Flashcards in perio1 Deck (149):
Which statement regarding an autogenous free gingival graft is true? Select all that apply.• it can be placed to prevent further recession• it can be used to effectively widen the attached gingiva• it retains its own blood supply and is not dependent on the bed of recipient blood vessels• the greatest amount of shrinkage occurs within the first 6 weeks• it is also useful for covering nonpathologic dehiscences and fenestrations
• it can be placed to prevent further recession• it can be used to effectively widen the attached gingiva• the greatest amount of shrinkage occurs within the first 6 weeks• it is also useful for covering nonpathologic dehiscences and fenestrations
the donor site of an autogenous free gingival graft from which the graft is taken is ?
an edentulous region or the palatal area
The graft epithelium undergoes ? after it is placed. Then it sloughs, the 'epithelium " is reconstructed in about ? by the adjacent epithelium and proliferation of ?. In 2 weeks the tissue appears to have reformed, but maturation is not completed until ? weeks
• degeneration • a week • surviving donor basal cells• 10-16
The free gingival graft receives its nutrients from the ?
viable connective tissue bed
The graft may be used to correct ? but not ?
localized narrow recessions or cleftsdeep, wide recessions
Miller classification system for marginal tissue recession:
• Class I: no extension to the mucogingival junction• Class II: extension to or beyond the mucogingival junction + no loss of bone or soft tissue in the interdental areas• Class III: extension to or beyond the mucogingival junction + loss of bone or soft tissue in the interdental areas OR malpositioning of the tooth• Class IV: There is severe bone and soft tissue loss interdentally or severe tooth malposition
the prognosis for classes I and II is ?; whereas for class III, ?. Class IV has ?
• good to excellent• only partial coverage can be expected• a very poor prognosis
Hemisection is most likely to be performed on:• mandibular first and second premolars• maxillary first and second molars• maxillary canines• mandibular molars with buccal and lingual class II or III furaction involvements
mandibular molars with buccal and lingual class II or III furaction involvements
Hemisection has been called ? because it changes the molar into two separate roots.
bicuspidization or segaration
? refers to the separation of an individual root from the crown structure of the tooth.
Most root amputations involve ?
the maxillary first and second molars
Root amputations or hemisections almost always result in irreversible pulpal damage that demands endodontic therapy. Ideally, when the endo is done ?
The? pontics have convex undersurfaces, which makes them easiest to clean. The ? designs have concave surfaces, which are more difficult to access with dental floss
sanitary and ovateridge-lap and modified ridge-lap
the ideal pontic form?
ovate pontic (The alveolar bone must be a minimum of 2 mm from the most apical portion of the pontic)
The main goal of osseous recontouring (surgery) is:• to cure periodontal disease• to eliminate the existing microflora• to eliminate periodontal pockets• to change the existing microflora
eliminate periodontal pockets — to reshape the marginal bone to resemble that of the alveolar process undamaged by periodontal disease
The most critical factor in determining whether a tooth should be extracted or have surgery performed on it is ?
the amount of attachment loss
Material to be grafted can be obtained from the same individual (?), from a different individual of the same species (?), or from a different species (?).
• osteogenic potential of bone grafting materials• osteoinductive potential of bone grafting materials• osteoconductive potential of bone grafting materials
• ability to induce the formation of new bone by cells contained in the graft• (ability of molecules contained in the graft to convertneighboring cells into osteoblasts• ability of the graft material to serve as a scaffold that favors outside cells to penetrate the graft and form new bone
All of the following statements regarding periodontal flaps are true EXCEPT one. Which one is the EXCEPTION!• full-thickness periodontal flaps involve reflecting all of the soft tissue, including the periosteum, to expose the underlying bone• the partial-thickness periodontal flap includes only the epithelium and a layer of the underlying connective tissue• both full-thickness and partial-thickness periodontal flaps can be displaced • flaps from the palate are considered easier to be displaced than those from any other region• flaps should be uniformly thin and pliable
flaps from the palate are considered easier to be displaced than those from any other region (palatal flaps cannot be displaced)
a full thickness flap will be used where the attached gingiva is ?, and a partial-thickness flap may be used when the attached gingiva is ?
thin (2 mm or less in width)thick (2 mm or more)
There are various distal flap approaches used for retromolar reduction. The simplest is the:• gingivectomy • apically positioned flap• distal wedge• laterally positioned flap
distal wedge (sometimes called proximal wedge procedures)
indications to gingivectomy include ?
