 × BMD5
There is no relation between torque force and structure of alveolar bone surrounding neck of the dental implants on every period of investiga-tion (ANOVA 00M: F = 0.72, p = 0.67; 00M_load:
Fig. 1. series of analyzed radiographs with marked ROI1 (marginal crestal bone) and ROI2 (reference periapical
bone) 00M – immediately post-operational, 00M_Load – just before functional loading, 03M_Load – 3 months after functional loading, 06M_Load – 6 months after functional loading, 09M_Load – 9 months after functional loading, 12M_Load – 12 months after functional loading, 18M_Load – 18 months after functional loading,
24M_Load – 24 months after functional loading
Ryc. 1. seria analizowanych wewnątrzustnych cyfrowych zdjęć rentgenowskich z zaznaczonymi obszarami
zaintereso-wania: ROI1 (miejsce badawcze przy szyjce implantu) i ROI2 (miejsce kontrolne przy wierzchołku implantu) 00M – bezpośrednio po implantacji, 00M_Load – bezpośrednio po czynnościowym obciążeniu wszczepu,
03M_Load – 3 miesiące po czynnościowym obciążeniu wszczepu, 06M_Load – 6 miesięcy po czynnościowym obcią-żeniu wszczepu, 09M_Load – 9 miesięcy po czynnościowym obciąobcią-żeniu wszczepu, 12M_Load – 12 miesięcy po czyn-nościowym obciążeniu wszczepu, 18M_Load – 18 miesięcy po czynczyn-nościowym obciążeniu wszczepu, 24M_Load – 24 miesiące po czynnościowym obciążeniu wszczepu
F = 1.27, p = 0.26; 03M_Load: F = 1.19, p = 0.31; 06M_Load: F = 0.3, p = 0.96; 09M_Load: F = 1.41, p = 0.23; 12M_Load: F = 1.44, p = 0.2; 18M_Load: F = 0.74, p = 0.64; 24M_Load: F = 1.02, p = 0.41). Above relations are presented in Fig. 3.
Marginal crestal bone structure is related to bone mineral density of first 4 Lumbar vertebrae i.e. in patients with higher L1–L4 BMD, entropy measured in intraoral radiographs lower (analysis of regression 00M: correlation coefficient = 0.17, R2 = 2.86%, p < 0.05). Next, the process of
osseo-integration and bone remodeling after dental im-plant placement erase that relation (00M_load: correlation coefficient = 0.06, R2 = 0.37%, p = 0.42;
03M_Load: correlation coefficient = 0.01, R2 = 0.01%, p = 0.89; 06M_Load: correlation
coeffi-cient = –0.05, R2 = 0.25%, p = 0.66; 09M_Load:
cor-relation coefficient = –0.08, R2 = 0.66%, p = 0.56;
12M_Load: correlation coefficient = –0.02, R2 = 0.04%, p = 0.88). And finally, after 18 and
24 months of functional loading again nature of relation BMD to crestal bone around dental im-plant is expressed (18M_Load: correlation coeffi-cient = 0.25, R2 = 6.1%, p < 0.05; 24M_Load:
cor-relation coefficient = 0.35, R2 = 12.31%, p < 0.05)
(Fig. 4).
Discussion
In this study we attempted to find an easy to use implantation success prediction factor. We considered L1–L4 BMD, as the examination re-vealed the general quality of bone and torque force as a stability and later osseointegration predictor as well as local bone quality measure.
