Radiographic Evaluation of Permanent Second Molar Substitution After Extraction of Permanent First Molar: Identifying Predictors for Spontaneous Space Closure

PURPOSE

The purpose of this study was to investigate pre-extraction variables associated with spontaneous space closure of the perma- nent second molar (PSM) following early extraction of the permanent first molar (PFM), and test an existing prediction model for the mandibular arch as the rates of spontaneous space closure are significantly lower in the mandible compared to the maxilla.

METHODS

Pre-extraction panoramic radiographs of 162 patients (138 maxillary and 168 mandibular quadrants) between five and 15 years old at the time of PFM extraction were evaluated. The prediction model was applied to the mandibular quadrants. Postextraction radiographic evaluation was used for outcome assessment, with success defined as the presence of a visible contact between the second premolar and PSM without marginal ridge discrepancy.

RESULTS

Success was observed in 82 percent of maxillary quadrants and 51 percent of mandibular quadrants. Maxillary PFM extraction between eight and 10 years or PSM Demirjian stage D or E demonstrated over 90 percent predictive probability for success. Mandibular PFM extraction at age eight years or PSM Demirjian stage D demonstrated 80 percent success. The prediction model did not add a more predictive value than chronological age or PSM Demirjian stage.

CONCLUSIONS

The prediction model was not validated in this study population. Chronological age and permanent second molar developmental stage were the primary predictors for successful substitution with the permanent second molar.

[Feasibility analysis of immediate implant placement in the maxillary molar region]

Objective: To study the clinical outcomes and feasibility of immediate implantation after flap surgery and minimally invasive extraction in the maxillary molar area and to provide a reference for it. Methods: Forty-one patients (41 molars in total) with maxillary molars that could not be preserved, treated from June 2018 to June 2020 at the Department of Oral and Maxillofacial Surgery at the Affiliated Hospital of Qingdao University, were selected. There are 24 males and 17 females with the age of (49.7±1.8) years (range 18-66 years). Pre-operative cone-beam CT (CBCT) was taken for measurement and analysis. After flap surgery and minimally invasive tooth extraction, the inflammatory granulation tissues attached to the soft and hard tissues were completely scraped and clipped, followed by the preparation of the implants in the correct three-dimensional position. Torque value and implant stability quotient (ISQ) were recorded after implant placement and with non-submerged healing. CBCT examination was taken 6 months after surgery and ISQ value was checked before crown restoration. CBCT examination was also taken 1 year after the permanent restoration. The survival rate of 6 months after surgery, the success rate of 1 year after permanent restoration, and the size of jump gaps immediately after surgery, 6 months after surgery, 1 year after permanent restoration respectively, were performed. The ISQ values were compared immediately and 6 months after surgery. Results: A total of 41 implants were placed in 41 patients. Six months after surgery, the survival rate was 100% (41/41). Twelve months after permanent restoration, the success rate of the implant restoration was 100% (41/41). The torque value after implant implantation was (42.77±0.79) N·cm. The buccal and palatal jump gaps were (3.15±0.16) mm and (2.86±0.18) mm immediately after surgery, respectively. The mesial and distal jump gaps were (2.94±0.19) mm and (3.77±0.21) mm, respectively. CBCT showed that no jump gap around the implants at 6 months after surgery and 1 year after permanent restoration. The ISQ values at immediately and 6 months after surgery were (74.78±0.59) and (80.20±0.49) respectively, and the difference was statistically significant (t=-9.03, P<0.001). Conclusions: Immediate dental implantation in the correct three-dimensional position could achieve good osseointegration by means of flap surgery, minimally invasive extraction and thorough removal of inflammatory tissue on the surface of soft and hard tissues. The clinical outcomes were satisfactory.

Cone beam computed tomography in the detection of reactional osteogenesis of the maxillary sinus: a case report

This report describes a case of reactional osteogenesis associated with the residual roots of the maxillary left first molar (tooth 14) in a 42-year-old woman. During intraoral examination, an extensive carious lesion was observed in the residual roots of tooth 14. On the periapical radiograph, a radiolucent area with well-defined limits and regular shape was observed in association with these roots. The 3-dimensional cone beam computed tomographic evaluation revealed that the hyperdense mass was homogenous, not corticated, of defined limits, and irregular in shape and had the density of bone tissue. The mass was clearly associated with an inflammatory periapical lesion. In this clinical case, volumetric analysis established a diagnosis of reactional osteogenesis and facilitated removal of the focus of infection associated with its development. Three-dimensional examination of possible changes in the maxillary sinus is crucial when infectious processes are present in the posterior region of the maxilla.

Guidance for Permanent First Molar Extraction in Molar-Incisor Malformation: Report of Two Cases

Molar-incisor malformation (MIM) is a newly described dental developmental anomaly that predominantly affects primary second molars, permanent first molars, and, in some cases, permanent central incisors. Diagnosis is usually made upon radiographic examination. The molars usually present with significant cervical constriction, flattened pulp chambers, and absent or thin, short, and narrow roots, whereas the incisors usually exhibit coronal dilaceration. Loss of these compromised teeth in the long term may be inevitable. Thus, clinicians should be aware of this condition and the factors to consider to advise their patients as early as possible. The purpose of this paper is to present two cases of MIM and discuss the factors clinicians should take into consideration to make a care plan in these cases.

Comparison of root canal shaping ability of different heat-treated NiTi single files: a micro-CT study

OBJECTIVE

The purpose of this study was to evaluate the root canal shaping abilities of different heat-treated NiTi engine--driven single files.

METHOD AND MATERIALS

A total of 45 mandibular first molar teeth with a root canal curvature of between 25 and 35 degrees were selected for this in vitro study. The mesial roots were separated and scanned with micro-CT. The specimens were randomly divided into three groups. Root canal preparations were performed using HyFlex EDM OneFile in Group 1; OneCurve (25/06) in Group 2, and WaveOne Gold Primary in Group 3. Root canals were scanned again with micro-- CT after root canal preparation. Apical transportation value and centering ability ratio of files were evaluated using the preinstrumentation and postinstrumentation micro-CT images at 1, 2, 3, 4, and 7 mm. The data were statistically analyzed using the Kruskal-Wallis test. The Bonferroni-Dunn test was used for multiple comparisons. The level of statistical significance was set at P < .05.

RESULTS

There was no significant difference between the apical transportation values of experimental groups in mesiodistal direction (P > .05) and buccolingual direction (P > .05). The OneCurve file group showed better centering ability in the buccolingual direction than the WaveOne Gold file group at 4 mm (P = .048). The difference between the centering ability values of experimental groups was not significant at other levels (P > .05).

CONCLUSION

According to the results of this study, all tested single files caused apical transportation and showed similar centering ratio at most of the root sections.

Impact of several NiTi-thermally treated instrumentation systems on biomechanical preparation of curved root canals in extracted mandibular molars

AIM

To evaluate the shaping ability of several heat-treated nickel-titanium systems used to prepare root canals with moderate and severe curvature, in extracted mandibular molars, by micro-computed tomography, considering their variation in kinematics and design.

METHODOLOGY

Curved-mesial roots of mandibular molars were randomly selected and assigned into 4 balanced experimental groups (n = 10), established by determining homogeneous 3D parameters of volume and surface area: R-Motion (RM) size 30, 0.04 taper (RM; FKG Dentaire), Reciproc Blue (RCB) size 25, 0.08 taper (RCB; VDW GmbH), HyFlex CM (HFX) size 30, 0.04 taper (HFX; Coltène Whaledent) and XP-endo Shaper size (XPS) 30, 0.01 taper (XPS; FKG Dentaire). The volume of irrigation was established at 10 ml of 2.5% NaOCl. Throughout the entire root canal preparation procedures, the samples were fixed in a vice submerged in a container with water monitored at 37°C. Dimensional cross-sectional measures of area, perimeter, roundness, major/minor diameters and 3-dimensional (volume, surface area, structure model index - SMI) parameters as well as the smallest dentine thickness along the cervical and middle root thirds were evaluated by micro-CT. Data were analysed using analysis of variance and post hoc Tukey tests (α = 5%).

RESULTS

Reciproc Blue and XPS had significantly greater mean increases in cross-sectional area measurements, only in the middle third, when compared with RM and HFX (p < .05). RM, RCB and XPS had a similar increase in measurements of length and width of perimeter (p > .05), and HFX had significantly lower mean increases in perimeter values only when compared with XPS (p < .05). RCB and XPS had significantly greater mean increases in volume when compared with RM and HFX (p < .05). RM had a significantly lower difference in SMI after preparation, compared with RCB, HFX and XPS (p < .05). The smallest dentine thickness was observed after the use of RCB (p < .05), in the danger and safety zones.

CONCLUSIONS

XP-endo Shaper and RM had a shaping ability similar to that of instruments with larger tapers, achieved with less dentine removal in danger and safe zones in curved-mesial canals of extracted molar teeth treated on a laboratory benchtop.