• elimination of gingival enlargements• Elimination of suprabony pockets, regardless of their depth, if the pocket wall is fibrous and firm• Elimination of suprabony periodontal abscesses
The following factors should be considered when electing to perform a gingivectomy rather than a periodontal flap:• Pocket depth (?)• Need for access to bone (?)• Amount of existing attached gingiva (?)
• if base of pocket is located at the mucogingival junction or apical to the alveolar crest, do not perform gingivectomy• if osseous recontouring is needed, do not do gingivectomy• if inadequate, do not do gingivectomy
A gingivoplasty is directed toward reshaping the gingiva and papilla of a tooth for correction of ?. The overall objective is not to eliminate periodontal pockets but, rather, to provide a ?
• deformities and to provide the gingiva with normal and functional form• more,physiological tissue contour
which procedure is commonly used to correct the tissue contours that result from ANUG
The primary objective and advantage of surgical flap procedures in the treatment of periodontal disease is:• reduce or eliminate periodontal pockets• to provide access to root surfaces for debridement• regrowth of alveolar bone• maintenance of biological width• establishment of adequate soft tissue contours
to provide access to root surfaces for debridement (choices are goals but not a primary objective)
The modified Widman flap:• in addition to improving accessibility for instrumentation, removes the pocket wall, thereby reducing or eliminating the pocket• facilitates instrumentation but does not attempt to reduce pocket depth• improves accessibility and eliminates the pocket, but does the latter by apically positioning the soft tissue wall of the pocket• none of the above
facilitates instrumentation but does not attempt to reduce pocket depth
The reduction or elimination of pocket depth is the main purpose of two flap techniques?
• the undisplaced flap (most frequently performed type of periodontal surgery) [=internal bevel gingivectomy]• the apically displaced flap
the two techniques that surgically remove the pocket wall?
the.undisplaced flap and the gingivectomy
A soft tissue graft that is rotated or otherwise repositioned to correct an adjacent defect is called a:• free gingival graft• pedicle graft• connective tissue graft• frenectomy
pedicle graft (The base of the graft remains attached tothe donor site to maintain the blood supply) (designed for repair of isolated not generalized recession)
What is guided tissue regeneration?• a soft tissue graft used to correct mucogingival junction involvement• placement of nonresorbable barriers or resorbable membranes and barriers over a bony defect• a free gingival graft used to increase the amount of attached gingiva• placement of an autograft to treat a bony defect
placement of nonresorbable barriers or resorbable membranes and barriers over a bony defect
The primary reason for the failure of a free gingival autograft is:• infection• edema• disruption of the vascular supply before engraftment• the formation of scar tissue
disruption of the vascular supply before engraftment (The second most common reason is infection)
A variation of the laterally positioned flap is called:• a coronally positioned flap• a modified Widman flap• a double papilla flap• a free gingival flap
a double papilla flap
Techniques used to increase the width of attached gingiva include ? These techniques are used for widening the attached gingiva apical to the area of recession
the free gingival autograft, the connective tissue autograft, the apically positioned flap
Techniques used for gingival augmentation coronal to the recession (root coverage) include ?
• the free gingival and connective tissue autograft, • pedicle autografts (laterally and coronally positioned flaps), • the subepithelial connective tissue graft (Langer), • guided tissue regeneration
The ideal thickness for the free gingival graft is ?
1 to 1.5 mm
There is no necrotic slough of positioned flaps (?) because these flaps take their vascular supply with them
laterally, coronally, and apically positioned flap
Deep periodontal pockets are often treated by flap surgery. These cases will often result in reduced pocket depth by ?, even if there is no change in the position of the gingival margins
formation of a long junctional epithelium (soft tissue reattachment)
The best indicator of success of a periodontal flap procedure is ?
postoperative maintenance and plaque control by the patient
how long after flap surgery, a fully epithelialized gingival crevice with a well-defined epithelial attachment is present? Functional arrangement of supracrestal fibers is initiated
All corners of a periodontal flap should be:• sharp• rounded• it doesn't matter whether the corners of a periodontal flap are sharp or rounded
Which of the following has a relatively high degree of predictability and is a "workhorse" of periodontal therapy?• coronally displaced (positioned) flap• laterally displaced (positioned) flap• double papilla flap• apically displaced (positioned) flap
apically displaced (positioned) flap
indications of apically displaced (positioned) flap?