Many researchers tried to answer the question about the relation between stability and implant insertion torque. The measurement of torque force necessary to surgically screw the implant in artifi-cial alveolus is a parameter for examining primary stability. space between implant and bone should be without micromotions over a safely range [7]. Exceeding micromotions above this border could cause resorption and fibrosis and, thus, implant failure in the future [6, 7, 17]. The threshold of the micromotion is in the interval of 50–150 microm-eters [7, 18–20]. Movement limitation is a condi-tion to achieve primary stability and osseointe-gration [7, 21]. Lack of statistical relation has been reported, when insertion torque was compared with resonance frequency [7, 22, 23]. They also re-corded a very high peak insertion torque value of 178.5 Ncm (by an electric surgical unit) [23]. There were no explanations to the peak values (surgical unit should stop when the 70 Ncm was reached). Khayat et al. [8] coincided with our study and
re-Fig. 2. Relationship between torque force and L1–L4 BMD
Ryc. 2. Związek między momentem siły wprowadzenia wszczepu i gęstością mineralną lędźwiowego odcinka
Fig. 3. No relationship between torque force and textural entropy of bone image in dental implant neck region.
ANOVA: A – just after implant bone merge and cover the wound (p = 0.67), B – immediately after functional ing of the implant (p = 0.26), C – 3 months after functional loading (p = 0.31), D – 6 months after functional load-ing (p = 0.96), E – 9 months after functional loadload-ing (p = 0.23), F – 12 months after functional loadload-ing (p = 0.2), G – 18 months after functional loading (p = 0.64), H – 24 months after functional loading (p = 0.41)
Ryc. 3. Brak zależności między momentem siły wprowadzenia wszczepu i entropią tekstury kości wokół szyjki
im-plantu. ANOVA: A – bezpośrednio po wprowadzeniu wszczepu (p = 0,67), B – bezpośrednio po czynnościowym obciążeniu wszczepu (p = 0,26), C – 3 miesiące po czynnościowym obciążeniu wszczepu (p = 0,31), D – 6 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,96), E – 9 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,23), F – 12 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,2), G – 18 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,64), H – 24 miesiące po czynnościowym obciążeniu wszczepu (p = 0,41)
A C E G H F D B
Fig. 4. Relationship between L1–L4 BMD and textural entropy of bone image in dental implant neck region. simple
regression of textural entropy vs. L1–L4 BMD: A – just after implant bone merge and cover the wound (p < 0.05), B – immediately after functional loading of the implant (p = 0.42), C – 3 months after functional loading (p = 0.89), D – 6 months after functional loading (p = 0.66), E – 9 months after functional loading (p = 0.56), F – 12 months after functional loading (p = 0.88), G – 18 months after functional loading (p < 0.05), H – 24 months after functional load-ing (p < 0.05)
Ryc. 4. Związek między gęstością mineralną kości odcinka lędźwiowego L1–L4 i entropią tekstury kości wokół szyjki
implantu. Regresja liniowa pomiędzy entropią tekstury i L1–L4 BMD: A – bezpośrednio po wprowadzeniu wszczepu (p < 0,05), B – bezpośrednio po czynnościowym obciążeniu wszczepu (p = 0,42), C – 3 miesiące po czynnościowym obciążeniu wszczepu (p = 0,89), D – 6 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,66), E – 9 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,56), F – 12 miesięcy po czynnościowym obciążeniu wszczepu (p = 0,88), G – 18 miesięcy po czynnościowym obciążeniu wszczepu (p < 0,05), H – 24 miesiące po czynnościowym obciążeniu wszczepu (p < 0,05) A C E F G H B D
vealed no negative effects of the high insertion torque on marginal bone lose or osseointegration. They use multithreaded dental implants. Torque was measured by electronic measuring device. They suspected that implant design could com-press the bone when they were being screwed and change the distribution of stress along the implant surface. They claimed that increasing the number of other design features on the implant raises the risk for bone resorption when using high inser-tion torques [7]. Grandi et al. [18] have also dem-onstrated a lack of correlation between torque and peri-implant bone resorption. Two splinted and early loaded implants were screw in the jawbones of 32 patients. The torque necessary to place im-plants was noted and radiographic assessment was made after 2, 6, 12 months. The values