The effect of bone grafting on hard and soft tissue changes following immediate implant installation in mandibular molar sites

This study investigated the effect of bone grafting on hard and soft tissue alterations after immediate implant insertion in mandibular molar sites. This randomized, double-blind clinical trial consisted of 30 healthy patients (17 women and 13 men aged 22-58 years) who required immediate implant installation to replace a first or second mandibular molar. Only subjects with a buccal gap between 2 and 4 mm were selected. The participants were randomly allocated to two groups. In the experimental group, the gap was augmented by an allograft, whereas in the control group no graft was applied. Marginal bone level, probing depth, keratinized gingival width, and bleeding on probing were assessed at the time of implant placement (T0), 1 month (T1), and 3 months (T2) after surgery. There was no significant difference in hard and soft tissue parameters between the grafted and nongrafted sites at any of the durations (P < 0.05). Bone level decreased significantly in both groups (P < 0.05). However, the amount of probing depth and the frequency of cases showing bleeding on probing did not alter over the experiment either in the test or in the control group (P > 0.05). Bone grafting simultaneously with immediate implant installation had no significant effect on hard and soft tissue outcomes when the buccal gap size was between 2 and 4 mm. Therefore, the use of a bone substitute is not mandatory up to the jumping distance of 4 mm in immediate implant surgery.

A comparison of volume of tissue removed and biomechanical analysis of different access cavity designs in two-rooted mandibular first molars: a multi-sample three-dimensional finite element analysis

INTRODUCTION

The aim of this study was to compare the biomechanical properties and the amount of coronal tissue removed among the different access cavities with a multi-sample three-dimensional finite element analysis in mandibular first molar. The correlation between the amount of tissue removed and the fracture resistance of the teeth was also analysed.

METHODS

Micro-CT data from 20 two-rooted mandibular first molars were included in this study as three-dimensional modelling prototypes. The models of untreated molars and molars treated with the Traditional Access Cavity (TradAC), the Conservative Access Cavity (ConsAC) and the straight-line minimally invasive endodontic access cavities (SMIAC) were created. Each model was loaded in 3 ways to simulate the functional conditions of occlusion. The amount of tissue removed and the maximum stress in the cervical region were recorded and analysed, and the correlation between them was also analysed.

RESULTS

The amount of coronal tissue and peri-cervical dentin (PCD) removed in SMIAC and ConsAC was less than that of TradAC. The mean maximum stress in the cervical region was significantly smaller in SMIAC and ConsAC than in TradAC. The amount of hard tissue and PCD loss was positively correlated with the maximum stress in the cervical region of the tooth.

CONCLUSIONS

In mandibular first molars, it could be beneficial to improve the fracture resistance of the tooth after endodontic treatment by the minimally invasive access cavity to reduce the loss of coronal tooth tissue and PCD. The SMIAC may be an option balancing biomechanical properties and clinical convenience.

Alveolar Ridge Preservation in Severely Damaged Molar Socket Using a Polylactic Acid Membrane Without Primary Wound Closure: A Case Series

PURPOSE

Untreated severely damaged molar sockets often complicate implant placement. This study evaluated membrane degradation, soft tissue healing, and alveolar crest dimensional changes after alveolar ridge preservation (ARP) in severely damaged molar sockets using a polylactic acid membrane (PLA) and xenograft without primary wound closure.

MATERIALS AND METHODS

A total of 14 damaged molar sockets in 12 patients were grafted with deproteinized bovine bone mineral, which was covered with a PLA membrane without primary wound closure. Wound healing was evaluated at set times. Three sets of CBCT data taken before surgery, at 1 to 2 weeks, and at 6 to 12 months after surgery were reconstructed and superimposed to analyze dimensional changes of the alveolar crest with volumetric imaging software.

RESULTS

Two weeks after ARP, no degradation of PLA membrane was present, and the xenograft had either no exfoliation (7 sites, 50%) or mild exfoliation (6 sites, 42.9%). One to 2 months following ARP, the membrane was partially degraded in 6 sites (42.9%) and completely degraded in 8 sites (57.1%). Nine sites (64.3%) presented with mild graft particle exfoliation, and four sites (28.6%) had granulation tissue covering the bone graft. All sites were fully covered by keratinized mucosa by 6 to 12 months. Compared with baseline measurements, the vertical bone graft height decreased by 2.2 ± 2.2 mm, and central alveolar ridge thickness measured at the level of the virtual implant platform decreased by 5.0 ± 5.1 mm after 6 to 12 months.

CONCLUSION

The exposed PLA membrane maintains some barrier function for at least 3 to 4 weeks after ARP in severely damaged molar extraction sites. This technique allowed for implant placements without additional grafting. Future studies should include histologic assessment of the augmented bone and nongrafted control sockets.

Initial Change in the Occlusal Force and Occlusal Contact Area Following Single Molar Implant Restoration

PURPOSE

The occlusal force and occlusal contact area may be used to evaluate oral function following restoration of a missing tooth. This study aimed to monitor the initial changes in these factors after single molar implant restoration.

MATERIALS AND METHODS

Patients who underwent single implant restoration between December 2018 and September 2019 were recruited for this study. Occlusal force was measured before, immediately after, and 1 month after prosthesis placement. The occlusal contact area was evaluated immediately and 1 month after the placement. Data were grouped by sex, restored tooth, and restored side for analysis.

RESULTS

In most groups, occlusal force was significantly increased 1 month after the placement compared with that before placement (P < .05), and the change was more significant in the first molar group than in the second molar group. There was a significant difference in the occlusal contact area of the implant prosthesis immediately and 1 month after placement when a thickness of 9 μm was used. The occlusal contact area of the natural tooth in the mesial side was significantly increased 1 month after placement (P < .05).

CONCLUSION

Occlusal force was significantly increased 1 month after implant restoration, and restoration of the first molar had the most significant effect on the occlusal force. Occlusal contact areas may differ according to the occlusal indicator used in the clinical setting because the changes were significant with only 0 to 9 μm.

The added benefit of L-PRF to autogenous bone grafts in the treatment of degree II furcation involvement in mandibular molars

BACKGROUND

Tissue regeneration within the periodontally involved furcation area is one of the most challenging aspects of periodontal surgery. The aim of this study was to evaluate the additional benefit of leukocyte and platelet-rich fibrin (L-PRF) to autogenous bone grafts (ABGs) in the treatment of mandibular molar degree II furcation involvement, comparing the clinical outcomes with those from open flap debridement (OFD)+ABG and OFD alone treatments.

METHODS

Fifty-four patients, exhibiting one buccal or lingual mandibular molar furcation defect, were randomly assigned to three treatment groups: OFD+ABG+L-PRF(n = 18); OFD+ABG (n = 18); and OFD (n = 18). Clinical [probing pocket depth (PPD), horizontal clinical attachment level (HCAL), vertical clinical attachment level (VCAL), gingival recession (GR)] and radiographic [vertical bone level (VBL)] parameters were evaluated at baseline and 6 months after treatment. HCAL change was the primary outcome.

RESULTS

No significant differences within each group were reported for GR changes, but statistically significant improvements in HCAL, VCAL, PPD and VBL were observed in all groups, except for VBL in the OFD group. At 6 months, the mean HCAL gain was 2.29±0.18 mm in the OFD+ABG+L-PRF group, which was significantly greater than that in the OFD+ABG (1.61±0.18 mm) and OFD (0.86±0.18 mm) groups. Both OFD+ABG+L-PRF and OFD+ABG therapies produced a significantly greater clinical and radiographic improvement than OFD.

CONCLUSION

The addition of L-PRF to ABG produces a significantly greater HCAL gain and PPD reduction as compared to OFD+ABG treatment in mandibular degree II furcation involvements. This article is protected by copyright. All rights reserved.

Management of ectopically erupting permanent molars in a seven-year-old girl: A case report

Ectopic eruption of permanent first molar is a developmental disturbance, leading to many local problems, such as premature loss of the second primary molars, space loss, increased prevalence of dental caries, supraeruption of the opposing molars, mesial inclination of the permanent maxillary first molars and class II molar relationship. We report the case of a seven-and-a-half-year-old girl with ectopic eruption of permanent maxillary and mandibular first molar, treated by orthodontic separators and slicing the distal surface of the adjacent primary second molar separately. Regular examination and timely interception are important during oral health management of children and is of great significance in alleviating the side effects of ectopic eruption.

Endodontic Treatment of a Molar with Peculiar Anatomy: Case Study with CBCT and 3D Printed Model

AIM

The aim of the study was to achieve the endodontic treatment of a second maxillary molar with abnormal anatomy through cone-beam computed tomography (CBCT) analysis and three-dimensional (3D) printing.

BACKGROUND

A patient arrived referring recurrent abscesses, spontaneous pain, and the difficulty to eat properly; a diagnosis of tooth necrosis was made. The periapical X-ray showed an abnormal anatomy of the tooth.