• Moderate or deep pockets• Furcation-involved teeth• Crown lengthening
contraindications of apically displaced (positioned) flap?
• a patient is at risk for root caries• tooth exposure would be unesthetic
For all mucogingival procedures, what is the most significant concern?
the root surface of the pocket can be treated to improveits chances of accepting the new attachement of gingival tissues. Several substances have been proposed for this purpose, including ?
citric-acid, fibranectin, and tetracycline. Other agents used include growth factors and one enamel matrix protein derivative obtained from developing porcine teeth (trade name is Emdogain).
Which of the following mucogingival surgical techniques is indicated in areas of narrow gingival recession adjacent to a wide band of attached gingiva that can be used as a donor site?• free gingival autograft• double papilla flap• modified Widman flap• laterally displaced (positioned) flap
laterally displaced (positioned) flap
A free mucosal autograft (subepithelial connective tissue graft) differs from a free gingival graft in that the transplant in a free mucosal graft is:• connective tissue with an epithelial covering• connective tissue without an epithelial covering• epithelial tissue with its own blood supply• epithelial tissue without its own blood supply
connective tissue without an epithelial covering (often used on canines where there is little keratinized gingiva to create a band of gingiva-like tissue)
the epithelium of free gingival grafts degenerates (necrotic slough), and re-epithelialization occurs by ?
• proliferation of epithelial cells from adjacent tissue • surviving basal cells of the graft tissue
Full-thickness flaps,,which denude the bone, result in ?
a superficial bone necrosis (a loss of bone of about 1 mm; bone loss is greater if the bone is thin.)
Which of the following terms refers to reshaping the bone without removing tooth-supporting bone?• ostectomy• osteoplasty• positive architecture• negative architecture
The most common osseous defects are:• one-wall intrabony defects• two-wall intrabony defects (osseous craters)• three-wall intrabony defects• through-and-through furcation defects
two-wall intrabony defects (osseous craters)
The architecture is said to be "positive" if the radicular bone is ?
apical to the interdental bone.
Flat architecture is ?
the reduction of the interdental bone to the same height as the radicular bone
Osseous form is considered to be "ideal" when ?
the bone is consistently more coronal on the interproximal surfaces than on the facial and lingual surfaces
Angular defects are classified on the basis of ?
the number of osseous walls (one, two, or three walls)
? is the only sure way to determine the presence and configuration of vertical osseous defects
? is the most common side effect of osseous grafting
A dehiscence is ?
a loss of the buccal or lingual bone overlaying the root portion of a tooth, leaving the area covered by soft tissue only
The three-wall vertical defect was originally called ?. This term was later expanded to designate all vertical defects
an intrabony defect
The one-wall vertical defect is also called a ?
Two-wall intrabony defects (osseous craters) are best corrected by ?
recontouring of the facial and lingual walls to restore normal interdental architecture
Smoking has been identified as a significant variable to predict the response to periodontal treatment.Smoking has a negative effect on periodontal therapy.• both statements are true• both statements are false• the first statement is true, the second is false• the first statement is false, the second is true
both statements are true
Prevotella intermedia was formerly known as:• bacteroides melaninogenicus• wolinella intermedius• bacteroides gingivalis• bacteroides intermedius
There is some evidence that some treatments for osteoporosis, such as ?, may reduce bone loss, including the bony structures that support the teeth
Smokless tobacco use has been associated with ?
oral leukoplakia and carcinoma (no generalized effects on periodontal disease progression)
Mediators produced as a part of the host response that contribute to tissue destruction include all of the following EXCEPT one Which one is the EXCEPTION!• free radicals• proteinases• prostaglandins• cytokines
Which of the following is the LEAST important diagnostic aid in recognizing the early stage of gingivitis?• bleeding on probing• gingival color• pocket depths• stippling of the gingival tissue
stippling of the gingival tissue
?are very important in regulating the immune response through the release of cytokines
The primary cells responsible for PGE2 production in the periodontium are ?
macrophages and fibroblasts
Induction of MMPs (=Matrix metalloproteinases which are primary proteinases) and osteoclastic bone resorption is induced by ?.