between 30–100 Ncm were used (mean 65 Ncm). There were no radiographic signs of necrosis during eval-uation. Meltzer et al. [24] have studied tapered im-plants with high values of insertion torques (mean 90–100 with values up to 120 Ncm). Implants were immediately loaded and checked up to 24 months. Almost all (66 from 67) have been osseointe-grated. Radiographic study did not show resorp-tion of the cortical crestal bone [23]. Our studies are consistent with the results reported by Trisi et al. [25, 26]. The authors have examined histo-logically the healing of implants with high torque values (up to 150 Ncm mean 110 Ncm). The follow-up to the 45th day has revealed lack of bone
necro-sis. The higher implant insertion torque the higher will be the initial stability obtained [6]. In opposite to the results presented in this study, 3 papers not-ed a statistically significant correlation between torque force and the resonance frequency values of implant stability after placement [8, 23, 27]. Trisi et al. [2] reported that in soft density bone with an insertion force of 20 and 35 Ncm the micromotions were over the risk threshold. They did not find mi-cromotions in hard or medium bones with any in-sertion torque or in soft bone when force achieved 45–70 Ncm. They claim that immediate loading may be considered even in low-density bone inser-tion torque when 45 Ncm is reached. In the soft bone, the maximum level of torque was 70 Ncm. If the force is higher, the implant starts to rotate be-cause of the damage to the bone-implant surface. In hard and medium bones, if insertion torque in-creases, the micromotion constantly decreases. In the soft bone the contractions appear at insertion force from 25–45, and slow down from 45–70.
Implant torque is not a sufficient prediction factor for dental implant success. That is why the authors tried to define an adjuvant factor for this purpose. Polynomial regression revealed an inter-esting relation of insertion torque to lumbar
ver-tebral bone mineral density. There are two local maxima: 1.005 g/cm2 and 1.34 g/cm2. This can be
explained by habit of surgeons who assume that the density of jawbone is related to the vertebral bone linearly. Then, when the jawbone is less dense, they avoid extensive drilling or bone tapping. This results in relatively high insertion torque in less L1–L4 BMD patients [the first maximum]. The second dental implant insertion torque maximum can be understood intuitively. High bone density requires higher force to immerse the implant.
We did not notice this in our study but some authors claimed that high insertion torque might cause too much compression on the surround-ing bone, so that osteonecrosis could occur (bone necrosis by pressure) [28]. It is usually limited to bone cortical. In cancellous bone, excessive com-pression is absorbed by the fracture of bone tra-beculae [18]. In clinical practice it is not so easy to achieve insertion torque higher than 100 Ncm. Numerous studies reported a minimum insertion torque values ranged 32–50 Ncm [8, 17, 29, 30]. Ottoni et al. [31] in their investigation on the im-mediate loading single tooth implants claimed that this could only be done when insertion torque was higher than 32 Ncm [8]. Neugebauer et al. [32] obtained similar findings that implants screwed with insertion torque higher than 35 Ncm were related with success [8]. In many studies, highest peak insertion torque range from 50 to approx. 70 Ncm [17, 33, 34]. some investigators have used an electric surgical unit to measure torque force (Os-seoCare, NobelBiocare AB, Göteborg, sweden). They measure force only beyond 50 Ncm (techni-cal limit) [8, 35, 36]. Rabel et al. [23] compared the primary stability of two dental implants systems. They noted mean insertion torque values of 28.8 and 25.9 Ncm [8]. The threshold of torque force necessary to avoid necrosis has not been defini-tively established. It is suggested in some articles not to overstep the volume of 80–90 Ncm [18].
Entropy is a measure of disorder. It is claimed that texture evaluation parameter increases in ROI while bone healing. Over this time, the bone be-comes more and more complex. During this pro-cess when heterogeneity in optical density oc-curs, the entropy should increase. Maximal entro-py achieved in healthy and healed trabecular bone tissue. It has been found that the pattern of param-eter is not depended on gender or place. They ad-mit this parameter as a very useful assessment fea-ture of bone regeneration [6].