CASE DESCRIPTION

The preoperative analysis of the tooth morphology was performed through CBCT analysis. The 3D scans were reconstructed through a dedicated software application (Mimics) to visualize the abnormal anatomy and detect the root canal morphology. Moreover, a 3D printed model was created to plan the clinical stage. Canal shaping was achieved with ProGlider and ProTaper Next techniques, and the root canal filling was performed with a carrier-based technique.

CONCLUSION

The limits of this case were the low definition of the CBCT owned by the patient and the difficulties during the scouting of the canals due to the abnormal endodontic space complicated by narrow and flat canals. The software reconstruction allowed a 3D high-definition preclinical analysis of the tooth anatomy.

CLINICAL SIGNIFICANCE

Both digital analysis and printed models based on CBCT scans seemed fundamental to preclinically understand the abnormal endodontic anatomy.

Preliminary Results of a Minimally Invasive Microsurgical Approach to Sinus Floor Elevation and Bone Reconstruction Using a Palatal Septum Window

The aim of this case report was to present the preliminary results of a novel microsurgical approach to sinus floor elevation and bone augmentation. This technique was used to treat four patients in whom an implant could not be placed in the maxillary first molar position because of insufficient bone height. The maxillary first molar was extracted, and a sinus access window was created in the palatal area of the bony interradicular septum. The sinus membrane with the palatal septum fragment was elevated, and the sinus space between and above the roots was filled with xenograft. Alveolar preservation was done with xenograft and a nonresorbable membrane. Bone augmentation was evaluated 6 months after preservation by computed tomography and histology; clinical, radiologic, and histologic bone reconstruction were seen, allowing placement of implants. The novel approach utilized in this study demonstrated positive preliminary results in bone reconstruction with reduced morbidity.

LSTR Antibiotic Paste Versus Zinc Oxide and Eugenol Pulpectomy for the Treatment of Primary Molars with Pulp Necrosis: A Randomized Controlled Trial

Purpose: The purpose of this study was to compare the effectiveness of lesion sterilization and tissue repair (LSTR) antibiotic paste comprised of chloramphenicol, tetracycline, and zinc oxide and eugenol (CTZ) versus zinc oxide eugenol (ZOE) pulpectomy in the treatment of primary molars with pulp necrosis. Methods: A total of 70 three- to eight-year-old subjects with 88 primary mandibular molars with pulp necrosis were included. The teeth were randomized to the CTZ group or ZOE group. The time taken to perform both techniques was recorded. The parents of the children and the dentist who performed clinical evaluations were blind to the group assignment, although the radiographic evaluator could see the difference in treatments. Clinical and radiographic assessments were performed at three, six, nine, and 12 months. Results: At the 12-month evaluation, the clinical success was 86.4 percent for CTZ and 90.9 percent for ZOE (P=0.50), the radiographic success was 75.0 percent for CTZ and 72.7 percent for ZOE (P=0.81), and the overall success was 70.5 percent for CTZ and 72.7 percent for ZOE (P=0.81). The mean time taken to perform was 61.4 (±20.5 standard deviation) minutes for CTZ and 145.1 (±53.2) minutes for ZOE (P<0.001). Conclusions: At 12 months, both techniques presented no significant difference in success rates for nonvital pulp therapy in primary molars with necrosis. The lesion sterilization and tissue repair procedure time using chloramphenicol, tetracycline, zinc oxide, and eugenol was significantly shorter than for a zinc oxide eugenol pulpectomy.

Early replacement of ankylosed first molar via mesial root movement facilitates bone formation and normal eruption of the third molar

Ankylosis of a molar during active growth leads to a significant vertical bone defect, extrusion of the opposing molar, and inclination of adjacent teeth. Treatment timing is an essential factor for the patient's quality of life. Early extraction of the ankylosed molar and protraction of the second molar is challenging because of the difficulty of tooth movement and the uncertainty of the normal eruption of the third molar. In view of the uncertainty of eruption of the mandibular third molar, it is essential to assess the potential for eruption according to the developmental stage of the third molar and to secure sufficient space for eruption. In this case report, a girl with an ankylosed right mandibular first molar and an advanced vertical bone defect was treated via early extraction of the ankylosed molar along with the intrusion of the maxillary molar and mesial root movement of the second molar before the initiation of third molar root formation. Restoration of the vertical bone defect was noted at the end of treatment. In addition, spontaneous eruption of the third molar was observed, which was in contrast to the mesioangular impaction of the contralateral third molar. This case emphasizes the importance of treatment timing to increase the chance of utilization of the third molar.

Efficacy of type-1 collagen cones in extraction sockets following surgical removal of semi-impacted mandibular third molars: a randomized controlled trial

OBJECTIVES

Third molar extractions may affect the periodontal health of the adjacent second molars as well as the patient's comfort. The objective of this study was to evaluate the efficacy of type-1 collagen cone (CC) on periodontal health and postoperative sequelae following extraction of third molars with secondary healing.

METHOD AND MATERIALS

This was a randomized, controlled, split-mouth clinical trial. Sixty mandibular third molars (30 patients) were subdivided according to side. A collagen cone was randomly inserted into one side and the other side was the control. Pain was evaluated using a visual analog scale. Trismus and facial swelling were determined on postoperative days 2, 7, and 30. The alveolar osteitis (AO) incidence was recorded on days 2 and 7. The Plaque Index, Gingival Index, clinical attachment level, and pocket probing depth of the second molars were evaluated at postoperative months 1, 3, and 6.

RESULTS

No significant differences were found between groups regarding postoperative pain, trismus, facial swelling, or the incidence of AO. However, AO developed in 10% of control side cases, while no sign of AO was observed on the experimental side. Plaque Index, Gingival Index, and clinical attachment level were comparable in both groups. Pocket probing depths for the distobuccal surface of the second molar was significantly higher on the control side at 6 months (P = .017).

CONCLUSION

Insertion of a type-1 collagen cone into an extraction socket did not show a significant clinical improvement in extraction socket healing and postoperative sequelae after the third molar extraction.

Immediate Loading of Straumann® TLX Implant in Grafted Maxillary First Molar Site

The patient treatment described in this case report demonstrates management of a failing maxillary first molar utilizing an immediate loading approach. Following extraction, the site was successfully managed with socket grafting (ridge preservation) and allowed to heal prior to implant placement. A Straumann® TLX implant was placed using a guided approach and restored using CAD/CAM.

Primary Second Molar Treatment as a Predictor of Repeat General Anesthesia

Purpose: The purpose of this study was to investigate an association between treatments on the primary second molars (PSMs) under general anesthesia (GA) and odds of repeat GA. Methods: This was a retrospective study of children who received dental treatment under GA between the ages of 24 to 48 months. Descriptive statistics and logistic regression models (P<0.05) were used to test the association between the treatment of PSMs at the first dental GA visit (GA1) and the odds of receiving GA a second time (GA2) within the next 55 months post-GA1. Results: A total of 819 children (53 percent male) with a mean (±SD) age of 36 (±seven SD) months and 3,276 PSMs were included. Only three percent of children with all PSMs covered at GA1 received GA2. The odds of GA2 significantly increased for children with any uncovered PSMs. Among children with four uncovered PSMs, 19 percent (odds ratio [OR] equals 13; 95 percent confidence interval [95% CI] equals 5.8 to 33.5; P<0.001) and among those with unerupted PSMs at GA1, 51 percent received GA2 (OR equals 62.9; 95% CI equals 23.5 to 189.2; P<0.001). In the group that received GA2, 79.1 percent of uncovered PSMs at GA1 eventually received a stainless steel crown at GA2. Conclusions: Restorative treatments other than stainless steel crowns were associated with higher odds of repeat general anesthesia. These findings support the preferential use of full-coverage restorations for the treatment of carious primary molars in young children undergoing GA to minimize the risk of the need for repeat GA.

Double Gemination or Fusion of a Permanent Mandibular Second Molar: A Case Report

Gemination and fusion are developmental conditions affecting the shape of teeth in both primary and permanent dentition. A 12-year-old girl presented for clinical assessment and the examination revealed an unusually shaped mandibular right second molar with irreversible pulpitis. Correlation of the intraoral and radiological appearance of this tooth suggested a diagnosis of either double gemination or fusion. The favourable position of the developing third molar supported early extraction of the abnormal second molar. The present report documents the clinical and radiological presentation of a mandibular second molar with an unusual developmental alteration in shape. Well-timed extraction therapy and good communication may reduce the need for unnecessary, complex treatment.

Clinical and Radiographic Assessments of Potassium Nitrate in Polycarboxylate Versus Mineral Trioxide Aggregate as Pulpotomy Biomaterials in Immature Mandibular First Permanent Molars: A Randomized Clinical Trial

INTRODUCTION

The purpose of this study was to compare clinically and radiographically the effects of potassium nitrate in polycarboxylate cement and mineral trioxide aggregate (MTA) as pulpotomy agents in vital immature mandibular first molars.