the most common color change noted with periodontal disease is ?
cyanosis (bluish-purple hue)
gingival texture (the so-called orange peel appearance) ?
stippling of the attached gingiva
scalloped in form
gingival Tone (or Consistency)?
resilient and fibrotic in nature from the free gingival groove apical to the mucogingival junction
The impact of nutrition on periodontal disease ?
there are no nutritional deficiencies that by themselves can cause gingivitis or periodontitis (Without bacterial plaque, there would be no gingivitis)
• Vitamin A deficiency• Vitamin D deficiency• Vitamin B-complex deficiency• Vitamin C deficiency
• can impact the barrier function of epithelial cells• no relationship• contribute to gingivitis• Bleeding, swollen gingiva, and loosened teeth are common features of scurvy
In a clinically healthy periodontium, the microbial flora is largely composed of:• gram-negative obligate microorganisms• gram-negative facultative microorganisms• gram-positive obligate microorganisms• gram-positive facultative microorganisms
gram-positive facultative microorganisms
Endotoxins are the lipopolysaccharide component of the cell wall of:• gram-positive bacteria• gram-negative bacteria• both gram-positive and gram-negative bacteria• neither gram-positive and gram-negative bacteria
? has a direct effect on the severity of gingivitis
• Collagenase catalyzes the degradation (hydrolysis) of ?• Hyaluronidase and chondroitin sulfatase may lead to the destruction of ?
• collagen• the amorphous ground substance
Antibodies or immunoglobulins are produced by plasma cells in response to oral bacteria or their by-products. The most numerous are ?, which act to neutralize ?
IgGbacterial toxins by enhancing phagocytosis
The most likely source of bacteria found in diseased periodontal tissue is ?
The predominant periodontal disease is ?
Two forms of necrotizing ulcerative periodontal diseases are ?
• necrotizing ulcerative gingivitis (NUG) • necrotizing ulcerative periodontitis (NUP)
The essential components of NUG are:
• Interdental gingival necrosis: often described as "punched-out" papillae• Pain• Bleeding
Which of the following clinical signs and symptoms is characteristic of necrotizing ulcerative gingivitis (NUG)!• minimal bleeding• punched-out" papillae• painless• periodontal pocket formation
Predominant organisms associated with NUG include ?
• P. Intermedia Fusobacterium species • spirochetal microorganisms
NUP is distinguished from NUG by ?, but the clinical presentation and etiologic factors are similar to that of NUG
the loss of clinical attachment and bone in affected sites
The treatment of NUG or NUP includes ?
debridement, hydrogen peroxide (or chlorhexidine) rinses, and antibiotic therapy (Pen^V) if there is systemic involvement (manifested by fever, malaise, and lymphadenopathy)
Patients with HIV-associated NUG require ?
gentle debridement and antimicrobial rinses
Treatment for patients with acute herpetic gingivostomatitis?
• If diagnosed within 3 days of onset, acyclovir suspension should be prescribed, 15 mg/kg five times daily for 7 days• All patients, including those presenting more than 3 days after disease onset, may receive palliative care, including plaque removal, systemic NSAIDs, and topical anesthetics
In a healthy sulcus, which of the bacteria below are most abundant?• actinobacillus actinomycetemcomitans and tannerella forsythus• streptococcus and actinomyces species• treponema and capnocytophaga species• prevotella intermedia and porphyromonas gingivalis
streptococcus (Gram-positive cocci) and actinomyces (filamentous) species
which Streptococci is abundant?
when S. mutans and sanguis appear ?
when teeth are present not earlier
By the age of ?, the oral flora resembles that of an adult
Early microbiologic studies of localized aggressive periodontitis (LAP) provided clear evidence of a strong association between disease and a unique bacterial microbiota dominated by:• tannerella forsythia• prevotella intermedia• porphyromonas gingivalis• actinobacillus actinomycetemcomitans (aa)
ctinobacillus actinomycetemcomitans (aa) — also calledaggregatibacter actinomycetemcomitans
Diseases that clinically present as desquamative gingivitis include the following?Select all that apply.• lichen planus• pemphigoid• pemphigus vulgaris• leukemia• chronic ulcerative stomatitis• lupus erythematosus
• lichen planus• pemphigoid• pemphigus vulgaris• chronic ulcerative stomatitis• lupus erythematosus
The role of plaque in desquamative gingivitis is ?