In our study we have tried to find an easy forecast factor to achieve implantation success. We have considered L1–L4 BMD, as examinations revealed the quality of bone and torque force as a stability and later osseointegration factor.
Marginal crestal bone structure is related to bone mineral density of first 4 lumbar vertebrae, i.e. in patients with higher L1–L4 BMD, entropy measured in intraoral radiographs was decreased (maybe thicker trabeculae creates more homoge-nous pattern on a radiograph). Next, the process of osseointegration and bone remodeling after dental implant placement make that phenomenon disap-pear. And finally, after 18 and 24 months of func-tional loading again, the nature of relation BMD to crestal bone around dental implant is expressed. Most likely that is the duration required for bone remodeling around the dental implant in func-tional loading.
The measurement of BMD could be a useful hint to evaluate dental implant indications. Mili-uniene et al. [13] have investigated the relationship between bone mineral density of lumbar spine (area L2–L4) and mandibular cortical bone high. 130 women participated in their study. They used panoramic X-ray images. They measured the cor-tical thickness at the mental foramen and at the angle of the jaw. The authors have found a
signifi-cant dependence between BMD and cortical bone height in this place. They have discovered the re-lationship between low radiomorphometric pa-rameters and osteoporosis. According to our re-sults, another study performed on Chinese adults by Li et al. [37] tried to find the correlation be-tween BMD of the: mandible and lumbar verte-brae. To measure the BMD, they used dual-ener-gy X-ray absorptiometry (DXA). The authors have demonstrated a correlation between BMD of man-dibular angles and lumbar vertebrae and have sug-gested that bone mineral density of mandibular angles could be a useful predicting factor for os-teoporosis.
As opposed to our results, there are some ex-aminations that have not found any relationship between bone mineral densities of mandible and skeleton [22, 38, 39].
Assessment of bone mineral density of lumbar vertebra could be a useful parameter to achieve dental implant success. In our opinion insertion torque force is not a sufficient prediction factor for dental implant success.
References
[1] Brånemark P-I., Breine U., Adell R., Hansson B.O.: Osseointegrated implants in the treatment of the edentulous jaw: Experience from a 10-year period. scand. J. Plast. Reconstr. surg. Hand. surg. 1977, 11 (suppl 16), 1–132. [2] Trisi P., Berardi D., Paolantonio M., spoto G., D’Addona A., Perfetti G.: Primary stability, insertion torque,
and bone density of conical implants with internal hexagon: is there a relationship? J. Craniofac. surg. 2013, 24, 841–844.
[3] Maciejewska I., Nowakowska J., Bereznowski Z.: Osteointegration of titanium dental implants: phases of bone healing. A review article. Protet. stomatol. 2006, 56, 214–219 [in Polish].
[4] Taylor D., Hazenberg J.G., Lee T.C.: The cellular transducer in damage-stimulated bone remodeling. A theo-retical investigation using fracture mechanics. J. Theor. Biol. 2003, 225, 65–75.
[5] Gładkowski J., Łomżyński Ł., Okoński P., Bączkowski B., Mierzwińska-Nastalska E.: Dental implants sta-bility assessment methods. Implantoprotet. 2008 9, 16–19 [in Polish].
[6] Kołaciński M., Kozakiewicz M., Materka A.: Textural entropy as a potential feature for quantitative assess-ment of jaw bone healing process. Arch. Med. sci. 2013, 24, 109–1115.
[7] Lioubavina-Hack N., Lang N.P., Karring T.: significance of primary stability for osseointegration of dental im-plants. Clin. Oral Imim-plants. Res. 2006, 17, 244–250.
[8] Khayat P.G., Arnal H.M., Tourbah B.I., sennerby L.: Clinical outcome of dental implants placed with high in-sertion torques (Up to 176 N/cm). Clin. Implant. Dent. Relat. Res. 2013, 15, 227–233.