METHODS

The trial design was a parallel randomized, 1:1 allocation ratio, with both the participants and the data assessor blinded. A total of 50 molars of 48 eligible children aged 6-9 years were studied. The children had mandibular immature first molars with extensive caries that revealed pulp exposure during caries excavation. Patients were randomly allocated equally into 2 groups in which potassium nitrate in polycarboxylate cement (the intervention group) and MTA (the control group) were used as pulpotomy biomaterials. The treated teeth were restored permanently. The primary outcome was clinical/radiographic assessment after 1 week, 6 months, and 12 months. The secondary outcomes were radiometric analysis at 6 and 12 months to determine dimensional changes during maturogenesis. The digital radiographs were imported to image processing software to perform radiometric measurements. Data were tabulated and statistically analyzed with significance set at P ≤ .05.

RESULTS

Only a single tooth failed at the 6-month recall, and another one was lost during recall in each group. Thus, the overall success rate for cases/group who finally attended the 12-month follow-up time point was 92% (23/25) with no statistically significant difference between the 2 groups. At the 12-month recall, successful cases showed root development with an increase in root length and a decrease in apical foramen width. Complete apical closure was observed in 65.2% of the roots in the intervention group and 52.1% in the control group.

CONCLUSIONS

The clinical and radiographic success reported in the present study reveals that potassium nitrate in polycarboxylate cement could be used as a biological and economic alternative to MTA as a pulpotomy agent in vital immature mandibular first molars. Further follow-up for longer periods is recommended.

CLINICAL AND RADIOGRAPHIC CHANGES FOLLOWING ORTHODONTIC INTRUSION OF OVERERUPTED MAXILLARY MOLARS WITH TWO MINI-IMPLANTS

Objective - to evaluate clinical and radiographic changes of orthodontic intrusion of upper first molars with two mini-implants, using light intrusion forces, to create the space for prosthetic rehabilitation on the lower jaw. In 20 patients (aged between 26.8 and 45) with secondary deformities in the lateral region in the vertical direction, associated with partial absence of teeth in the lower jaw, and orthodontic preparation for subsequent prosthetics was performed. Each subject was missing 1-2 teeth in the lateral segment. All patients were divided into two groups: with intrusion mechanics with orthodontic implants (20 people) and intrusion with an orthodontic shape memory arch (20 people). The radiographic changes in male and female groups were assessed and compared based on the panoramic radiographs and CBCT data before and after intrusion. In the study 28 molars were fully intruded and their position was normalized with two mini-implants placed palatally and buccally. Mean extrusion time was 7.86±0.42 months (P<0.001), mean intrusion length was 2.97±0.15 mm (P<0.001), and mean change of mesial molar inclination was 2.02±0.44 degrees (P<0,005). The degree of root resorption was evaluated according to CBCT data in Multiplanar reconstruction (MPR); 50% of molars had grade 0 of resorption, 42.85% had grade 1, and 7.15% of molars had grade 2. There was no resorption in the trifurcation area. Intrusion of molars can be successfully accomplished with 2 mini-implants, placed palatally and buccally, with a light traction force (30-50 g) of an elastic chain.

Occlusal stress distribution in the human skull with permanent maxillary first molar extraction: A 3-dimensional finite element study

INTRODUCTION

The objective of this research was to analyze the effect of orthodontic treatment with maxillary permanent first molar extraction on the occlusal stress distribution and displacement in the human skull.

METHODS

A 3-dimensional finite element model was constructed on the basis of a computed tomography scan, and it was used as the pretreatment model. The software used for geometric modeling was Solid Works (Dassault Systèmes, Paris, France). For the extraction model, the maxillary permanent first molar was removed, followed by a repositioning of the anterior and posterior segments to create a space closure model. Stress distribution was evaluated under the simulation of 1000 N for occlusal forces and 400 N for masseter muscle force.

RESULTS

The highest von Mises stress was observed at the zygomatic process of the temporal bone across all 3 models (25 MPa), whereas stress at the pterygomaxillary suture area was almost 50% less. However, the stress in the pterygomaxillary suture area was lowest in the extraction model (18%) and space closure (30%). Stress in the zygomatic process of the frontal bone and frontal process of the maxilla increased from pretreatment to extraction model followed by space closure model.

CONCLUSIONS

The occlusal forces were transferred through maxillonasal, maxillozygomatic, and maxillopterygoid stress trajectories. The mesial displacement of the molars may weaken the role of maxillopterygoid stress trajectory while strengthening the role of maxillonasal stress trajectory.

Influence of Minimally Invasive Access Cavity Designs on the Fracture Resistance of Endodontically Treated Mandibular Molars Subjected to Thermocycling and Dynamic Loading

INTRODUCTION

The aim of this study was to investigate the fracture resistance of endodontically treated and restored permanent mandibular molars with minimally invasive access cavities subjected to thermocycling and dynamic loading.

METHODS

Forty first and second mandibular molars were randomly assigned to 4 groups (n = 10/group) as follows: group 1, control (intact teeth); group 2, traditional access cavity (TradAC); group 3, conservative access cavity (ConsAC); and group 4, truss access cavity (TrecAC). After endodontic treatment, teeth were restored with SDR core (Dentsply Caulk, Milford, DE) and subjected to thermocycling followed by dynamic and static loading with a multiaxial fatigue testing machine (Instron, Canton, MA). The maximum load to fracture and pattern of failure (restorable/unrestorable) were recorded. Data were evaluated with analysis of variance and the Tukey post hoc test for multiple comparisons.

RESULTS

Fracture resistance of the samples in the control group were higher than those in the experimental groups (P < .005). TradAC exhibited the least resistance to fracture (P < .005). There was no statistically significant difference in the fracture resistance of ConsAC and TrecAC (P = .361) Unrestorable fractures were more frequent in the TradAC group compared with all other groups.

CONCLUSIONS

Mandibular molars with ConsAC and TrecAC exhibited superior fracture resistance compared with TradAC. TradAC had the highest number of unrestorable fractures.

A Comparative Evaluation of Sealing Ability of Five Different Materials for Furcation Perforation Repair Using UV-Spectrophotometric Analysis: An In-Vitro Study

This in-vitro study was done to compare the sealing ability of Mineral trioxide aggregate (MTA), Biodentine, a mixture of MTA and Glass ionomer cement (GIC) in 2:1 and 1:1 ratio and MTA CEM, as furcation repair material using a dye extraction leakage model in the department of Conservative Dentistry and Endodontics from January 2020 to December 2020. Eighty five extracted molars with divergent and well formed roots were selected for study and were randomly divided according to the material used for perforation repair. Group A: MTA, Group B: Biodentine, Group C: MTA mixed with GIC in 2:1 ratio. Group D: MTA mixed with GIC in 1:1 ratio. Group E: MTA CEM and 2 control groups. All samples were subjected to orthograde and retrograde methylene blue dye challenge followed by dye extraction with 70 weight % nitric acid. Samples were then analyzed using Ultra violet (UV) Visible Spectrophotometer at 550nm wavelength. The data were subjected to statistical analysis One Way ANOVA (level of significance <0.05) and post-hoc tukey test. MTA, Biodentine, Mixture of MTA and GIC in 2:1 ratio and MTA CEM showed significant less dye absorbance than MTA and GIC in 1:1 ratio. Within the limitation of the study, the newer mixture of MTA and GIC in 2:1 ratio showed promising sealing ability and was comparable to MTA, Biodentine and MTA CEM.

Peri-implant tissue stability in premolar and molar sites: a retrospective clinical and radiographic analysis

OBJECTIVES

The retrospective study was undertaken to assess the peri-implant tissue stability in premolar and molar sites clinically and radiographically for implants 7 years after loading.

METHOD AND MATERIALS

408 implants placed in 275 patients from 2012 to 2020 and following a regular recall protocol were assessed for Modified Plaque Index (MPI), Sulcus Bleeding Index (SBI), pocket probing depth (PPD), and the peri-implant soft tissue dehiscence (PSTD) clinically and mesial bone loss (MBL) and distal bone loss (DBL) radiographically.

RESULTS

Significant differences were found in MPI, SBI, and PPD amongst both men and women in the premolar and molar regions. The mean MBL and DBL were substantially greater in women than in men and marginally more in the maxilla than in the mandible. Maximum mean bone loss on either aspect of the premolar and molar implants was 2.80 ± 1.54 mm and 2.97 ± 0.96 mm for women. Implant success of 96.82% at 7 years was achieved and the patient satisfaction levels of 94.55% and 95.50% in the mandibular and maxillary arches, respectively, implied that patients were satisfied with the treatment.

CONCLUSION

Women exhibited greater marginal bone loss on the mesial and distal aspects than men, with premolar implant sites demonstrating greater propensity for marginal bone loss than molar implant sites.

