Histologic and histomorphometric findings from retrieved, immediately occlusally loaded implants in humans

BACKGROUND: The immediate loading treatment concept can be successfully used in implant dentistry. Bone cells migrate onto the implant surface and establish a stable anchorage on the titanium surface. When implants are loaded immediately after surgery, there is a high long-term success rate of the implant-supported reconstruction. Based on histologic observations from different animal studies, the interface of immediately loaded implants can have a direct bone-to-implant connection without any fibrous tissue formation. Mature bone formation is dependent on the loading period. The aim of this study was to demonstrate a histologic analysis of retrieved, clinically stable immediately loaded implants with different implant designs and surfaces. An objective demonstration of the bone-implant interface was presented for the implant systems used. METHODS: A total of 29 implants with different implant designs and surfaces were retrieved from patients who were treated with implants using an immediate loading protocol and fixed immediate restorations placed the same day after surgery. The loading period was between 2 and 10 months. The bone-implant interface was examined histologically and histomorphometrically. RESULTS: A high bone-to-implant percentage of 66.8% (+/-8.9%) was found in the examined retrieved implants. Some marginal bone resorption was observed in the crestal part of the implants. CONCLUSION: According to the present histologic and histomorphometric evaluation of retrieved, clinically stable implants, immediate occlusal loading can present a high level of bone-to-implant contact in humans.     

Marginal leakage in occlusally loaded, etched, class-II composite resin restorations

Microleakage was studied in class-II cavities restored with a calcium hydroxide liner and an adhesive system combined with two different posterior composite resins. The restorations were exposed to repeated loading when immersed in dye solution. The teeth were cut, and microleakage along the cavity walls and into dentin was evaluated by light microscopy. Dye penetration at the interface between the cavity and the restoration was recorded in 61% of the loaded and in 30% of the unloaded teeth. The difference between loaded and unloaded was greater for the teeth lined with Life than with Gluma dentin bonding.     

The clinical significance and management of apical accessory canals in maxillary central incisors

BACKGROUND: The maxillary central incisor is considered to be the least difficult subject for a clinical endodontic experience. However, the internal anatomy of maxillary central incisors can present a number of variations, including multiple accessory canals. CASE DESCRIPTION: This article highlights the clinical significance and management of accessory canals located in the apical one-third of maxillary central incisors. The authors present two case reports in which failure to detect the accessory canals led to root canal failure and subsequent surgical intervention. Another two case reports present the serendipitous discovery and nonsurgical management of accessory canals during the initial treatment of maxillary incisors. CONCLUSIONS AND CLINICAL IMPLICATIONS: It is important for the clinician to be able to detect the signs suggesting the presence of accessory canals in maxillary central incisors. Failure to do so may lead to a less-than-optimal endodontic treatment outcome.     

Endodontic therapy of traumatized incisors with crown and transverse intra-alveolar root fractures

A case involving traumatic injury to the maxillary anterior teeth with crown and transverse intra-alveolar root fractures is reported. The patient did not seek immediate treatment after trauma. Treatment included pulpectomy, fixation of a fractured root, root canal obturation, endodontic therapy of the coronal segment, and postoperative observation. Follow-up showed good results. Thus effective nonsurgical endodontic therapy of traumatized anterior teeth can result in a good prognosis in cases involving crown and intra-alveolar root fractures.     

Hardness comparison of bulk-filled/transtooth and incremental-filled/occlusally irradiated composite resins

STATEMENT OF PROBLEM: Use of a bulk-fill/transtooth composite resin insertion/irradiation technique may not provide as well polymerized a restoration as when using a conventional incremental placement/irradiation technique. Little information exists as to how the hardness of restorations produced by the 2 techniques compare. PURPOSE: The purpose of this study was to determine the effect of composite resin placement and an irradiation technique on the axial hardness at various depths in a Class I composite resin to include the influence of composite resin filler classification and shade. MATERIAL AND METHODS: Cylindrical Class I preparations were made in 70 recently extracted human molars and restored with either a light (A1) or dark shade (A4) of a microfill, microhybrid, or nanohybrid composite resin, or with a single shade of a translucent material. Half were placed using a conventional 2-mm-thick incremental-fill/occlusal irradiation technique, and half using a bulk-fill/transtooth irradiation method (n=5). Specimens were sectioned occluso-apically and axial Knoop hardness values were obtained at depths of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm. Hardness at 0.5 mm was used as a control to compare to deeper readings. Statistical analyses consisted of multiple ANOVAs and Dunnett's post-hoc tests performed at appropriately determined significance levels. RESULTS: For 3 multishaded materials tested, axial hardness values were relatively unaffected by composite resin shade or filler classification for the incremental technique, but were significantly affected by these factors when using the bulk-fill/transtooth irradiation method. A single shade translucent material was not affected in either the bulk or incremental condition. CONCLUSIONS: Use of a bulk-fill/transtooth irradiation technique for composite resin placement does not result in axial hardness values equivalent to that of an incremental-fill/occlusal irradiation technique.     

Value and significance of tooth mobility measurements]

1. The measurement of tooth mobility by manual and instrumental techniques is necessary for establishing a diagnosis, since it is of considerable importance for decisions in the framework of prophylaxis and therapy. 2. The significance of the measurement of tooth mobility depends upon the respective problem and the sensitivity of the measuring technique used. 3. The specifications for the precision of the measuring technique will be determined by the specific objective of the examination. 4. The instrumental measuring techniques are reproducible and, therefore, imperative in scientific studies.     