[9] Beer A., Gahleitner A., Holm A., Tschabitscher M., Homolka P.: Correlation of insertion torques with bone mineral density from dental quantitative CT in the mandible. Clin. Oral Implants. Res. 2003, 14, 616–620. [10] Martinez H., Davarpanah M., Missika P., Celletti R., Lazzara R.: Optimal implant stabilization in low
den-sity bone. Clin. Oral Implants Res. 2001, 12, 423–432.
[11] Meredith N.: Assessment of implant stability as a prognostic determinant. Int. J. Prosthodont. 1998, 11, 491–501. [12] Devlin H., Horner K.: Mandibular radiomorphometric indices in the diagnosis of reduced skeletal bone mineral
density. Osteoporos. Int. 2002, 13, 373–378.
[13] Miliuniene E., Alekna V., Peciuliena V., Tamulaitiene M., Maneliene R.: Relationship between mandibular cortical bone height and bone mineral density of lumbar spine. stomatologija 2008, 10, 72–75.
[14] Martins M.G., Whaites E.J., Ambrosano G.M., Haiter Neto F.: What happens if you delay scaning Digora phosphor storage plates (PsPs) for up to 4 hours? Dentomaxillofac. Radiol. 2006, 35, 143–146.
[15] Kozakiewicz M., Wilamski M.: standarization technique of intraoral X-ray pictures. Czas stomatol. 1999, 52, 673–677 [in Polish].
[16] Kozakiewicz M., Bogusiak K., Hanclik M., Denkowski M., Arkuszewski P.: Noise in subtraction images made from pairs of intra oral radiographs: a comparison between four methods of geometric alignment. Dento-maxillofac. Radiol. 2008, 37, 40–47.
[17] Calandriello R., Tomatis M., Rangert B.: Immediate functional loading of Brånemark system implants with enhanced initial stability: a prospective 1- to 2-year clinical and radiographic study. Clin. Implant Dent. Relat. Res. 2003, 13, 10–20.
[18] Grandi T., Garuti G., Guazzi P., sapio U., Forabosco A.: A longitudinal, multicenter study on the relationship between insertion torque and peri-implant bone resorption. J. Clin. Pract. Oral Implantol. 2010, 1, 33–40. [19] szmukler-Moncler s., salama s., Reingewirtz Y., Dubruille J.H.: Timing of loading and effect of
micromo-tion on bone implant interface: a review of experimental literature. J. Biomed. Mat. Res. 1998, 43, 192–203. [20] szmukler-Moncler s., Piatelli A., Favero G.A., Dubruille J.H.: Considerations preliminary to the
applica-tion of early and immediate loading protocols in dental implantology. Clin. Oral Implants Res. 2000, 11, 12–25. [21] Mohajery M., Brooks s.L.: Oral radiographs in the detection of early sighs of osteoporosis. Oral surg. Oral Med.
Oral Pathol. 1992, 73, 112–117.
[22] Nkenke E., Hahn M., Weinzierl K., Radespiel-Tröger M., Neukam F.W., Engelke K.: Dental implant stabil-ity and histomorphometry: a correlation study in human cadavers. Clin. Oral Implants Res. 2003, 14, 601–609. [23] Rabel A., Köhler s.G., schmidt-Westhausen A.M.: Clinical study on the primary stability of two dental
im-plant systems with resonance frequency analysis. Clin. Oral Investig. 2007, 11, 257–265.
[24] Meltzer A., Baumgarten H., Testori T., Trisi P.: Pressure necrosis and osseointegration. Clin. Res. 2009, Biomet 3i.
[25] Trisi P.: Immediate or late reconstructions in partially edentulous patients: Effect regarding hard tissue aspects. 15TH Annual scientific Meeting of the European Association of Osseointegration, Kongresshaus Zurich, Zurich, switzerland, 2006.