Assessment of Clinical and Radiographic Success Rate of Formocresol-based Pulpotomy versus Collagen-based Pulpotomy: An In Vivo Study

AIM

The aim of the study is (a) To use collagen as a pulpotomy material in comparison with the gold standard formocresol-based pulpotomy, (b) to assess the clinical and radiographic success rate of formocresol pulpotomy and collagen-based pulpotomy, and (c) to compare the success rate of formocresol-based pulpotomy and collagen-based pulpotomy over a definitive interval of time.

MATERIALS AND METHODS

Totally 30 primary first or second molars indicated for pulpotomy after confirming with the operative diagnosis were taken as samples for this study. This split-mouth technique consists of two groups: Group 1-formocresol pulpotomy (n = 15), and group 2-collagen-based pulpotomy (n = 15). Both the procedures were done in the same patient on regular appointments. Pre- and postoperative radiographs were taken. The children were recalled for clinical and radiographic follow-up at 2, 4, and 6 months. The success of the procedure was assessed based on clinical signs (pain, tenderness to percussion, abscess, swelling, fistula, and pathologic mobility) and radiographic findings (radicular radiolucency, internal and external root resorption, periodontal ligament (PDL) space widening, and furcation radiolucency). The Chi-square test was used to compare the differences between the groups.

RESULT

The overall success rate for formocresol pulpotomy (n = 15) was 14, 13, and 10 for the second-, fourth-, and sixth-month review period, respectively. For collagen pulpotomy group (n = 15), the overall success rate was 14, 14, and 14 for the second-, fourth-, and sixth-month review period, respectively. The obtained data from the overall success rate were subjected to statistical analysis, and chi-square test was used. The p-value less than 0.1 was considered a statistically significant result. The chi-square value for the fourth- and sixth-month review was 0.37 and 3.33, respectively.

CONCLUSION

Statistically significant value was obtained from the sixth-month review period (p <0.1), which describes that the overall success rate was better for the collagen pulpotomy group when compared with the formocresol pulpotomy group.

CLINICAL SIGNIFICANCE

Collagen had proven to be a very good alternative for formocresol, its biocompatibility, and regenerative efficiency and is a benchmark for a better clinical success rate in dentistry. However, its implication in pulpotomy should be subjected to further comparative research study on mineral trioxide aggregate (MTA), Biodentine, etc. Keywords: Collagen-based pulpotomy, Formocresol-based pulpotomy.

Effect of Apical Third Enlargement to Different Preparation Sizes and Tapers on Postoperative Pain and Outcome of Primary Endodontic Treatment: A Prospective Randomized Clinical Trial

INTRODUCTION

The purpose of this study was to evaluate the effect of apical preparation size and taper on postoperative pain and healing after primary endodontic treatment.

METHODS

One hundred and twenty patients with asymptomatic mandibular first molars with radiographic evidence of periapical pathology and with a periapical index (PAI) score ≥3 were randomly assigned to 2 groups, group 1 and 2, based on apical enlargement to 2 and 3 sizes larger than the initial apical binding file (IABF), respectively. Each group was further divided into subgroups A and B depending on the apical enlargement taper of 4% and 6%, respectively. Endodontic treatment was performed, and the final apical enlargement in all the groups was performed as follows: group 1A, 2 sizes larger than the IABF with a 4% taper; group 1B, 2 sizes larger than the IABF with a 6% taper; group 2A, 3 sizes larger than the IABF with a 4% taper; and group 2B, 3 sizes larger than the IABF with a 6% taper. Postoperative pain was assessed at 6, 12, 24, 48, and 72 hours. Clinical evaluation and the change in the PAI score on radiographs were assessed at the 3-, 6-, and 12-month follow-ups.

RESULTS

No significant difference in postoperative pain was found. The success rate was lowest (57.1%) in group 1 subgroup A as evidenced by the significant change in the PAI score between group 1 subgroup A and the rest of the groups at the 6- and 12-month follow-ups.

CONCLUSIONS

Apical preparation to 2 sizes larger than the IABF with a 4% taper is insufficient and results in significantly lower success rates compared with larger preparation sizes and tapers.

One year clinical success of pulpectomy in primary molars with iodoform-calcium hydroxide paste

OBJECTIVES

In order to retain primary molars, eg with irreversible pulpitis or pulp necrosis, pulpectomy can be an alternative to extraction. However, reports on the success of pulpectomies in primary teeth vary widely in the literature. Thus, the objective of this study was not only to analyze the success rate of primary tooth pulpectomy 12 months posttreatment in the setting of a specialized clinic, but also to identify and analyze various factors that modify the outcome.

METHOD AND MATERIALS

Between 2012 and 2018, a total of 76 dental records of the Department of Preventive and Pediatric Dentistry at the University of Greifswald fulfilled the inclusion criteria, resulting in a 1-year analysis of 62 primary molars with an idoform-calcium hydroxide paste as root canal filling material almost exclusively covered by a stainless steel crown as restoration.

RESULTS

The pulpectomy treatment was successful after 1 year in 93.5%, with a significantly higher survival for mandibular primary molars (100.0% vs 83.3%; chi-square test P = .01). Apart from the very few cases in the mixed dentition, no other factors related to the patient (sex, caries level, general health conditions, distance to clinic), tooth (first or second primary molar, pulpal and periapical condition before treatment), or treatment (indication, academic qualification of the operator, number of visits) proved to be of significance for the treatment outcome due to the overall high success rate.

CONCLUSION

Pulpectomies for pulpally involved or even necrotic primary molars followed by stainless steel crowns as restoration should be considered as a treatment option, especially in the mandible. (Quintessence Int 2021;52:528-537; doi: 10.3290/j.qi.b1244443).

Sealing Socket Abutments (SSAs) in Molar Immediate Implants with a Digitalized CAD/CAM Protocol: Soft Tissue Contour Changes and Radiographic Outcomes After 2 Years

Immediate implant placement in molar sites has the potential to improve the patient experience by reducing the number of appointments and the overall treatment time. However, primary closure remains a technical challenge. The present prospective case series evaluated the soft tissue contours and the radiographic bone levels of 17 patients who received immediate implants in molar sites and a digitally customized CAD/CAM sealing socket abutment. At the 2-year follow-up, the mean buccal tissue contours at the most coronal portion were reduced horizontally by an average of 1 mm at 1, 2, 3, and 4 mm below the gingival margin. A mean 0.53-mm apical migration of the gingival margin was seen, and the mean interproximal bone level at the 2-year follow-up was 0.89 mm. The use of CAD/CAM-generated customized healing abutments in immediate molar sites yielded minimal hard and soft tissue changes at the 2-year follow-up.

Alveolar Ridge Preservation on Maxillary Molars Using Solvent Dehydrated Bone Allograft and d-PTFE Membrane: A CBCT and Histologic Human Pilot Study

The purpose of this study was to evaluate vertical and horizontal alveolar resorption after the extraction of eight single maxillary molars using solvent-dehydrated bone allograft (Puros) covered with a nonresorbable membrane for ridge preservation. At implant placement 4 months later, ridge dimensions were measured clinically and radiographically and compared to baseline, and a histologic analysis was performed. The mean buccal height decreased by 1.51 mm at midpoint, 0.88 mm mesially, and 1.16 mm distally. The implants were placed without additional ridge augmentation, and six of eight required an internal sinus elevation. Within the limits of this study, this technique succeeded in preserving the alveolar bone.

Socket Preservation Following Extraction of Molars with Severe Periodontitis

The efficacy of the socket preservation procedure using deproteinized bovine bone mineral, bioabsorbable collagen membrane, and collagen sponge on molar extraction sites with severe periodontitis was assessed at 6 postoperative months, before implant placement. Results revealed excellent soft tissue healing without loss of keratinized tissue and no statistically significant differences in socket marginal bone changes in 20 molar extraction sockets. High levels of primary implant stability were recorded. Socket preservation using a minimally invasive surgical technique provides good soft and hard tissue healing as well as anticipated stability of implant placement at sites of extracted molars with severe periodontitis.

Comparison Of Anaesthetic Efficacy Of Articaine And Lidocaine In Nonsurgical Endodontic Treatment Of Permanent Mandibular Molars With Symptomatic Irreversible Pulpitis. A Randomized Clinical Trial

BACKGROUND

Inferior Alveolar Nerve Block (IANB) with Buccal Infiltration (BI) anaesthesia is required to completely anesthetize the mandibular molars with symptomatic irreversible pulpitis. 4% Articaine and 2% Lidocaine provide local anaesthesia during the nonsurgical endodontic treatment of mandibular molars with symptomatic irreversible pulpitis. Objective of the study was to compare the effect of Articaine and Lidocaine in the combination of Inferior alveolar nerve block with buccal infiltration anaesthesia during the nonsurgical endodontic treatment of mandibular molars with symptomatic Irreversible Pulpitis.