desquamative gingivitis can be mistaken for ?, and this can lead to delayed diagnosis and inappropriate treatment of serious dermatological diseases such as pemphigoid or pemphigus
? is the foundation for diagnosis of desquamative gingivitis lesions
in desquamative gingivitis lesions, inflammatory cells, mainly ?, may be found on the basal layer
A cuplike resorptive area at the crest of the alveolar bone is a radiographic finding of:• gingivitis• occlusal trauma• early periodontitis• acute necrotizing ulcerative gingivitis
Which of the following statements regarding periodontitis is incorrect?• periodontitis does not always begin with gingivitis• gingivitis and periodontitis cannot be induced without bacteria• there are no radiographic features of gingivitis• the presence of pockets cannot be determined from radiographs• chronic gingivitis does not always lead to periodontitis
periodontitis does not always begin with gingivitis (Periodontitis always begins as a gingivitis)
The clinical feature that distinguishes periodontitis from gingivitis is the presence of ?
clinically detectable attachment loss
In periodontitis, radiographic changes are noted, which may include the following?
• loss of lamina dura• horizontal or vertical bone resorption• thickening (widening) of the periodontal ligament space
The presence of pockets can/cannot ? be determined from the evaluation of radiographs
Ingestion of heavy metals (i.e., bismuth, lead, and mercury) may/may not? result in changes in the periodontium
Which of the following is most significant in regard to the prognosis of a periodontally involved tooth?• pocket depth• attachment loss• anatomical crown length• bleeding on probing
attachment loss [(most critical) and mobility]
Gingivitis is most often caused by:• a hormonal imbalance• inadequate oral hygiene• occlusal trauma• a vitamin deficiency• aging
inadequate oral hygiene — this leads to the formation of bacterial plaque and its products, which are the primary etiologic factors in gingivitis
When the gingival margin coincides with the CEJ, the loss of attachment equals?
the pocket depth
When the gingival margin is located apical to the CEJ, the loss of attachment is ? than the pocket depth, and therefore, the distance between the CEJ and the gingival margin should be added to ?
• greater • the pocket depth
Comparing the microbiota in health, gingivitis, and periodontitis, the following microbial shifts can be seen?
• From gram-positive to gram negative• From facultative anaerobes to obligate aerobes• From cocci to rods • From fermenting to proteolytic species• From nonmotile to motile organism
? cause bad breath (Halitosis) by their proteolysis
The gram-negative anaerobic bacteria associated with gingivitis and periodontitis
The major factor in determining the different bacteria is ?
Which of the following needs to be evident in to make a diagnosis of periodontitis?• bleeding• pocket depths of 5 mm or more• radiographic evidence of bone loss• a change in tissue color and tone
radiographic evidence of bone loss
The degree of gingival enlargement • grade 0• grade I• grade II• grade III
• grade 0: no signs of gingival enlargement• grade I: enlargement confined to interdental papillae• grade II: enlargement involves papilla and marginal gingiva• grade III: enlargement covers three-quarters or more of the crown
which type of x-rays tend to be most accurate in assessing alveolar bone resorption.
Bitewing (If extensive bone loss has occurred, vertical bitewings should be taken)
? of the bone mass at the alveolar crest must be lost for a change in bone height to be recognized on radiographs.
more than 30%
The loss of attachment is determined by ?
measuring the disttance between the CEJ and the base of the attachment
Bleeding in the absence of local irritants may indicate a ?
Enlargement confined to the interdental papilla would be scored as:• grade 0• grade 1• grade II• grade III
The most important plaque retentive factor is:• subgingival and/or overhanging margins of restorations• carious lesions that extend subgingivally• calculus• furcations exposed by loss of attachment and bone• crowded and malaligned teeth• root grooves and concavities
calculus (The nonmineralized plaque on the calculus surface is the principal irritant, but calculus may be a significant contributing factor)
During pregnancy there is an increase in levels of both progesterone and estrogen.The so-called pregnancy tumor is not a neoplasm.• both statements are true• both statements are false• the first statement is true, the second is false• the first statement is false, the second is true
both statements are true
the average biologic width is approximately ?
2 mm (approximately 0.97 mm for the junctional epithelium and 1.07 mm for the connective tissue attachment).