A clinical study of formocresol pulpotomy versus root canal therapy of vital primary incisors

OBJECTIVES: Pulpotomy of primary incisors is a serious challenge due to the lack of a distinct boundary between the coronal and the radicular pulp and the inaccuracy of the clinical indication criteria. The aim of the present study is the clinical and radiographic evaluation of pulpotomy versus root canal therapy (RCT) of vital primary incisors. STUDY DESIGN: A total of 100 incisors in 50 patients (female: 27, male: 23) aged 3-4 years were allocated to formocresol pulpotomy (45 teeth) and RCT (46 teeth) using zinc oxide-eugenol. The radiographic and clinical evaluation of treatment outcomes was performed at 12 and 24 months post-operatively. A history of spontaneous pain, missing restorations, recurrent caries, mobility and percussion sensitivity, parulis or fistula, erythema, and swelling were recorded. Data analysis was performed based on two sample proportional test. RESULTS: The clinical success rate was 86.9% for pulpotomy and 95.6% for RCT (P > 0.05). The radiographic assessment exhibited no pathologic signs in 76.08% of pulpotomy group and 91.3% of RCT group and the difference was statistically significant (P < 0.05). The most common pathologic finding was periodontal widening followed by external/internal root resorption. Periapical radiolucency and fistula in pulpotomized teeth was significantly higher than in RCT-treated teeth (P < 0.05) CONCLUSIONS: It may be concluded that the root canal therapy of vital primary incisors may be efficiently substituted for the pulpotomy of these teeth.     

Vital pulp therapy of mandibular incisors: a case report with 11-year follow up

This report describes a case of a young patient in whom all the mandibular incisor teeth suffered complicated crown fractures because of a car accident. For all mandibular incisors, pulpotomy with calcium hydroxide were performed in order to achieve apexogenesis and the teeth were restored with a double-seal of glass ionomer cement and composite resin. The patient was reviewed over 11 years. All the mandibular incisor teeth showed continued root development and complete apex formation. Pulp canal obliteration was observed in only the mandibular right central incisor.     

Color and translucency of in vivo natural central incisors

STATEMENT OF PROBLEM: The range of shades in shade guides is not consistent with natural teeth, and there is no information on the color and translucency of the natural tooth for all age groups. Therefore, it is important to obtain a database of the characteristics of the natural tooth from a wide age group. PURPOSE: This study obtained information on color and translucency of natural teeth for all age groups, and attempted to clarify the difference of the color and translucency between natural teeth and VITA Lumin Vacuum shade guide.Material and methods: Natural central incisors of 87 subjects (42 men and 45 women; age range from 13 to 84 years) and 16 shades of VITA Lumin Vacuum shade guide were evaluated. Color and translucency of 5 sites, each 1.0 mm in diameter, on the surfaces of individual teeth were measured for L*, a*, and b*, using a color computer according to CIELAB color spaces. RESULTS: At the center site, negative correlation was found between age and L*, with positive correlation between age and b*. Both a* and b* of the natural tooth increased when moving in the direction of the cervical site, but translucency decreased in the direction of the root. The a* value for the natural tooth was significantly higher than those for VITA Lumin Vacuum shade guide. CONCLUSION: This study found that the older the subject, the darker and more yellow the color at the center site of the natural tooth. Both reddish and yellowish colors of natural teeth tend to increase from the incisal to cervical, whereas translucency decreases. Red-green chromaticity of VITA Lumin Vacuum shade guide was not distributed to cover the natural tooth.     

Subjective and objective perception of upper incisors

The purpose of this study was to evaluate the subjective judgment (SJ) of patients on their own dental appearance and to correlate the results with objective measurements (OM) of their dentition concerning the appearance of the upper incisors. Seventy-five participants (30 men and 45 women) with normal well-being were included in the study. In a questionnaire they judged the appearance of their upper incisors. Furthermore, OM were evaluated by the investigator with regard to the following points: (i) absolute length of the upper central incisors, (ii) their length exposed during laughing, (iii) width-to-length ratio of central incisors and (iv) the proportion between the width of the lateral and central incisors. The subjective results were registered on visual-analogue scales. For the objective results standardized photographs were taken. No gender dependent differences could be found for the objectively measured parameters (median): OM1, 10.7 mm; OM2, 8.1 mm; OM3, 0.81; OM4, 0.79. However, significant correlations between subjective and objective results (SJ1/OM1, SJ2/OM2, SJ3/OM3) could be shown for men, but not for women. The maximum of the calculated regression-curves for men reflect 'golden standard values' well known from the literature. The degree of satisfaction concerning appearance of anterior incisors in accordance with golden standard values is higher for men than for women.     

Surgical treatment of ankylosed and infrapositioned reimplanted incisors in adolescents

Abstract – A method for preserving the alveolar ridge of ankylosed and infrapositioned incisors and improving conditions for a subsequent prosthetic therapy is described and evaluated clinically and radiographically. The method involves removal of the crown and root filling from the root, which is retained and covered with a mucoperiosteal flap. Clinically, there were no postoperative complications and after the follow-up a satisfactory prosthetic restoration was performed in all cases, regardless of the degree of infraposition before treatment. Radiographically, no pathologic changes were observed apart from a continuous resorption and replacement of lost root substance by bone. Alveolar bone level shifted only slightly between postoperative and 12-month follow-up radiographs, in a majority of cases in a coronal direction.     

Atypical extraction treatment for failing replanted maxillary and mandibular incisors with space closure of 2 mandibular incisors in the same quadrant

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