METHODS

One hundred and sixty participants with Symptomatic Irreversible Pulpitis of permanent mandibular molars were divided randomly in two groups. Group A was given Articaine 4% IANB along with BI whereas group B was given Lidocaine 2%. Pain was assessed after 15 minutes of administration of local anaesthesia. Anaesthetic success of the agents is defined as, absence of pain or mild pain first during the access cavity preparation then instrumentation of the canals of tooth. Chi-square test was applied to analyse data for statistical significance.

RESULTS

Anaesthetic success of Articaine was 96.2% during access cavity preparation compared to Lidocaine (86.2%). Success during instrumentation of canals was also found to be high in Articaine (90.2%) compared to Lidocaine (76.2%). This difference of anaesthetic efficacy between Articaine and Lidocaine was found statistically significant. (p=0.02).

CONCLUSIONS

Articaine is found to be better than Lidocaine regarding anaesthetic efficacy and hence, it can be a safer alternative to Lidocaine.

Root Microcracks Formation during Root Canal Instrumentation Using Reciprocating and Rotary Files

AIM AND OBJECTIVE

The aim of this study was to compare the formation of dentinal cracks with nickel-titanium (NiTi) instruments working in continuous rotation and reciprocating motion.

MATERIALS AND METHODS

One hundred sixty extracted human mandibular first molars were selected for the study. The mesial roots were resected and mounted in resin blocks with simulated periodontal ligaments. Those teeth were randomly assigned to five groups (n = 32 teeth/group). The first one was treated with K-files and served as control group, and the remaining 128 teeth were divided into 4 groups depending on the root canal preparation technique. Group 2 samples were prepared by sequential ProTaper Universal (PTU), group 3 samples with rotary ProTaper Universal (RPTU), group 4 achieved by the One Shape (OS), and group 5 with the WaveOne (WO) primary files. Roots were then horizontally sectioned at 3, 6, and 9 mm from the apex, and the slices were then observed under a stereomicroscope at ×40 magnification to determine the presence of internal dentinal microcracks. The presence or absence of dentinal defaults was recorded and the statistical analysis was performed by Pearson Chi-square test. The significance level was set at p < 0.05. The study was made in the oral biology and biotechnology research laboratory of the faculty of medical dentistry of Rabat, Morocco.

RESULTS

No dentinal defect was seen with the stainless steel hand file (group 1). The manual PTU (group 2), the RPTU (group 3), the OS (group 4), and the WO (group 5) in reciprocating motion caused cracks in 15.6%, 12.4%, 21.9%, and 6.2% of samples, respectively. The highest percentage of dentinal defect was showed in group 4 but without significant difference with the other group (p > 0.05).

CONCLUSIONS

Dentinal cracks are produced indifferently of motion kinematics. Within the limits of this study and the current literature, such incidence is less with instruments working in reciprocating motion compared with those working in continuous rotation. Manual and rotary NiTi sequential systems showed fewer microcracks than the single file system working by continuous rotation motion.

Revisit incidence of complications after impacted mandibular third molar extraction: A nationwide population-based cohort study

Most of complications after impacted mandibular third molar (iLM3) extraction surgeries are transient and resolved spontaneously within one or two weeks, but some of them are more complicated and required further treatments to alleviate the symptoms. The aim of study is to revisit incidence and predictors of complications after iLM3 surgery by reviewing previous literature and investigating a population-based data. From Taiwan National Health Insurance Research Database, records of 16,609 patients who had received iLM3 extraction under ambulatory settings were retrieved for analysis. Outcomes of interest included dry socket (DS), prolonged temporomandibular joint symptoms (TMD), and surgical site infection (SSI), which necessitated additional appointments to manage. Odds ratios of having those complications between different variables were analyzed. The incidence rates of DS, TMD, and SSI were 3.6%, 0.41%, 0.17%, respectively; while they ranged from 0.33–19.14% (DS), 0–4.17% (TMD), and 0.2–5.17% (SSI) in previous studies. Logistic regression revealed DS significantly correlated with complexity of odontectomy (2.5-fold of risk) and history of gingivitis or pericoronitis (1.3-fold of risk). More TMD was found in female than male patients (0.5% versus 0.3%). However, no factors associated with SSI was found; neither did we find aging as a risk in association with any of above complications. Compared to previous studies, our data supports that surgical intervention should be considered in iLM3 with risk of gingivitis or pericoronitis to reduce the occurrence of DS. The original information in this article, which provides a “real-world” evidence, along with the organizing data we summarized from previous article, can serve as a reference for clinicians in assessing the complication risks before treatment of iLM3.

Survival of molar teeth in need of complex endodontic treatment: Influence of the endodontic treatment and quality of the restoration

OBJECTIVES

The objective of this retrospective practice-based study was to evaluate the survival of molar teeth and endodontic success after complex endodontic treatment up to 89 months.

METHODS

Endodontically (Endodontic Treatment Classification (ETC) scores II and III) treated first and second molars treated between January 2011-October 2017 within a referral setting were included. Open apices, combined surgical treatment, ETC score I, patients <18 years or with an ASA-score >2 were excluded. Cumulative survival estimates and Cox regression analysis were performed for tooth survival and endodontic healing according to the Glossary of Endodontic Terms. Restoration quality was assessed using the FDI criteria. Alpha was set at 0.05.

RESULTS

279 endodontically treated molars in 245 patients were included for survival analysis and 268 molars for endodontic success. After 89 months, the cumulative survival was 91.7 % [95 % CI: 86.8 %-94.9 %]. Absence of adjacent teeth and deviance in root canal morphology significantly decreased the probability of tooth survival. Cumulative endododontic healing rates after 48 and 89 months were 82.2 % [95 %CI: 75.7 %-87.1 %] and 51.1 [95 % CI: 20.2 %-75.5 %] respectively. Deviance in root canal morphology and inadequate coronal seal significantly decreased the probability of endodontic healing. Indirect restorations obtained higher esthetic and biological FDI scores, however no difference between direct and indirect restorations was found concerning the functional FDI score.

CONCLUSIONS

After 89 months, cumulative survival of molars in need of complex endodontic treatment was 91.7 % [95 % CI: 86.8 %-94.9 %].

CLINICAL SIGNIFICANCE

Within daily clinical practice, the dilemma of performing a complex endodontic (re)treatment or to explore other treatment options for molar teeth in need of reintervention is still urgent. Tooth survival of molar teeth with complex endodontic (re)treatment seems satisfactory up to 89 months.

Characterization of Extraction Sockets by Indirect Digital Root Analysis

This study aimed to characterize extraction sockets based on indirect digital root analysis. The outcomes of interest were estimated socket volume and dimensions of the socket orifice. A total of 420 extracted teeth, constituting 15 complete sets of permanent teeth (except third molars), were selected. Teeth were scanned to obtain STL files of the root complex for digital analysis. After digitally sectioning each root 2.0 mm apical to the cementoenamel junction (CEJ), root volume was measured in mm³ and converted to cc. Subsequently, a horizontal section plane was drawn at the most zenithal level of the buccal CEJ, and the surface area (in mm2) and buccolingual and mesiodistal linear measurements of the socket orifice (in mm) were computed. Maxillary first molars exhibited the largest mean root volume (0.451 ± 0.096 cc) and mandibular central incisors the smallest (0.106 ± 0.02 cc). Surface area analysis demonstrated that mandibular first molars presented the largest socket orifice area (78.56 ± 10.44 mm²), with mandibular central incisors presenting the smallest area (17.45 ± 1.82 mm²). Maxillary first molars showed the largest mean socket orifice buccolingual dimension (11.08 ± 0.60 mm), and mandibular first molars showed the largest mean mesiodistal dimension (9.73 ± 0.84 mm). Mandibular central incisors exhibited the smallest mean buccolingual (5.87 ± 0.26 mm) and mesiodistal (3.52 ± 0.24 mm) linear dimensions. Findings from this study can be used by clinicians to efficiently plan extraction-site management procedures (such as alveolar ridge preservation via socket grafting and sealing) and implant provisionalization therapy, and by the industry to design products that facilitate site-specific execution of these interventions.

Histological, radiological, and clinical outcomes of sinus floor elevation using a lateral approach for pre-/post-extraction of the severely compromised maxillary molars: a study protocol for a randomized controlled trial

BACKGROUND

The volume of residual alveolar bone is critical to the survival of dental implants. When the volume of alveolar bone in the posterior maxillary region is less than 4 mm, maxillary sinus floor elevation (MSFE) with the lateral approach is an effective option. Traditionally, this standard approach is usually conducted at 4-6 months after tooth extraction (standard MSFE). However, defective dentition due to extraction can impair mastication during the period of bone remodeling, especially if the molars on both sides are severely compromised and must be extracted. MSFE before extraction (modified MSFE) can take full advantage of residual tooth strength. However, the effectiveness and practicability of the modified MSFE procedure remain unknown. Therefore, the aim of this study was to compare the clinical outcomes of modified vs. standard MSFE, in order to provide references to periodontists.