[26] Trisi P., Todisco M., Consolo U., Travaglini D.: High versus low implant insertion torque: a histologic, histo-morphometric, and biomechanical study in the sheep mandible. Int. J. Oral Maxillofac. Implants 2011, 26, 837–849. [27] Friberg B., sennerby L., Meredith N., Lekholm U.: A comparison between cutting torque and resonance fre-quency measurements of maxillary implants. A 20-months clinical study. Int. J. Oral Maxillofac. surg. 1999, 28, 97–103.
[28] Winwood K., Zioupos P., Currey J.D., Cotton J.R., Taylor M.: The importance of elastic and plastic compo-nents of strain in tensile and compressive fatigue of human cortical bone in relation to orthopedic biomechanics. J. Musculoskelet Neuronal Interact. 2006, 6, 134–141.
[29] Nikellis I., Levi A., Nicolopoulos C.: Immediate loading of 190 endosseous dental implants: a prospective obser-vational study of 40 patients treatments with up to 2-years data. Int. J. Oral Maxillofac. Implants 2004, 19, 116–123. [30] Hui E., Chow J., Li D., Liu J.,Wat P., Law H.: Immediate provisional single-tooth implant replacement with
Brånemark system: preliminary report. Clin. Implant Dent. Relat. Res. 2001, 3, 79–86.
[31] Ottoni J.M., Oliveira Z.F., Mansini R., Cabral A.M.: Correlation between placement torque and survival of single-tooth implants. Int. J. Oral Maxillofac. Implants 2005, 20, 769–776.
[32] Neugebauer J., Traini T., Thams U., Piatelli A., Zöller J.E.: Peri-implant bone organization under immedi-ate loading stimmedi-ate. Circularly polarized light analyses: a minipig study. J. Periodontol. 2006, 77, 152–160.
[33] O’sullivan D., sennerby L., Meredith N.: Measurements comparing the initial stability of five designs of den-tal implants: a human cadaver study. Clin. Implant Dent. Relat. Res. 2000, 2, 85–92.
[34] Friberg B., sennerby L., Gröndahl K., Bergström C., Bäck T., Lekholm U.: On cutting torque measurements during implant placement: a 3 years clinical prospective study. Clin. Implant Dent. Relat. Res. 1999, 1, 75–83. [35] Alsaadi G., Quirynen M., Michiels K., Jacobs R., Van steenberghe D.: A biomechanical assessment of the
relation between the oral implant stability at insertion and subjective bone quality assessment. J. Clin. Periodontol. 2007, 34, 359–366.
[36] Turkyilmaz I., Tumer C., Ozbek E.N., Tözüm T.F.: Relations between the bone density values from computer-ized tomography, and implant stability parameters: a clinical study of 230 regular platform implants. J. Clin. Perio-dontol. 2007, 34, 716–722.
[37] Li N., Jing H., Li J., Zhou F., Bu L., Yang X.: study of mandible bone mineral density of Chinese adults by dual-energy X-ray absorptiometry. Int. J. Oral Maxillofac. surg. 2011, 40, 1275–1279.
[38] Bollen A.M., Taguchi A., Hujoel P.P., Hollender L.G.: Case-control study on self-reported fractures and mandibular cortical bone. Oral surg. Oral Med. Oral Radiol. Endod. 2000, 90, 518–524.
[39] Balcikonyte E., Balciuniene I., Alekna V.: Panoramic radiographs in assessment of the bone mineral density. stomatologija. Baltic Dent. Maxillofac. J. 2004, 6, 17–19.
Address for correspondence:
Piotr HadrowiczDepartment of Maxillofacial surgery Medical University of Lodz
Żeromskiego 113 90-459 Łódź Poland
Tel.: +48 42 639 37 81
E-mail: piotrhadrowicz@gmail.com Conflict of Interest: None declared
Received: 6.05.2014 Revised: 23.07.2014 Accepted: 12.08.2014
Praca wpłynęła do Redakcji: 6.05.2014 r. Po recenzji: 23.07.2014 r.