Conditions in which the influences of periodontal infection are documented include the following. Select all that apply.• coronary heart disease• atherosclerosis• stroke• cirrhosis of the liver• diabetes mellitus• low-birth-weight delivery
• coronary heart disease• atherosclerosis• stroke• diabetes mellitus• low-birth-weight delivery
PMNs are the predominant immune cells in which stage of gingivitis?
Neutrophils, or polymorphonuclear leukocytes (PMNs), predominate in the early stages of gingival inflammation, and these cells phagocytose and kill plaque bacteria
The four stages of the periodontal lesion are?
initial, early, established, and advanced
The frequency of maintenance visits for a patient who has had previous periodontal treatment should depend on which two factors?• on whether or not the patient feels that frequent visits will help maintain his/her periodontium• on the appearance and clinical condition of the gingival tissues• on the amount of attachment loss prior to the periodontal treatment• on the patient's ability to perform in-home-care
• on the appearance and clinical condition of the gingival tissues — this will determine if the patient is maintaining adequate plaque control• on the patient's ability to perform in-home-care — this will determine the effectiveness of the patient's oral hygiene
? is a critical period, since the patient has already demonstrated susceptibility to periodontal disease, the cause of which tends to be persistent and recurrent
The first year after treatment
Bleeding during circumferential probing indicates that ? is ulcerated due to active periodontal disease
the crevicular epithelium
After periodontal treatment, the first recall visit should be scheduled at ?. With excellent plaque control and maintenance of periodontal health, the interval may be lengthened to ?
• 3 months• 4 to 6 months
the menstrual cycle ? by notable gingival changes, however, increased gingival bleeding is often seen during this time
is not accompanied
Oral disturbances are not a common feature of menopause. Some females may develop ?
If one of the steps in the fabrication of your implant restoration is attaching an analogue to the impression post and then seating them both into the set impression material, you have made a/an:• open-tray impression• closed-tray impression• either of the above• neither of the above
An "implant level impression" means that:• the impression coping (or impression post) was attached to the implant• the impression coping was attached to the abutment• the impression captured or recorded the actual abutment attached to the implant• none of the above
the impression coping (or impression post) was attached to the implant
If the impression coping was attached to the abutment (which was attached to the implant), the impression is termed an ?
abutment level impression
Which of the following is NOT an advantage of retaining an implant-supported crown to an abutment with a screw (rather than with cement)!• the crown is retrievable• the residual cement excess in the sulcus is avoided• the occlusal surface of the crown is left intact• a shorter abutment may be used
the occlusal surface of the crown is left intact
In implant dentistry, an ?impression is used because the abutment retention screw must be unscrewed after set
In implantology, "countersinking" refers to the process of:• flaring or enlarging the coronal end of the osteotomy• reversing the engine to remove the implant• placing the implant in a counterclockwise rotation• torquing the abutment to place
flaring or enlarging the coronal end of the osteotomy
This process of creating the groove on the inside of the osteotomy wall is referred to as ?
tapping the osteotomy.
The purpose of the second-stage surgery in the creation of an implant restoration is to:• check on healing progress• remove the implant for cleaning• uncover the implant and place an abutment• determine which components will fit• all of the above
uncover the implant and place an abutment
The "macro design" of implants describes:• screw or cylinder shape• surface texture• alloy composition• surface coatings• none of the above
screw or cylinder shape
The microstructure of the implant is descriptive of ?
the surface quality or surface alteration (surface roughness)
? are examples of the roughening techniques
Sandblasting, acid etching, and titanium plasma spray processes
The soft tissue interface between the oral tissue and titanium can be? Select all that apply.• established by keratinized mucosa• established by nonkeratinized mucosa• dependent on hemidesmosomes• comparable with the interface on teeth
• established by keratinized mucosa• established by nonkeratinized mucosa• dependent on hemidesmosomes• comparable with the interface on teeth
When considering probing depths around implants and the associated attachment level, what landmark is used to determine the "clinical" attachment level?• CEJ• apical end of the implant• ball tip of the probe• implant shoulder or other permanent physical structure• radiograph
implant shoulder or other permanent physical structure (CEJ is used for the attachment level on teeth)
The advantage of using a screw shaped implant instead of a straight cylinder implant without threads is:• easier osteotomy preparation• increased initial stability• less force required to insert the implant• no antirotational components are necessary
increased initial stability