METHODS/DESIGN

The study cohort included 25 adult patients (50 surgery sites) recruited from Peking University Hospital and School of Stomatology who met the inclusion criteria. The two sides of each patient will be randomly divided into two groups: a test group-modified MSFE or a control group-standard MSFE. The surgical duration and patient-reported outcomes (visual analog scale for discomfort) will be documented. Clinical indicators, including implant survival rates, mucosal conditions, and complications, will be recorded every 6 months during the 5-year follow-up period. The volume of the alveolar bone and marginal bone level will be assessed radiographically (cone-beam CT and periapical films) every 6 months. Histological analysis of biopsy samples retrieved from both sides will be performed to evaluate the biological features of the bone.

DISCUSSION

The current study will explore the implant survival rates, safety, reliability, effectiveness, and practicability of the modified MSFE procedure. Moreover, the extent of osteogenesis on the sinus floor will also be assessed. The results of this trial will provide strategies for the modified MSFE procedure to achieve ideal clinical outcomes.

TRIAL REGISTRATION

International Clinical Trials Registry Platform ChiCTR1900020648 . Registered on 1 January 2019.

Miniscrew-supported pole technique: Surgical-orthodontic approach for impacted or retained second molars in adolescents

BACKGROUND

Several treatment options have been proposed for the treatment of eruption disturbances of permanent molars. Despite being an infrequent condition, these disturbances should be solved as they can lead to important complications and play a relevant role in completing the occlusion.

FINDINGS

The presented cases involved maxillary and mandibular included second molars (M2s) respectively. Both teeth erupted successfully after the application of the miniscrew-supported pole technique, and a functional occlusion was established.

CONCLUSIONS

This technique is a surgically assisted orthodontic procedure performed to force the eruption of impacted/retained M2s. This device uses one mesial miniscrew which allows the application of relevant force to achieve the eruption of complicated retained/impacted M2s within a short period of time.

Do composite restorations in primary molar teeth have a higher survival rate following total or selective caries removal?

Study design A double-blind randomised clinical trial, conducted between June 2009 and June 2011, in a paediatric dental department in a Brazilian dental school.Study selection Children aged 3-8 years, in good general health, with deep carious lesions (caries radiographically located in the inner quarter of dentine) affecting either one or two surfaces in primary molars were eligible for inclusion. Teeth were excluded if clinical or radiographic evidence of pulpal inflammation or necrosis or clinical mobility were observed. Pre-cooperative children were also excluded.Clinical procedures and success criteria Following a coin toss, 120 teeth were randomly assigned to two groups: 55 in the total caries removal (TCR) group and 65 in the selective caries removal (SCR) group. Procedures were carried out by three paediatric dentists under local anaesthesia and restored, using a layering technique, with composite under rubber dam. Restorations were evaluated at 3, 6, 12, 18, 24 and 36 months, using the US Public Health Service (USPHS) scale, by a single-blinded and calibrated examiner. A Charlie or Delta score, on the USPHS scale, at the margins of the restorations was considered as restoration failure. Gingival bleeding score, type of cavity (one or two surfaces) and presence of caries (active or inactive) were recorded as secondary outcomes; however, presence alone did not constitute restoration failure.Results Average survival rate of restorations across all teeth was 68% after 36 months, with SCR statistically significantly lower at 57% compared to TCR at 81% (p = 0.004). Annual failure rates for SCR and TCR were 17.3% and 6.7%, respectively. Two-surface restorations had lower survival rates (58%) compared to single-surface restorations (87%) (p = 0.02). Type of cavity and gingival bleeding statistically influenced the chance of restoration failure at 36 months.Conclusions Composite restorations placed after SCR in primary molars were found to fail more often compared to those restored after TCR. Two-surface cavities and poor gingival health negatively impacted restoration success.

Success rates of coronal and partial pulpotomies in mature permanent molars: a systematic review and single-arm meta-analysis

Objectives: This systematic review aimed to evaluate the clinical and radiographic outcomes of coronal and partial pulpotomies in mature permanent molars with cariously exposed vital pulp. Method and materials: The protocol of the current review was registered in the PROSPERO database (CRD 42020190785). Articles published between January 1980 and June 2020 were searched in eight different online databases and six textbooks according to PRISMA guidelines. Eleven studies were included in the analysis of 1-year success rates, whereas five studies were included in the analyses of 2-year and > 2-year success rates for coronal pulpotomy. Two studies were included in the analyses of the 1-year and 2-year success rates for partial pulpotomy. The clinical and radiographic success rates were estimated using the DerSimonian-Laird random effect method. The risks of bias were evaluated using Cochrane RoB 2, ROBINS-I, and Newcastle-Ottawa scale assessment tools. Evidence levels were determined using the Oxford Centre for Evidence-Based Medicine (OCEBM) recommendation tool. The success rates using different pulp capping medicaments and restorative materials were analyzed using meta-regression analysis. Results: The clinical and radiographic success rates of coronal pulpotomy ranged between 92.2% and 99.4%, whilst for partial pulpotomy, the success rates ranged between 78.2% and 80.6%. Different pulp capping medicaments and restorative materials showed no significant effect on the success rates of coronal pulpotomy, but the former significantly (P < .05) affected the success rates of partial pulpotomy. Conclusion: Coronal and partial pulpotomies demonstrated a high success rate in treating cariously exposed vital pulp of mature permanent molars. Further well-designed studies with longer follow-up periods are required to validate these findings.

Evaluation of Sealing Potential of Different Repair Materials in Furcation Perforations Using Dye Penetration: An In Vitro Study

AIM

The present study aimed to assess the sealing ability of various repair materials in furcation perforations using dye penetration.

MATERIALS AND METHODS

A total of 80 human first molars from mandible with unbroken enamel surfaces, which were extracted completely for periodontal reasons, were chosen. All extracted teeth were kept in a sterile solution up until further use. Endo-access bur was used to prepare endodontic access cavity, and a high-speed long shank round bur was used to create a planned perforation on the floor of pulp. All the specimens were randomly grouped (20 teeth in each group): Group I: control; group II: Pro-Root MTA; group III: resin-modified glass-ionomer cement (RM GIC); and group IV: Biodentin. After placement of repair materials in perforated furcation, the chamber of each tooth was accessed with 2% methylene blue dye. Later, a diamond disk was used to split the teeth buccolingually. A stereomicroscope (10×) was used to visualize the highest dye penetration.

RESULTS

The least penetration was seen in teeth repaired by Biodentin group (0.88 ± 0.02), next by Pro-Root MTA group (1.24 ± 0.13) and resin-modified glass ionomer cement group (3.62 ± 0.46). A statistically significant difference was seen among different perforation repair materials by analysis of variance. A statistically significant difference (p value < 0.05) was found between each group, excluding group II v/s group IV.

CONCLUSION

This study concluded that reduced dye penetration in perforation repair along the furcations and improved sealing ability are shown by biodentine group in comparison to Pro-Root MTA and resin-modified glass-ionomer cement group.

CLINICAL SIGNIFICANCE

Root perforations along the furcation that develop due to the endodontic procedures have a remarkable damaging effect on prognosis and frequently result in loss of secondary periodontal attachment, thus resulting in early loss of the involved tooth. Therefore, the selection of biocompatible repair material aids to enhance the treatment prognosis.

Influence of Implant-Tooth Proximity on Incidence of Caries in Teeth Adjacent to Implants in Molar Sites: A Retrospective Radiographic Analysis of 300 Consecutive Implants

Implants used to replace molar teeth present issues of space distribution and crown contours that are unique to these sites. Because the diameter of the implant typically is smaller than that of the tooth being replaced, and the circular shape of the implant does not replicate the anatomy of the tooth, a large gingival embrasure area between the implant platform and adjacent tooth often results. Upon the review of radiographs of molar implants placed over an 11-year period in one private practice, the authors identified an unusually high incidence of approximal, cervical, and root caries on teeth adjacent to these implants. This retrospective radiographic study investigated the incidence of decay as related to: (1) the horizontal distance from the implant to the adjacent tooth (ie, the implant-tooth distance, or ITD) as measured at the alveolar crest, (2) the vertical distance from the apical portion of the prosthetic contact area to the implant platform, and (3) the presence of an existing restoration on the adjacent tooth. Of the three variables examined, both the horizontal distance of the implant to a natural tooth (ITD) and the presence of an existing restoration on an adjacent tooth proved to be significantly correlated with the incidence of decay. Results showed that incidence of decay ranges from 7.4% when the ITD is less than 2 mm to 40% when the ITD is ≥6 mm. The mean ITD in cases in which decay was found was 4.1 mm, and it was 3.5 mm in cases that showed no decay (P = .005). It is therefore suggested that the horizontal threshold of 4 mm be considered as the "critical ITD." The results also indicated that the presence of a previous restoration on an adjacent tooth increases the incidence of decay to a statistically significant degree with an odds ratio of 2.25 at a 95% confidence level. This information may prove useful in diagnosis and treatment planning for molar implant replacement.

Iatrogenic penetration of the mouth floor during mandibular molar extraction: A case of protracted bleeding in an emergency department and clinico-anatomical considerations

Iatrogenic perforation of the lingual cortical plate of the mandible is uncommon but it may result in injuries to various adjacent structures such as the lingual nerve, sublingual gland, submandibular duct, deep lobe of the submandibular gland, and branches of rich anastomosing plexus supplying the floor of the mouth (FOM). The aim of this article was to highlight an unusual case of protracted postoperative bleeding that was occurred due to a FOM injury during an attempt to extract a mandibular second molar. Various anatomical considerations with clinical relevance were summarized too. Even small and superficial injuries of FOM should be not misjudged but be carefully monitored, since there is a potential risk for significant haemorrhage and hematoma formation leading to airway obstruction.

Orthodontic treatment of children with class II division 1 with severe MIH involving first permanent molars extractions: A case report

BACKGROUND

Class II division 1 is the most common malocclusion in Europe. When the overjet is severe, the risk of trauma on anterior maxillary teeth as well as the risk of being bullied at school is increased. From this point of view, early treatment reduces the risk of dental fracture and increases patient self-esteem. In another hand, MIH is frequent with a prevalence of around 15% in children with country specificity, and molars in particular are difficult to treat endodontically with good long-term results when the MIH is severe. In many cases when the third molars are present, the extraction of the affected teeth followed by an orthodontic treatment remains the best solution but requires adequate orthodontic mechanics.

OBJECTIVE

The purpose of this article is to display one case of class II division1 with MIH treated by orthopaedic therapy and followed by molar extractions and fixed appliance.

Interceptive use of pendulum for advance resolution of class II patient: a guided eruption plan to reduce stress on permanent teeth root

Use of the so-called distalizing mechanics is a common treatment to correct class II malocclusion. One of the first appliances made for molar distalization was the pendulum, which resulted immediately efficient. The knowledge of pendulum efficacy, in regards to distalizing treatment in adolescence, has guided the research to analyze pendulum effect in childhood: checking the pre-eruptive, natural and distal movement of upper second premolar following first upper molar distalization in order to obtain an advance resolution on Angle's Class II patient, limited treatment time, reduced periodontal inflammation and stress on permanent teeth root. A pilot study testing the possibility of a prospective study was necessary on 6 patients treated following an accurate protocol (6 months and 1-year Rx control) and 6 patient control after one year. Statistical analysis by T-Test was done. Oral hygiene controls every month were done. Second upper bicuspid vertical (1.6mm) and sagittal (2.5mm) movement mean values allow to emphasize a distal variation of tooth axis inclination of treatment group than control group, and a second upper bicuspid distal departure from "gubernaculus dentis" of second deciduous molar in treated patients. Periodontal inflammation appears inexistent on second and first upper premolar germs after the comparison between RX exam of treatment and control groups because of exploiting deciduous teeth. Besides periodontal inflammation and teeth root stress on first upper molar of treatment group, after RX analysis, results were limited compared to control groups because of the advanced orthodontic interceptive treatment during a previous stage of first upper molar root development.

Ex vivo shaping ability of reciprocating instruments operated by new users: Reciproc versus WaveOne

OBJECTIVES

To compare two reciprocating NiTi systems operated by novices for use in curved root canals.

METHODS

Fifty mesial roots of extracted mandibular first molars, with 2-2 canal configuration, were scanned with micro-CT and divided into 2 groups according to canal length and curvature: Reciproc and WaveOne. Each system was used to prepare one of the two canals by fourth-year dental students, who were new to reciprocating files and were blinded to the system being used. After another scanning, the pre- and post-instrumentation images were compared 3-dimensionally in software.

RESULTS

Some 43 to 46% of the canal wall area remained un-instrumented. Significantly higher proportions of canals were transported towards the isthmus or furcation aspect than the mesial or external aspect. Mean transported distance was the greatest in the coronal one-third. Remaining dentine wall was the thinnest at the furcal aspect near the middle root region. No significant difference was noted between the two brands in the parameters examined.

CONCLUSIONS

Both brands of reciprocating file left similar amounts of un-instrumented canal wall, and resulted in similar extent of canal transportation.

CLINICAL RELEVANCE

NiTi reciprocating files can safely be used by new users to prepare curved root canals into a predictable shape.

Soft tissue regeneration around immediate implant placement utilizing a platelet-rich fibrin membrane and without tightly flap closure: Two case reports

RATIONALE

In this report, a combination of platelet-rich fibrin (PRF) membrane and semi-open flap technique was used to improve soft tissue regeneration in immediate implant placement in the molar region. PRF, an autologous fibrin matrix, has been widely used for soft tissue wound healing and regeneration. Semi-open flap technique is beneficial to eliminating exudates and relieving the swelling after surgery.

PATIENT CONCERNS

Case 1 was a 45-year-old female with a residual crown in the posterior maxillary region that desired a dental implant operation. Case 2 was a 24-year-old male with retained deciduous tooth that requested a restoration of his congenital absent tooth.

DIAGNOSES

In case 1, the tooth 16 was diagnosed with a residual crown, while in case 2, a deciduous tooth 75 was a retained deciduous tooth and 35 was congenital absent.

INTERVENTIONS

In both cases, immediate implant placement was installed and PRF membranes were made to improve soft tissue augmentation with semi-open flap technique. In case 1, the mixture of an organic bovine bone and blood was filled in the gap between the implant and the socket wall. Subsequently, 2 PRF membranes covered the open wound with semi-open flap. Similarly, in case 2, another 2 PRF membranes were used to improve the soft tissue regeneration, with the same semi-open flap technique as mentioned above.

OUTCOMES

In both cases, successfully soft tissue regeneration was obviously observed without postoperative infection.

LESSONS

Utilizing the PRF membrane combined with semi-open flap technique can achieve excellent soft tissue augmentation around immediate implant placement in the molar regions.

Sealing Ability of Calcium Silicate-based Materials in the Repair of Furcal Perforations: A Laboratory Comparative Study

AIM

To assess the sealing ability of two calcium silicate-based materials in the treatment of iatrogenic furcal perforations using a dye-penetration leakage model.

MATERIALS AND METHODS

Furcation perforations were performed using a size 12 round burr on the pulp chamber floor of 20 first mandibular molars. The teeth were then randomly divided into two groups, two additional molars served as negative controls. The defects were then filled with mineral trioxide aggregate (MTA) Angelus in the first group and Biodentine in the second group. Leakage at the repaired sites was then evaluated using the methylene blue dye penetration technique.

RESULTS

Significant differences in microleakage were found between the two groups at 72 hours (p < 0.001). MTA Angelus had greater dye penetration than Biodentine with a statistically significant difference. Subsequently, the sealing ability of Biodentine was significantly better than MTA Angelus (p < 0.001). However, the mean values of leakage and inadequate adhesion were significantly different from the theoretical value for both the MTA Angelus (p < 0.001) and Biodentine (p < 0.001).

CONCLUSION

The current results suggested that Biodentine possesses higher sealing quality than MTA Angelus. Yet, both materials are not ideal and still need improvement to ensure perfect adhesion in case of furcal perforation.

CLINICAL SIGNIFICANCE

This article aims to compare the sealing ability of one dental repair material over another, after iatrogenically producing a furcal perforation. Leakage resistance and sealing ability are important factors in favoring the outcome of an endodontic treatment of a tooth that could otherwise be condemned for extraction.

Clinical and Radiographic Success of Low-Level Laser Therapy Compared with Formocresol Pulpotomy Treatment in Primary Molars

Purpose: The purpose of this study was to assess and compare the clinical and radiographic success rates of low-level laser therapy (LLLT) and formocresol (FC) for pulpotomy in primary teeth. Methods: Utilizing a split-mouth technique, 106 primary molars of 36 five- to eight-year-olds were included. The teeth were selected according to specific clinical and radiographic inclusion criteria and randomly assigned to the LLLT group and FC group. A pulpotomy was performed on each molar; 53 teeth were treated with LLLT, and 53 teeth were treated using FC. Children were followed at six and 12 months for clinical and radiographic evaluation. Results: At six months, the clinical success rate was 98 percent for each group. Radiographic success was 100 percent for the LLLT group and 98 percent for the FC group. At 12 months, both groups showed a clinical success of 96.1 percent. Radiographic success at 12 months was 100 percent and 98 percent for LLLT and FC, respectively. Conclusions: Both low-level laser therapy and formocresol pulpotomy techniques showed favorable clinical and radiographic outcomes in human primary molar teeth over 12 months. Further longitudinal studies with longer follow-up periods and larger sample sizes are encouraged.